前言

我前面也写过几篇关于easypoi复杂表格导出的文章,什么一对多纵向合并、多级表头、动态表头、多个sheet等,这些我写那几篇文章之前做项目都遇到过,并且都实现出来了。

感兴趣的可以看看:
easypoi多级表头、多个sheet导出,动态导出列、动态更改表头

easypoi一对多,纵向合并单元格,并且根据内容自适应行高

我就以为大部分表格导出都难不倒我了,没想到我碰到的表格还是不够多。

多级表头中,不知道大家有没有碰到过这种表头,如下图:

在这里插入图片描述


三级下面有n个四级,一级二级下面分别只有一个二级和三级。亦或是这种:

在这里插入图片描述


我一开始寻思这种表头用easypoi的 ExcelExportEntity 实现挺简单的呀,后面我用代码写了才发现这结果完全不是我想的样子啊😂上面那两张图是想要的理想效果,实际上的结果是这样的:

在这里插入图片描述

和这样的:

在这里插入图片描述

我直接: 在这里插入图片描述

这种情况就是合并单元格只能作用于上一级,而不能跨级。比如对二级来说,四级是它子级的子级,但是它并不能因为子级(三级)有多个子级,所以子级(三级)合并了,它本身也会合并。 用easypoi来导出的话,关于这个问题,我现在没有找到解决方案。

还有一点就是我明明每列都设置了列宽,但是四级3、四级4的列宽没起作用,四级1、四级2设置的列宽倒是起作用了。

发现用 ExcelExportEntity 行不通后,有想过使用模板,但是我项目中实际用的表头比较复杂,我用模板完全不知道要怎么把表头遍历出来。。。项目里用的大概是这种形式的表头:

在这里插入图片描述

我不知道在模板里遍历每一项的时候,怎么再遍历每一项里面的list。就是遍历一级时,怎么再把每个一级下面的二级list给遍历出来。我看了easypoi的官方文档,发现有个 模板支持多层循环 的实现,但是偏偏就这一点,它文档上的图片没了。。。

在这里插入图片描述

然后我开始找其他解决办法,看过很多关于easypoi复杂表头的文章,都没有找到我这种形式的表格。直到我看某篇文章的评论区时,终于看到个有遇到和我一样问题的人了,并且贴出了参考方案,我按照这个方法,终于做出来我想要的表头了!!解决方案我就是参考的这篇文章:JAVA POI 实现EXCEL 动态表头、动态添加数据(导入导出)、 Tree结构的遍历


解决

一、表头效果

我按照上面那篇文章,终于得到我想要的表头了,效果如图:

在这里插入图片描述

在这里插入图片描述

还有下面这个横跨多行的表头:

在这里插入图片描述

设置的列宽也有作用。

再看看用easypoi ExcelExportEntity 导出来的:

在这里插入图片描述

我设置的列宽也不起作用。

二、填充数据

表头可以了,接下来就是填充内容数据了,效果如下:

在这里插入图片描述
这里就有个问题了,因为所在单位这一列有连续多行是相同内容,所以我想要合并相同内容。

1、纵向合并

于是我在原先的代码基础上,加了纵向合并功能,需要设置哪几列是遇到相同内容要合并的。

/**
 * 把数据写入到单元格
 * @param headerCellList 表头数据
 * @param datas           行内数据
 * @param sheet           工作表(excel分页)
 * @param mergeIndex      需要纵向合并的单元格列号
 * @throws Exception void
 */
private void writeSheetContent(List<ColEntity> headerCellList, List<T> datas, HSSFSheet sheet, int rowIndex,List<Integer> mergeIndex, boolean rowFlag) throws Exception {
    boolean isMerge = false;// 是否纵向合并单元格
    if (mergeIndex != null && !mergeIndex.isEmpty()) isMerge = true;
    HSSFRow row = null;
    List<ColEntity> listCol = new ArrayList<>();
    rowFlag = false;
    if (rowFlag) {//暂时没有用 后面扩展用
        for (int i = 0, index = rowIndex; i < datas.size(); i++, index++) {
            row = sheet.createRow(index);//创建行
            for (int j = 0; j < headerCellList.size(); j++) {
                createColl(row, j, headerCellList.get(j).getFieldName(), datas.get(i));
            }
        }
    } else {
        getColEntityList(headerCellList, listCol);
        Map<Integer,  Map<Integer, String>> mergeMaps = new HashMap<>();// 需要合并的列:key 列号,value为单元格内容
        Map<Integer, String> mergeMap = null;// 需要合并的行:key 行号 value 为单元格内容
        for (int i = 0, index = rowIndex; i < datas.size(); i++, index++) {
            row = sheet.createRow(index);//创建行
            for (int j = 0; j < listCol.size(); j++) {
                ColEntity c = listCol.get(j);
                //数据列
                HSSFCell col = createCol(row, c, datas.get(i));
                if (col.toString().length()>0){
                    // 需要合并 并且 当前单元格所在的列包含在要合并的列中
                    if (isMerge && mergeIndex.contains(c.getCol())){
                        if (mergeMaps.get(c.getCol()) != null){ // 如果要合并的列已经有了,则直接去拿该列的数据
                            mergeMap = mergeMaps.get(c.getCol());
                        }else {
                            mergeMap = new HashMap<>();
                        }
                        // 当前行号为key,当前单元格内容为value
                        mergeMap.put(index,col.toString()); // 将当前单元格的内容添加到当前行号中
                        mergeMaps.put(c.getCol(),mergeMap);
                    }
                }
            }
        }
        if (isMerge) mergedCells(mergeMaps,sheet);
    }
}

/**
 * 纵向合并单元格
 * @param mergeMaps 需要合并的列:key 要合并的列号,value为单元格内容
 * @param sheet
 */
private void mergedCells(Map<Integer,  Map<Integer, String>> mergeMaps,XSSFSheet sheet){
    // 遍历要合并的列
    for (Integer colNum : mergeMaps.keySet()) {
        Map<Integer, String> mergeMap = mergeMaps.get(colNum);// 当前这列每一行的内容:key为行号,value为单元格内容
        String prevValue = ""; // 上一个单元格的内容
        int start = 0; // 开始合并的行号
        int end = 0; // 结束合并的行号
        // 遍历每一行
        for (Integer row : mergeMap.keySet()) {
            String value = mergeMap.get(row); // 当前单元格的内容
            // 判断当前单元格的值和上一个单元格的值是否相同
            if (value.equals(prevValue)){
                end = row; // 相同,则更新结束合并的行号
            }else {
                // 开始合并的行号必须小于结束合并的行号
                if (start < end) {
                    System.out.println("第"+colNum+"列开始合并的行号:"+start+"\t第"+colNum+"列结束合并的行号:"+"\t"+end+"。");
                    sheet.addMergedRegion(new CellRangeAddress(start, end, colNum,colNum));
                }
                start = row;
                end = row;
                prevValue = value;
            }
        }
        // 处理最后一组相同内容的单元格
        if (start < end) {
            System.out.println("第"+colNum+"列开始合并的行号:"+start+"\t第"+colNum+"列结束合并的行号:"+"\t"+end+"。");
            sheet.addMergedRegion(new CellRangeAddress(start, end, colNum,colNum));
        }
    }
}

写好纵向合并的方法后,我们再来看看导出效果:(行号索引从0开始)

在这里插入图片描述
在这里插入图片描述
在这里插入图片描述

2、多个sheet

实现了纵向合并,项目中又根本不止一个sheet,所以我们还得实现导出多个sheet。

我在原先代码调用导出方法的基础上,再对这个方法传入的参数进行重新封装。原先是表头数据和内容数据都用的list,要实现多个sheet的话,我再用map把每个sheet的表头数据list、内容数据list给封装起来,用sheet名称为key。

/**
 * 返回workbook(单个sheet)
 * @param listTpamsColEntity 表头数据
 * @param datas           行内数据
 */
public HSSFWorkbook exportWorkbook(List<ColEntity> listTpamsColEntity, List<T> datas) throws Exception {
    splitDataToSheets(this.title,datas, listTpamsColEntity,null, false);
    ExcelStyleUtil.setStyleByType(this.workbook,null,0,null);
    return this.workbook;
}

/**
 * 返回workbook(多个sheet),这里全部sheet都用的同一个样式
 * @param titles          表头数据(key为sheet名称,value为表头数据)
 * @param datas           行内数据(key为sheet名称,value为行内数据)
 */
public HSSFWorkbook exportWorkbook(Map<String,List<ColEntity>> titles, Map<String,List<T>> datas) throws Exception {
    for (String sheetName : titles.keySet()) {
        List<ColEntity> colEntityList = titles.get(sheetName);
        List<T> tList = datas.get(sheetName);
        splitDataToSheets(sheetName,tList, colEntityList,null,false);
    }
    ExcelStyleUtil.setStyleByType(this.workbook,null,0,null);
    return this.workbook;
}

最后导出如图:
在这里插入图片描述

三、完整代码

<dependencies>
    <!-- servlet -->
    <dependency>
        <groupId>javax.servlet</groupId>
        <artifactId>servlet-api</artifactId>
        <version>2.5</version>
    </dependency>

    <!-- excel -->
    <dependency>
        <groupId>cn.afterturn</groupId>
        <artifactId>easypoi-base</artifactId>
        <version>4.4.0</version>
    </dependency>
</dependencies>

1、表头实体类

用于封装表头内容。可以将数据库查出来的动态表头数据用这个实体类封装起来,也可以直接用数据库表映射的实体类

/**
 * 表头的实体类: 在具体的项目里,可以是你从数据库里查询出来的数据
 */
public class TitleEntity {
    /**
     * id
     */
    public  String id;
    /**
     * 父级id
     */
    public  String pid;
    /**
     * 表头内容
     */
    public  String content;
    /**
     * 映射的字段名
     */
    public  String fieldName;
    /**
     * 列宽
     */
    public int width;

    private TitleEntity(){}

    public TitleEntity(String id, String pid, String content, String fieldName, int width) {
        this.id = id;
        this.pid = pid;
        this.content = content;
        this.fieldName = fieldName;
        this.width = width;
    }
    // ......省略getter、setter
}

2、单元格实体类

import java.util.ArrayList;
import java.util.List;

/**
 * 单元格
 */
public class ColEntity {
    /**
     * 单元格内容
     */
    private String content;
    /**
     * 字段名称,用户导出表格时反射调用
     */
    private String fieldName;
    /**
     * 这个单元格的集合
     */
    private List<ColEntity> cellList = new ArrayList<ColEntity>();
    /**
     * 总行数
     */
    private int totalRow;
    /**
     * 总列数
     */
    private int totalCol;
    /**
     * excel第几行
     */
    private int row;
    /**
     * excel第几列
     */
    private int col;
    /**
     * excel 跨多少行
     */
    private int rLen;
    /**
     * excel跨多少列
     */
    private int cLen;
    /**
     * 是否有子节点
     */
    private boolean hasChildren;
    /**
     * 树的级别 从0开始
     */
    private int treeStep;
    /**
     * 树的id
     */
    private String id;
    /**
     * 树的父级id
     */
    private String pid;
    /**
     * 列宽
     */
    private int width;
    
    // ......省略getter、setter
}

3、构建树形结构工具类

import com.entity.ColEntity;
import java.util.ArrayList;
import java.util.Collections;
import java.util.Iterator;
import java.util.List;

/**
 * excel poi 处理tree结构的数据 工具类
 */
public class ExcelTreeUtil {
    
    /**
     * 传入的id 必须存在list集合里
     * 获取某节点的深度
     * @param list
     * @param id   根节点
     * @param step 当前节点级别
     * @return
     */
    public static int getTreeStep(List<ColEntity> list, String id, int step) {
        if ("".equals(id) || null == id) return step;
        for (ColEntity cc : list) {
            if (id.equals(cc.getId())) {
                int temp = step + 1;
                return getTreeStep(list, cc.getPid(), temp);
            }
        }
        return step;
    }

    /**
     * 遍历所有数据 获取树最大的深度
     * @param list
     * @return
     */
    public static int getMaxStep(List<ColEntity> list) {
        List<Integer> nums = new ArrayList<>();
        for (ColEntity cc : list) {
            nums.add(getTreeStep(list, cc.getId(), 0));
        }
        return Collections.max(nums);
    }

    /**
     * 获取最底部子节点的个数 所有叶子节点个数
     * @param list
     * @param did
     * @return
     */
    public static int getDownChildren(List<ColEntity> list, String did) {
        int sum = 0;
        for (ColEntity cc : list) {
            if (did.equals(cc.getPid())) {
                sum++;
                //判断该节点 是否有子节点
                if (hasChild(list, cc)) {
                    sum += getDownChildren(list, cc.getId()) - 1;
                }
            }
        }
        return sum;
    }

    /**
     * 获取父节点
     * @param list 所有的list数据,一条一条
     * @param did  当前节点id
     * @return
     */
    public static ColEntity getParentCol(List<ColEntity> list, String did) {
        for (ColEntity cc : list) {
            if (did != null && did.equals(cc.getId())) {
                return cc;
            }
            if (did == null && did == cc.getId()) {
                return cc;
            }
        }
        return new ColEntity() {{
            setCol(0);
            setRow(0);
        }};
    }

    /**
     * 获取兄弟节点个数 这个必须是有排序的
     * @param list   所有的list数据,一条一条
     * @param ColEntity 当前节点信息
     * @return
     */
    public static int getBrotherChilNum(List<ColEntity> list, ColEntity ColEntity) {
        int sum = 0;
        for (ColEntity cc : list) {
            if (ColEntity.getId().equals(cc.getId())) {
                break;
            }
            if (!ColEntity.getPid().equals(cc.getPid())) {
                continue;
            }
            int temp = getDownChildren(list, cc.getId());
            if (temp == 0 || temp == 1) {
                sum++;
            } else {
                sum += temp;
            }
        }
        return sum;
    }

    /**
     * 根据某节点的第几层的父节点id
     * @param list 所有的list数据,一条一条
     * @param id   当前节点id
     * @param step 第几层(深度 从零开始)
     * @return
     */
    public static String getStepParentId(List<ColEntity> list, String id, int step) {
        String f_id = null;
        for (ColEntity cc : list) {
            if (id.equals(cc.getId())) {
                int cstep = getTreeStep(list, cc.getId(), 0);
                if (step == cstep) {
                    return id;
                }
                int fstep = getTreeStep(list, cc.getPid(), 0);
                if (step == fstep) {
                    f_id = cc.getPid();
                    break;
                } else {
                    getStepParentId(list, cc.getPid(), step);
                }
            }
        }
        return f_id;
    }

    /**
     * 判断是否有子节点
     * @param list 遍历的数据
     * @param node 某个节点
     * @return
     */
    public static boolean hasChild(List<ColEntity> list, ColEntity node) {
        return getChildList(list, node).size() > 0;
    }

    /**
     * 得到子节点列表
     * @param list 遍历的数据
     * @param node 某个节点
     * @return
     */
    public static List<ColEntity> getChildList(List<ColEntity> list, ColEntity node) {
        List<ColEntity> nodeList = new ArrayList<>();
        Iterator<ColEntity> it = list.iterator();
        while (it.hasNext()) {
            ColEntity n = (ColEntity) it.next();
            if (n.getPid() != null && n.getPid().equals(node.getId())) {
                nodeList.add(n);
            }
        }
        return nodeList;
    }

    /**
     * 使用递归方法建树
     * @param treeNodes
     */
    public static List<ColEntity> buildByRecursive(List<ColEntity> treeNodes, String rootID) {
        List<ColEntity> trees = new ArrayList<>();
        boolean flag = false;
        boolean sflag = false;
        for (ColEntity treeNode : treeNodes) {
            if ((rootID == null && rootID == treeNode.getId())) {
                flag = true;
            }
            if (rootID != null && rootID.equals(treeNode.getId())) {
                flag = true;
            }
            if (flag) {
                trees.add(findChildren(treeNode, treeNodes));
                flag = false;
            }
        }
        if (trees.size() <= 0) {
            for (ColEntity treeNode : treeNodes) {
                if ((rootID == null && rootID == treeNode.getPid())) {
                    sflag = true;
                }
                if (rootID != null && rootID.equals(treeNode.getPid())) {
                    sflag = true;
                }
                if (sflag) {
                    trees.add(findChildren(treeNode, treeNodes));
                    sflag = false;
                }
            }
        }
        return trees;
    }

    /**
     * 递归查找子节点
     * @param treeNodes
     * @return
     */
    public static ColEntity findChildren(ColEntity treeNode, List<ColEntity> treeNodes) {
        for (ColEntity it : treeNodes) {
            if (treeNode.getId().equals(it.getPid())) {
                if (treeNode.getCellList() == null) {
                    treeNode.setCellList(new ArrayList<>());
                }
                treeNode.getCellList().add(findChildren(it, treeNodes));
            }
        }
        return treeNode;
    }
}

4、excel导出样式工具类

import cn.afterturn.easypoi.excel.entity.params.ExcelExportEntity;
import cn.afterturn.easypoi.excel.entity.params.ExcelForEachParams;
import cn.afterturn.easypoi.excel.export.styler.IExcelExportStyler;
import org.apache.poi.ss.usermodel.*;

import java.util.List;

/**
 * excel导出样式设置工具类
 * 基础样式、自适应行高、隔行背景色
 */
public class ExcelStyleUtil implements IExcelExportStyler {
    private ExcelStyleUtil(){}

    private static final short STRING_FORMAT = (short) BuiltinFormats.getBuiltinFormat("TEXT");
    private static final short FONT_SIZE_TEN = 10;
    private static final short FONT_SIZE_ELEVEN = 11;
    private static final short FONT_SIZE_TWELVE = 12;
    private static final short height = 30;

    /**
     * 大标题样式
     */
    private CellStyle headerStyle;
    /**
     * 每列标题样式
     */
    private CellStyle titleStyle;
    /**
     * 数据行样式
     */
    private CellStyle styles;

    public ExcelStyleUtil(Workbook workbook) {
        this.init(workbook);
    }

    /**
     * 初始化样式
     * @param workbook
     */
    private void init(Workbook workbook) {
        this.headerStyle = initHeaderStyle(workbook);
        this.titleStyle = initTitleStyle(workbook,true,FONT_SIZE_ELEVEN);
        this.styles = initStyles(workbook);
    }

    @Override
    public CellStyle getHeaderStyle(short i) {
        return headerStyle;
    }

    @Override
    public CellStyle getTitleStyle(short i) {
        return titleStyle;
    }

    @Override
    public CellStyle getTemplateStyles(boolean b, ExcelForEachParams excelForEachParams) {
        return null;
    }

    @Override
    public CellStyle getStyles(boolean b, ExcelExportEntity excelExportEntity) {
        return styles;
    }

    @Override
    public CellStyle getStyles(Cell cell, int i, ExcelExportEntity entity, Object o, Object o1) {
        return getStyles(true, entity);
    }

    /**
     * 获取样式
     * @param style 1 大标题样式 2 表头样式 3 内容样式
     */
    public static CellStyle getStyles(Workbook workbook,int style) {
        CellStyle cellStyle = null;
        switch (style){
            case 1:
                cellStyle = initHeaderStyle(workbook);
                break;
            case 2:
                cellStyle = initTitleStyle(workbook,true,FONT_SIZE_ELEVEN);
                break;
            case 3:
                cellStyle = initStyles(workbook);
                break;
            default:
                cellStyle = initStyles(workbook);
                break;
        }
        cellStyle.setDataFormat(STRING_FORMAT);
        return cellStyle;
    }

    /**
     * 初始化--大标题样式
     */
    private static CellStyle initHeaderStyle(Workbook workbook) {
        CellStyle style = getBaseCellStyle(workbook);
        style.setFont(getFont(workbook, FONT_SIZE_TWELVE, true));
        return style;
    }

    /**
     * 初始化--每列标题样式
     */
    private static CellStyle initTitleStyle(Workbook workbook,boolean isBold,short size) {
        CellStyle style = getBaseCellStyle(workbook);
        style.setFont(getFont(workbook, size, isBold));
        //背景色
        style.setFillForegroundColor(IndexedColors.TAN.getIndex());
        style.setFillPattern(FillPatternType.SOLID_FOREGROUND);
        return style;
    }

    /**
     * 初始化--数据行样式
     */
    private static CellStyle initStyles(Workbook workbook) {
        CellStyle style = getBaseCellStyle(workbook);
        style.setFont(getFont(workbook, FONT_SIZE_TEN, false));
        style.setDataFormat(STRING_FORMAT);
        return style;
    }

    /**
     * 设置隔行背景色
     */
    public static CellStyle getRowBackground(Workbook workbook) {
        CellStyle style = getBaseCellStyle(workbook);
        style.setFont(getFont(workbook, FONT_SIZE_TEN,false));
        //背景色
        style.setFillForegroundColor(IndexedColors.LAVENDER.getIndex());
        style.setFillPattern(FillPatternType.SOLID_FOREGROUND);
        style.setDataFormat(STRING_FORMAT);
        return style;
    }

    /**
     * 基础样式
     */
    private static CellStyle getBaseCellStyle(Workbook workbook) {
        CellStyle style = workbook.createCellStyle();
        //下边框
        style.setBorderBottom(BorderStyle.THIN);
        //左边框
        style.setBorderLeft(BorderStyle.THIN);
        //上边框
        style.setBorderTop(BorderStyle.THIN);
        //右边框
        style.setBorderRight(BorderStyle.THIN);
        //水平居中
        style.setAlignment(HorizontalAlignment.CENTER);
        //上下居中
        style.setVerticalAlignment(VerticalAlignment.CENTER);
        //设置自动换行
        style.setWrapText(true);
        return style;
    }

    /**
     * 字体样式
     * @param size   字体大小
     * @param isBold 是否加粗
     */
    private static Font getFont(Workbook workbook, short size, boolean isBold) {
        Font font = workbook.createFont();
        //字体样式
        font.setFontName("宋体");
        //是否加粗
        font.setBold(isBold);
        //字体大小
        font.setFontHeightInPoints(size);
        return font;
    }

    /**
     * 根据type设置workbook
     * @param workbook
     * @param type 类型(0 默认 1 设置隔行背景 2 自适应行高 3 设置隔行背景同时自适应行高)
     * @param autoRowHeight 需要自适应行高的行号
     */
    public static void setStyleByType(Workbook workbook,String sheetName,int type,List<Integer> autoRowHeight){
        if (sheetName != null && sheetName.length()>0){
            Sheet sheet = workbook.getSheet(sheetName);
            setSheetStyleByType(workbook,sheet,type,autoRowHeight);
        }else {
            int sheetNum = workbook.getNumberOfSheets();
            for (int i = 0; i < sheetNum; i++) {
                Sheet sheet = workbook.getSheetAt(i);
                setSheetStyleByType(workbook,sheet,type,autoRowHeight);
            }
        }
    }

    public static void setSheetStyleByType(Workbook workbook,Sheet sheet,int type,List<Integer> autoRowHeight){
        if (type==1 || type == 3){ // 1和3,设置隔行背景
            setRowBackground(workbook,sheet);
        }
        int lastRowNum = sheet.getLastRowNum();
        for(int j = 0; j <= lastRowNum; j++) {
            Row row = sheet.getRow(j);
            row.setHeightInPoints(height); // 默认行高
            if (type==2 || type == 3){ // 2和3,设置自适应行高
                if (autoRowHeight != null && autoRowHeight.contains(j)){ // 不为空,则只有指定行号的行需要自适应行高
                    autoRowHeight(row);
                }else { // 为null,则表示全部行都需要自适应行高
                    autoRowHeight(row);
                }
            }
        }
    }

    /**
     * 偶数行设置背景色
     */
    public static void setRowBackground(Workbook workbook,Sheet sheet){
        CellStyle styles = getRowBackground(workbook);
        for(int i = 0; i <= sheet.getLastRowNum(); i ++) {
            if (i%2==0 && i>0){ // 标题用全局的标题样式,就不单独设置样式了,所以排除标题
                Row row = sheet.getRow(i);
                for(int j = 0; j < row.getPhysicalNumberOfCells(); j ++) {
                    Cell cell = row.getCell(j);
                    cell.setCellStyle(styles);
                }
            }
        }
    }

    /**
     * 设置自适应行高
     */
    public static void autoRowHeight(Row row){
        //根据内容长度设置行高
        int enterCnt = 0;
        for(int j = 0; j < row.getPhysicalNumberOfCells(); j ++) {
            Cell cell = row.getCell(j);
            if (cell != null){
                int rwsTemp = row.getCell(j).toString().length();
                //这里取每一行中的每一列字符长度最大的那一列的字符
                if (rwsTemp > enterCnt) {
                    enterCnt = rwsTemp;
                }
            }
        }
        row.setHeightInPoints(height); // 设置默认行高为35
        //如果字符长度大于35,根据内容来设置相应的行高
        if (enterCnt>height){
            long d = Math.round((double) enterCnt / (double) height)+2;
            row.setHeightInPoints(enterCnt*d);
        }
    }
}

5、excel poi导出处理工具类

import com.entity.ColEntity;
import org.apache.poi.hssf.usermodel.*;
import org.apache.poi.ss.usermodel.*;
import org.apache.poi.ss.util.CellRangeAddress;
import org.apache.poi.ss.util.RegionUtil;

import java.io.File;
import java.io.FileOutputStream;
import java.lang.reflect.Field;
import java.text.SimpleDateFormat;
import java.util.*;
import java.util.stream.Collectors;

/**
 * excel poi 处理工具
 * 概念-> 表头数据:报表的表头
 * 行内数据:表头以下的数据
 * 功能:动态生成单级,多级Excel表头,多个sheet,纵向合并单元格
 * 备注:tree型结构数据的root节点的id默认为零(0)
 */
public class ExcelPoiUtil<T> {

    /**
     * excel 对象
     */
    private HSSFWorkbook workbook;
    /**
     * 表格标题
     */
    private String title;
    /**
     * 表头样式
     */
    private CellStyle styleHead;
    /**
     * 主体样式
     */
    private CellStyle styleBody;
    /**
     * 日期格式化,默认yyyy-MM-dd HH:mm:ss
     */
    private SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");

    public HSSFWorkbook getWorkbook() {
        return workbook;
    }

    public void setWorkbook(HSSFWorkbook workbook) {
        this.workbook = workbook;
    }

    public String getTitle() {
        return title;
    }

    public void setTitle(String title) {
        this.title = title;
    }

    public CellStyle getStyleHead() {
        return styleHead;
    }

    public void setStyleHead(CellStyle styleHead) {
        this.styleHead = styleHead;
    }

    public CellStyle getStyleBody() {
        return styleBody;
    }

    public void setStyleBody(CellStyle styleBody) {
        this.styleBody = styleBody;
    }

    public SimpleDateFormat getSdf() {
        return sdf;
    }

    public void setSdf(SimpleDateFormat sdf) {
        this.sdf = sdf;
    }

    /**
     * 无参数 初始化 对象
     */
    public ExcelPoiUtil() {
        this.title = "sheet1";
        this.workbook = new HSSFWorkbook();
        init();
    }

    public ExcelPoiUtil(String title) {
        this.title = title;
        this.workbook = new HSSFWorkbook();
        init();
    }

    /**
     * 内部统一调用的样式初始化
     */
    private void init() {
        this.styleHead = ExcelStyleUtil.getStyles(workbook,2);
        this.styleBody = ExcelStyleUtil.getStyles(workbook,3);
    }

    /**
     * 返回workbook
     * @param listTpamsColEntity 表头数据
     * @param datas           行内数据
     */
    public HSSFWorkbook exportWorkbook(List<ColEntity> listTpamsColEntity, List<T> datas) throws Exception {
        splitDataToSheets(this.title,datas, listTpamsColEntity,null, false);
        ExcelStyleUtil.setStyleByType(this.workbook,null,0,null);
        return this.workbook;
    }

    /**
     * 返回workbook
     * @param listTpamsColEntity 表头数据
     * @param datas           行内数据
     * @param mergeIndex      需要纵向合并的单元格列号(默认有横向合并)
     */
    public HSSFWorkbook exportWorkbook(List<ColEntity> listTpamsColEntity, List<T> datas,List<Integer> mergeIndex) throws Exception {
        splitDataToSheets(this.title,datas, listTpamsColEntity, mergeIndex,false);
        ExcelStyleUtil.setStyleByType(this.workbook,null,0,null);
        return this.workbook;
    }

    /**
     * 返回workbook
     * @param listTpamsColEntity 表头数据
     * @param datas           行内数据
     * @param type            类型(0 默认 1 设置隔行背景 2 自适应行高 3 设置隔行背景同时自适应行高)
     * @param autoRowHeight   需要自适应行高的行号
     */
    public HSSFWorkbook exportWorkbook(List<ColEntity> listTpamsColEntity, List<T> datas,int type,List<Integer> autoRowHeight) throws Exception {
        splitDataToSheets(this.title,datas, listTpamsColEntity,null, false);
        ExcelStyleUtil.setStyleByType(this.workbook,null,type,autoRowHeight);
        return this.workbook;
    }

    /**
     * 返回workbook
     * @param listTpamsColEntity 表头数据
     * @param datas           行内数据
     * @param type            类型(0 默认 1 设置隔行背景 2 自适应行高 3 设置隔行背景同时自适应行高)
     * @param autoRowHeight   需要自适应行高的行号
     * @param mergeIndex      需要纵向合并的单元格列号(默认有横向合并)
     */
    public HSSFWorkbook exportWorkbook(List<ColEntity> listTpamsColEntity, List<T> datas,int type,List<Integer> autoRowHeight,List<Integer> mergeIndex) throws Exception {
        splitDataToSheets(this.title,datas, listTpamsColEntity,mergeIndex, false);
        ExcelStyleUtil.setStyleByType(this.workbook,null,type,autoRowHeight);
        return this.workbook;
    }

    /**
     * 返回workbook(多个sheet),这里全部sheet都用的同一个样式
     * @param titles          表头数据(key为sheet名称,value为表头数据)
     * @param datas           行内数据(key为sheet名称,value为行内数据)
     * @param type            样式类型,每个sheet都用这个(0 默认 1 设置隔行背景 2 自适应行高 3 设置隔行背景同时自适应行高)
     * @param autoRowHeight  需要自适应行高的行号,每个sheet都用这个
     * @param mergeIndex     需要纵向合并的单元格列号(默认有横向合并),每个sheet都用这个
     */
    public HSSFWorkbook exportWorkbook(Map<String,List<ColEntity>> titles, Map<String,List<T>> datas,int type,List<Integer> autoRowHeight,List<Integer> mergeIndex) throws Exception {
        for (String sheetName : titles.keySet()) {
            List<ColEntity> colEntityList = titles.get(sheetName);
            List<T> tList = datas.get(sheetName);
            splitDataToSheets(sheetName,tList, colEntityList,mergeIndex,false);
        }
        ExcelStyleUtil.setStyleByType(this.workbook,null,type,autoRowHeight);
        return this.workbook;
    }

    /**
     * 返回workbook(多个sheet),这里多个sheet都有不同样式
     * @param titles          表头数据(key为sheet名称,value为表头数据)
     * @param datas           行内数据(key为sheet名称,value为行内数据)
     * @param types           每个sheet的类型,key为sheet名称(0 默认 1 设置隔行背景 2 自适应行高 3 设置隔行背景同时自适应行高)
     * @param autoRowHeights  每个sheet需要自适应行高的行号
     * @param mergeIndexs     每个sheet需要纵向合并的单元格列号(默认有横向合并)
     */
    public HSSFWorkbook exportWorkbook(Map<String,List<ColEntity>> titles, Map<String,List<T>> datas,Map<String,Integer> types,
                                       Map<String,List<Integer>> autoRowHeights,Map<String,List<Integer>> mergeIndexs) throws Exception {
        for (String sheetName : titles.keySet()) {
            List<ColEntity> colEntityList = titles.get(sheetName);
            List<T> tList = datas.get(sheetName);
            int type = types == null ? 0 : types.get(sheetName) == null ? 0 : types.get(sheetName);
            List<Integer> autoRowHeight = autoRowHeights == null ? null : autoRowHeights.get(sheetName);
            List<Integer> mergeIndex = mergeIndexs == null ? null : mergeIndexs.get(sheetName);
            splitDataToSheets(sheetName,tList, colEntityList,mergeIndex,false);
            ExcelStyleUtil.setStyleByType(this.workbook,sheetName,type,autoRowHeight);
        }
        return this.workbook;
    }

    /**
     * 保存excel到本机指定的路径
     * @param workbook
     * @param filePath
     */
    public void save(HSSFWorkbook workbook, String filePath) {
        File file = new File(filePath);
        if (!file.getParentFile().exists()) {
            file.getParentFile().mkdirs();
        }
        FileOutputStream fOut = null;
        try {
            fOut = new FileOutputStream(file);
            workbook.write(fOut);
            fOut.flush();
        } catch (Exception e) {
            e.printStackTrace();
        }
        try {
            if (null != fOut) {
                fOut.close();
            }
        } catch (Exception e1) {
        }
    }

    /**
     * 导出Excel,适用于web导出excel
     * @param sheet           excel
     * @param data            行内数据
     * @param headerCellList 表头数据
     * @param mergeIndex      需要纵向合并的单元格列号(默认有横向合并)
     * @param rowFlag         输出展示数据的结构(表头下面行的数据)
     */
    private void writeSheet(HSSFSheet sheet, List<T> data, List<ColEntity> headerCellList,List<Integer> mergeIndex,boolean rowFlag) throws Exception {
        sheet = createHead(sheet, headerCellList.get(0).getTotalRow(), headerCellList.get(0).getTotalCol());
        createHead(headerCellList, sheet, 0);
        writeSheetContent(headerCellList, data, sheet, headerCellList.get(0).getTotalRow(),mergeIndex, rowFlag);
    }

    /**
     * 拆分sheet,因为每个sheet不能超过65535,否则会报异常
     * @param sheetName       sheet名称
     * @param data            行内数据
     * @param headerCellList 表头数据
     * @param mergeIndex      需要纵向合并的单元格列号(默认有横向合并)
     * @param rowFlag         输出展示数据的结构(表头下面行的数据)
     */
    private void splitDataToSheets(String sheetName,List<T> data, List<ColEntity> headerCellList,List<Integer> mergeIndex,boolean rowFlag) throws Exception {
        int dataCount = data.size();
        int maxColEntity = 65535;
        int pieces = dataCount / maxColEntity;
        for (int i = 1; i <= pieces; i++) {
            HSSFSheet sheet = this.workbook.createSheet(sheetName + i);
            List<T> subList = data.subList((i - 1) * maxColEntity, i * maxColEntity);
            writeSheet(sheet, subList, headerCellList,mergeIndex,rowFlag);
        }
        HSSFSheet sheet = this.workbook.createSheet(sheetName);
        writeSheet(sheet, data.subList(pieces * maxColEntity, dataCount), headerCellList,mergeIndex,rowFlag);
    }

    /**
     * 把数据写入到单元格
     * @param headerCellList 表头数据
     * @param datas           行内数据
     * @param sheet           工作表(excel分页)
     * @param mergeIndex      需要纵向合并的单元格列号(默认有横向合并)
     * @throws Exception void
     */
    private void writeSheetContent(List<ColEntity> headerCellList, List<T> datas, HSSFSheet sheet, int rowIndex,List<Integer> mergeIndex, boolean rowFlag) throws Exception {
        boolean isMerge = false;// 是否纵向合并单元格
        if (mergeIndex != null && !mergeIndex.isEmpty()) isMerge = true;
        HSSFRow row = null;
        List<ColEntity> listCol = new ArrayList<>();
        rowFlag = false;
        if (rowFlag) {//暂时没有用 后面扩展用
            for (int i = 0, index = rowIndex; i < datas.size(); i++, index++) {
                row = sheet.createRow(index);//创建行
                for (int j = 0; j < headerCellList.size(); j++) {
                    createColl(row, j, headerCellList.get(j).getFieldName(), datas.get(i));
                }
            }
        } else {
            getColEntityList(headerCellList, listCol);
            Map<Integer,  Map<Integer, String>> mergeMaps = new HashMap<>();// 需要合并的列:key 列号,value为单元格内容
            Map<Integer, String> mergeMap = null;// 需要合并的行:key 行号 value 为单元格内容
            for (int i = 0, index = rowIndex; i < datas.size(); i++, index++) {
                row = sheet.createRow(index);//创建行
                for (int j = 0; j < listCol.size(); j++) {
                    ColEntity c = listCol.get(j);
                    //数据列
                    HSSFCell col = createCol(row, c, datas.get(i));
                    if (col.toString().length()>0){
                        // 需要合并 并且 当前单元格所在的列包含在要合并的列中
                        if (isMerge && mergeIndex.contains(c.getCol())){
                            if (mergeMaps.get(c.getCol()) != null){ // 如果要合并的列已经有了,则直接去拿该列的数据
                                mergeMap = mergeMaps.get(c.getCol());
                            }else {
                                mergeMap = new HashMap<>();
                            }
                            // 当前行号为key,当前单元格内容为value
                            mergeMap.put(index,col.toString()); // 将当前单元格的内容添加到当前行号中
                            mergeMaps.put(c.getCol(),mergeMap);
                        }
                    }
                }
            }
            if (isMerge) mergedCells(mergeMaps,sheet);
        }
    }

    /**
     * 纵向合并单元格
     * @param mergeMaps 需要合并的列:key 要合并的列号,value为单元格内容
     * @param sheet
     */
    private void mergedCells(Map<Integer,  Map<Integer, String>> mergeMaps,XSSFSheet sheet){
        // 遍历要合并的列
        for (Integer colNum : mergeMaps.keySet()) {
            Map<Integer, String> mergeMap = mergeMaps.get(colNum);// 当前这列每一行的内容:key为行号,value为单元格内容
            String prevValue = ""; // 上一个单元格的内容
            int start = 0; // 开始合并的行号
            int end = 0; // 结束合并的行号
            // 遍历每一行
            for (Integer row : mergeMap.keySet()) {
                String value = mergeMap.get(row); // 当前单元格的内容
                // 判断当前单元格的值和上一个单元格的值是否相同
                if (value.equals(prevValue)){
                    end = row; // 相同,则更新结束合并的行号
                }else {
                    // 开始合并的行号必须小于结束合并的行号
                    if (start < end) {
                        System.out.println("第"+colNum+"列开始合并的行号:"+start+"\t第"+colNum+"列结束合并的行号:"+"\t"+end+"。");
                        sheet.addMergedRegion(new CellRangeAddress(start, end, colNum,colNum));
                    }
                    start = row;
                    end = row;
                    prevValue = value;
                }
            }
            // 处理最后一组相同内容的单元格
            if (start < end) {
                System.out.println("第"+colNum+"列开始合并的行号:"+start+"\t第"+colNum+"列结束合并的行号:"+"\t"+end+"。");
                sheet.addMergedRegion(new CellRangeAddress(start, end, colNum,colNum));
            }
        }
    }

    /**
     * 根据list 来创建单元格 暂时没有用
     * @param row
     * @param j
     * @param finame
     * @param t
     */
    private void createColl(HSSFRow row, int j, String finame, T t) {
        HSSFCell cell = row.createCell(j);  //创建单元格
        cell.setCellStyle(this.styleBody); //设置单元格样式
        String text = "";
        if (t instanceof List) {
            List<Map> temp = (List<Map>) t;
            if (j >= temp.size()) {
                return;
            }
            text = String.valueOf(temp.get(j).get(finame) == null ? "" : temp.get(j).get(finame));
        }
        HSSFRichTextString richString = new HSSFRichTextString(text);
        cell.setCellValue(richString);
    }

    /**
     * 把ColEntity的ColEntityList整理成一个list<ColEntity> 过滤表头的脏数据
     * @param list    表头数据
     * @param listCol 返回新的list
     */
    private void getColEntityList(List<ColEntity> list, List<ColEntity> listCol) {
        for (ColEntity ColEntity : list) {
            if (ColEntity.getFieldName() != null) {
                listCol.add(ColEntity);
            }
            List<ColEntity> listChildren = ColEntity.getCellList();
            if (listChildren.size() > 0) {
                getColEntityList(listChildren, listCol);
            }
        }
    }

    /**
     * 创建行
     * @param row         Excel对应的行
     * @param tpamsColEntity 当前单元格属性
     * @param v
     * @param j
     * @return
     * @throws Exception
     */
    public int createRowVal(HSSFRow row, ColEntity tpamsColEntity, T v, int j) throws Exception {
        //遍历标题
        if (tpamsColEntity.getCellList() != null && tpamsColEntity.getCellList().size() > 0) {
            for (int i = 0; i < tpamsColEntity.getCellList().size(); i++) {
                createRowVal(row, tpamsColEntity.getCellList().get(i), v, j);
            }
        } else {
            createCol(row, tpamsColEntity, v);
        }
        return j;
    }

    /**
     * 创建单元格
     * @param row         Excel对应的行
     * @param colEntity 当前单元格对象
     * @param v
     * @throws Exception
     */
    public HSSFCell createCol(HSSFRow row, ColEntity colEntity, T v) throws Exception {
        HSSFCell cell = row.createCell(colEntity.getCol());  //创建单元格
        cell.setCellStyle(this.styleBody); //设置单元格样式
        final Object[] value = {null};
        if (v instanceof Map) {
            Map m = (Map) v;
            m.forEach((k, val) -> {
                if (k.equals(colEntity.getFieldName()) && !colEntity.isHasChildren()) {
                    value[0] = val;
                }
            });
        } else {
            Class<?> cls = v.getClass();// 拿到该类
            Field[] fields = cls.getDeclaredFields();// 获取实体类的所有属性,返回Field数组
            for (int i = 0; i < fields.length; i++) {
                Field f = fields[i];
                f.setAccessible(true); // 设置些属性是可以访问的
                if (colEntity.getFieldName().equals(f.getName()) && !colEntity.isHasChildren()){
                    value[0] = f.get(v);
                }
                if (value[0] instanceof Date) {
                    value[0] = parseDate((Date) value[0]);
                }
            }
        }
        if (value[0] != null) {
            HSSFRichTextString richString = new HSSFRichTextString(value[0].toString());
            cell.setCellValue(richString);
        }
        return cell;
    }

    /**
     * 时间转换
     * @param date
     * @return String
     */
    private String parseDate(Date date) {
        String dateStr = "";
        try {
            dateStr = this.sdf.format(date);
        } catch (Exception e) {
            e.printStackTrace();
        }
        return dateStr;
    }


    /**
     * 根据数据的行数和列数,在excel创建单元格cell
     * @param sheetCo excel分页
     * @param r       excel 行数
     * @param c       excel 列数
     * @return
     */
    public HSSFSheet createHead(HSSFSheet sheetCo, int r, int c) {
        for (int i = 0; i < r; i++) {
            HSSFRow row = sheetCo.createRow(i);
            for (int j = 0; j < c; j++) {
                HSSFCell cell = row.createCell(j);
            }
        }
        return sheetCo;
    }

    /**
     * 使用递归 在excel写入表头数据 支持单级,多级表头的创建
     * @param cellList 表头数据
     * @param sheetCo  哪个分页
     * @param rowIndex 当前Excel的第几行
     */
    public void createHead(List<ColEntity> cellList, HSSFSheet sheetCo, int rowIndex) {
        HSSFRow row = sheetCo.getRow(rowIndex);
        int len = cellList.size();//当前行 有多少列
        for (int i = 0; i < len; i++) {//i是headers的索引,n是Excel的索引 多级表头
            ColEntity colEntity = cellList.get(i);
            //创建这一行的第几列单元格
            int r = colEntity.getRow();
            int rLen = colEntity.getRLen();
            int c = colEntity.getCol();
            int cLen = colEntity.getCLen();
            int endR = r + rLen;
            //解决表头导出时多一行问题
            if(endR > r){
                endR--;
            }
            int endC = c + cLen;
            if (endC > c) {
                endC--;
            }
            HSSFCell cell = row.getCell(c);
            HSSFRichTextString text = new HSSFRichTextString(colEntity.getContent());
            cell.setCellStyle(this.styleHead); //设置表头样式
            cell.setCellValue(text);
            // 合并单元格
            CellRangeAddress cra = new CellRangeAddress(r, endR, c, endC);
            //todo debug
            if (cra.getNumberOfCells() > 1) {
                sheetCo.addMergedRegion(cra);
            }
            sheetCo.setColumnWidth(c,colEntity.getWidth()*256);// 设置列宽
            // 使用RegionUtil类为合并后的单元格添加边框
            RegionUtil.setBorderBottom(BorderStyle.THIN, cra, sheetCo); // 下边框
            RegionUtil.setBorderLeft(BorderStyle.THIN, cra, sheetCo); // 左边框
            RegionUtil.setBorderRight(BorderStyle.THIN, cra, sheetCo); // 有边框
            if (colEntity.isHasChildren()) {
                rowIndex = r + 1;
                createHead(colEntity.getCellList(), sheetCo, rowIndex);
            }
        }
    }

    /**
     * 转换成ColEntity对象
     * 支持List<T>的数据结构:map String ,只能是单级的数据
     * @param list 需要转换的数据
     */
    public List<ColEntity> colEntityTransformer(List<T> list) {
        List<ColEntity> lc = new ArrayList<>();
        if (list.get(0) instanceof Map) {
            final int[] i = {1};
            for (Map<String, String> m : (List<Map<String, String>>) list) {
                m.forEach((k, val) -> {
                    ColEntity tpamsColEntity = new ColEntity();
                    tpamsColEntity.setId(String.valueOf(i[0]));
                    tpamsColEntity.setPid("0");
                    tpamsColEntity.setContent(k);
                    tpamsColEntity.setFieldName(val);
                    tpamsColEntity.setWidth(20);
                    lc.add(tpamsColEntity);
                    i[0]++;
                });
            }
        } else {
            int i = 1;
            for (String s : (List<String>) list) {
                ColEntity tpamsColEntity = new ColEntity();
                tpamsColEntity.setId(String.valueOf(i));
                tpamsColEntity.setPid("0");
                tpamsColEntity.setContent(s);
                tpamsColEntity.setFieldName(null);
                tpamsColEntity.setWidth(20);
                lc.add(tpamsColEntity);
                i++;
            }
        }
        setParm(lc, "0");//处理一下
        List<ColEntity> s = ExcelTreeUtil.buildByRecursive(lc, "0");
        setColNum(lc, s);
        return s;
    }

    /**
     * 转换成ColEntity对象 返回tree数据结构
     * 支持:List<map>、某个具体对象(entity)数据的转换
     * @param list  需要转换的数据
     * @param parm {id,pid,content,fieldName,width} 这几个字段对应的是封装表头实体类的字段,
     *             比如我用的是TitleEntity封装的表头,则这五个key对应的value就是TitleEntity的字段名。
     *             也就是说这五个key对应的value需要和第一个参数传入的 T(某个具体对象) 的字段对应。
     *             id:       当前节点id 字段的名称       主键
     *             pid:      当前节点的父节点id          字段名称
     *             content:  当前节点所在单元格的内容     字段名称
     *             fieldName:填充行内数据时,映射的字段名  字段名称
     *             width:    列宽                      字段名称
     * @param rootid    rootid的值
     */
    public List<ColEntity> colEntityTransformer(List<T> list, Map<String,String> parm,String rootid) throws Exception {
        List<ColEntity> lc = new ArrayList<>();
        if (list.get(0) instanceof Map) {
            for (Map m : (List<Map>) list) {
                ColEntity colEntity = new ColEntity();
                m.forEach((k, val) -> {
                    if (parm.get("id").equals(k)) {
                        colEntity.setId(String.valueOf(val));
                    }
                    if (parm.get("pid").equals(k)) {
                        colEntity.setPid((String) val);
                    }
                    if (parm.get("content").equals(k)) {
                        colEntity.setContent((String) val);
                    }
                    if (parm.get("fieldName") != null && parm.get("fieldName").equals(k)) {
                        colEntity.setFieldName((String) val);
                    }
                    if (parm.get("width") != null && parm.get("width").equals(k)) {
                        colEntity.setWidth(Integer.parseInt(val.toString()));
                    }
                });
                lc.add(colEntity);
            }
        } else {
            for (T t : list) { // 反射
                ColEntity colEntity = new ColEntity();
                Class cls = t.getClass();
                Field[] fs = cls.getDeclaredFields();
                for (int i = 0; i < fs.length; i++) {
                    Field f = fs[i];
                    f.setAccessible(true); // 设置些属性是可以访问的
                    if (parm.get("id").equals(f.getName()) && f.get(t) != null) {
                        colEntity.setId(f.get(t).toString());
                    }
                    if (parm.get("pid").equals(f.getName()) && f.get(t) != null) {
                        colEntity.setPid(f.get(t).toString());
                    }
                    if (parm.get("content").equals(f.getName()) && f.get(t) != null) {
                        colEntity.setContent(f.get(t).toString());
                    }
                    if (f.get(t) != null && parm.get("fieldName") != null && parm.get("fieldName").equals(f.getName())) {
                        colEntity.setFieldName(f.get(t).toString());
                    }
                    if (parm.get("width").equals(f.getName()) && f.get(t) != null) {
                        colEntity.setWidth(Integer.parseInt(f.get(t).toString()));
                    }
                }
                lc.add(colEntity);
            }
        }
        setParm(lc, rootid); // 处理基础参数
        List<ColEntity> s = ExcelTreeUtil.buildByRecursive(lc, rootid); // 构建树结构
        setColNum(lc, s);
        return s;
    }

    /**
     * 设置基础的参数
     * @param list
     */
    public static void setParm(List<ColEntity> list, String rootid) {
        int row = 0; //excel第几行
        int rLen = 0; //excel 跨多少行
        int totalRow = ExcelTreeUtil.getMaxStep(list);
        int totalCol = ExcelTreeUtil.getDownChildren(list, rootid);
        for (int i = 0; i < list.size(); i++) {
            ColEntity poit = list.get(i);
            int tree_step = ExcelTreeUtil.getTreeStep(list, poit.getPid(), 0);//往上遍历tree
            poit.setTreeStep(tree_step);
            poit.setRow(tree_step);//设置第几行
            //判断是否有节点
            boolean hasCh = ExcelTreeUtil.hasChild(list, poit);
            poit.setHasChildren(hasCh);
            if (hasCh) {
                poit.setRLen(0);//设置跨多少行
            } else {
                if (tree_step < totalRow) {
                    rLen = totalRow - tree_step;
                }
                poit.setRLen(rLen);
            }
            poit.setTotalRow(totalRow);
            poit.setTotalCol(totalCol);
        }
    }

    /**
     * 设置基础的参数
     * @param list     所有list数据,一条一条
     * @param treeList 转成tree结构的list
     */
    public static void setColNum(List<ColEntity> list, List<ColEntity> treeList) {
        //int col = pcIndex;//excel第几列
        //int cLen ;//xcel跨多少列
        List<ColEntity> new_list = new ArrayList<>();//新的遍历list
        for (int i = 0; i < treeList.size(); i++) {
            ColEntity poit = treeList.get(i);
            //String temp_id = ExcelTreeUtil.getStepParentId(list,poit.getId() ,1);
            int col = ExcelTreeUtil.getParentCol(list, poit.getPid()).getCol();
            int brotherCol = ExcelTreeUtil.getBrotherChilNum(list, poit);
            poit.setCol(col + brotherCol);
            int cLen = ExcelTreeUtil.getDownChildren(list, poit.getId());
            if (cLen <= 1) {
                cLen = 0;
            }
            //else  cLen--;
            poit.setCLen(cLen);//设置跨多少列
            if (poit.getCellList().size() > 0) {
                new_list.addAll(poit.getCellList());
            }
        }
        if (new_list.size() > 0) {
            setColNum(list, new_list);
        }
    }
}

6、测试

import com.entity.ColEntity;
import com.entity.TitleEntity;
import com.google.common.collect.ImmutableMap;
import com.util.ExcelPoiUtil;
import org.apache.poi.hssf.usermodel.HSSFWorkbook;

import java.util.*;

/**
 * 测试
 */
public class TestMain {

    static Map<String,List<ColEntity>> heads = new HashMap<>();// 最终导出的多个sheet的表头
    static Map<String,List<Map<String, String>>> datas = new HashMap<>();// 最终导出的多个sheet的内容
    static Map<String,Integer> types = new HashMap<>();// 最终导出的每个sheet的样式类型
    static Map<String,List<Integer>> autoRowHeights = new HashMap<>();// 最终导出的每个sheet的需要自适应行高的行号
    static Map<String,List<Integer>> mergeIndexs = new HashMap<>();// 最终导出的每个sheet的需要纵向合并的单元格列号

    public static void main(String[] args) throws Exception {
        单级表头();
        多级表头Map();
        多级表头Obj();
        多级表头Obj1();
        多级表头Obj2();
        纵向合并单元格();
        // 多个sheet导出
        ExcelPoiUtil excelTool = new ExcelPoiUtil();
        //HSSFWorkbook workbook = excelTool.exportWorkbook(heads, datas, 0, null, null); // 这里多个sheet都用的同一个样式
        HSSFWorkbook workbook = excelTool.exportWorkbook(heads, datas, types, null, mergeIndexs);
        excelTool.save(workbook,"C:\\Users\\Administrator\\Desktop\\多个sheet.xls");
    }

    public static void 单级表头() throws Exception {
        //单级的表头==============================================================
        Map<String, String> map = new HashMap<String, String>();
        map.put("登录名", "u_login_id");
        Map<String, String> map1 = new HashMap<String, String>();
        map1.put("用户名", "u_name");
        Map<String, String> map2 = new HashMap<String, String>();
        map2.put("角色", "u_role");
        Map<String, String> map3 = new HashMap<String, String>();
        map3.put("部门", "u_dep");
        Map<String, String> map4 = new HashMap<String, String>();
        map4.put("用户类型", "u_type");
        List<Map<String, String>> titleList = new ArrayList<>();
        titleList.add(map);
        titleList.add(map1);
        titleList.add(map2);
        titleList.add(map3);
        titleList.add(map4);
        //单级的 行内数据
        List<Map<String, String>> rowList = new ArrayList<>();
        for (int i = 0; i < 7; i++) {
            Map<String, String> m = new HashMap<String, String>();
            m.put("u_login_id", "登录名" + i);
            m.put("u_name", "张三" + i);
            m.put("u_role", "角色" + i);
            m.put("u_dep", "部门" + i);
            m.put("u_type", "用户类型" + i);
            rowList.add(m);
        }
        ExcelPoiUtil excelTool = new ExcelPoiUtil("单级表头的表格");
        List<ColEntity> titleData = excelTool.colEntityTransformer(titleList);
        HSSFWorkbook workbook = excelTool.exportWorkbook(titleData, rowList,1,null);
        excelTool.save(workbook,"C:\\Users\\Administrator\\Desktop\\单级表头.xlsx");
    }

    public static void 多级表头Map() throws Exception {
        List<Map<String,String>> titleList=new ArrayList<>();
        Map<String,String> titleMap=new HashMap<String,String>();
        titleMap.put("id","11");titleMap.put("pid","0");titleMap.put("content","登录名");titleMap.put("fieldName","u_login_id");titleMap.put("width","20");
        Map<String,String> titleMap1=new HashMap<String,String>();
        titleMap1.put("id","1");titleMap1.put("pid","0");titleMap1.put("content","姓名");titleMap1.put("fieldName","u_name");titleMap1.put("width","20");
        Map<String,String> titleMap2=new HashMap<String,String>();
        titleMap2.put("id","2");titleMap2.put("pid","0");titleMap2.put("content","角色加部门");titleMap2.put("fieldName",null);titleMap2.put("width","20");
        Map<String,String> titleMap3=new HashMap<String,String>();
        titleMap3.put("id","3");titleMap3.put("pid","2");titleMap3.put("content","角色");titleMap3.put("fieldName","u_role");titleMap3.put("width","15");
        Map<String,String> titleMap4=new HashMap<String,String>();
        titleMap4.put("id","4");titleMap4.put("pid","2");titleMap4.put("content","部门");titleMap4.put("fieldName","u_dep");titleMap4.put("width","15");
        Map<String,String> titleMap5=new HashMap<String,String>();
        titleMap5.put("id","22");titleMap5.put("pid","0");titleMap5.put("content","角色加部门1");titleMap5.put("fieldName",null);titleMap5.put("width","20");
        Map<String,String> titleMap6=new HashMap<String,String>();
        titleMap6.put("id","22_1");titleMap6.put("pid","22");titleMap6.put("content","角色1");titleMap6.put("fieldName","u_role");titleMap6.put("width","10");
        Map<String,String> titleMap7=new HashMap<String,String>();
        titleMap7.put("id","22_2");titleMap7.put("pid","22");titleMap7.put("content","部门1");titleMap7.put("fieldName","u_dep");titleMap7.put("width","10");
        titleList.add(titleMap); titleList.add(titleMap1); titleList.add(titleMap2); titleList.add(titleMap3); titleList.add(titleMap4);
        titleList.add(titleMap5); titleList.add(titleMap6); titleList.add(titleMap7);
        // 单级的 行内数据
        List<Map<String, String>> rowList = new ArrayList<>();
        for (int i = 0; i < 7; i++) {
            Map<String, String> m = new HashMap<String, String>();
            m.put("u_login_id", "登录名zx" + i);
            m.put("u_name", "张三" + i);
            m.put("u_role", "角色" + i);
            m.put("u_dep", "部门" + i);
            m.put("u_type", "用户类型" + i);
            rowList.add(m);
        }
        ExcelPoiUtil excelTool = new ExcelPoiUtil("List<Map>多级表头");
        Map<String,String> param = ImmutableMap.<String, String>builder().put("id", "id").put("pid", "pid")
                .put("content", "content").put("fieldName", "fieldName").put("width", "width").build();
        List<ColEntity> titleData = excelTool.colEntityTransformer(titleList,param, "0");
        //HSSFWorkbook workbook = excelTool.exportWorkbook(titleData, rowList);
        //excelTool.save(workbook,"C:\\Users\\Administrator\\Desktop\\多级表头Map.xlsx");
        heads.put("List<Map>多级表头",titleData);// 每个sheet的表头,sheet名称为key
        datas.put("List<Map>多级表头",rowList);// 每个sheet的内容,sheet名称为key
        types.put("List<Map>多级表头",0);// 每个sheet的样式类型,sheet名称为key
    }

    public static void 多级表头Obj() throws Exception {
        List<TitleEntity> titleList = new ArrayList<>();
        titleList.add(new TitleEntity("0", null, "总表", null,20));
        titleList.add(new TitleEntity("11", "0", "登录名2", "u_login_id",15));
        titleList.add(new TitleEntity("1", "0", "姓名", "u_name",15));
        titleList.add(new TitleEntity("2", "0", "角色加部门", null,20));
        titleList.add(new TitleEntity("3", "2", "角色", "u_role",20));
        titleList.add(new TitleEntity("4", "2", "部门", "u_dep",20));
        titleList.add(new TitleEntity("33", "0", "角色加部门1", null,15));
        titleList.add(new TitleEntity("33_1", "33", "角色33", "u_role",15));
        titleList.add(new TitleEntity("33_2", "33_1", "部门33", "u_dep",15));
        titleList.add(new TitleEntity("44", "0", "角色加部门2", null,10));
        titleList.add(new TitleEntity("44_1", "44", "角色44", "u_role",10));
        titleList.add(new TitleEntity("44_2", "44", "部门44", "u_dep",10));
        titleList.add(new TitleEntity("1_1", "1", "姓名1", "u_name",15));
        titleList.add(new TitleEntity("44_3", "44_2", "44_2", "u_dep",10));
        //单级的 行内数据
        List<Map<String, String>> rowList = new ArrayList<>();
        for (int i = 0; i < 7; i++) {
            Map<String, String> m = new HashMap<String, String>();
            m.put("u_login_id", "登录名" + i);
            m.put("u_name", "张三" + i);
            m.put("u_role", "角色" + i);
            m.put("u_dep", "部门" + i);
            m.put("u_type", "用户类型" + i);
            rowList.add(m);
        }
        ExcelPoiUtil excelTool = new ExcelPoiUtil("实体类(entity)多级表头表格");
        Map<String,String> param = ImmutableMap.<String, String>builder().put("id", "id").put("pid", "pid")
                .put("content", "content").put("fieldName", "fieldName").put("width", "width").build();
        List<ColEntity> titleData = excelTool.colEntityTransformer(titleList, param, "0");
        //HSSFWorkbook workbook = excelTool.exportWorkbook(titleData, rowList);
        //excelTool.save(workbook,"C:\\Users\\Administrator\\Desktop\\多级表头Obj.xlsx");
        heads.put("实体类(entity)多级表头表格",titleData);// 每个sheet的表头,sheet名称为key
        datas.put("实体类(entity)多级表头表格",rowList);// 每个sheet的内容,sheet名称为key
        types.put("实体类(entity)多级表头表格",0);// 每个sheet的样式类型,sheet名称为key
    }

    public static void 多级表头Obj1() throws Exception {
        List<TitleEntity> titleList = new ArrayList<>();
        titleList.add(new TitleEntity("title", null, "这里是title", null,20));
        titleList.add(new TitleEntity("一级1", "title", "一级1", null,20));
        titleList.add(new TitleEntity("一级2", "title", "一级2", null,20));
        titleList.add(new TitleEntity("二级1", "一级1", "二级1", null,20));
        titleList.add(new TitleEntity("二级2", "一级2", "二级2", null,20));
        titleList.add(new TitleEntity("三级1", "二级1", "三级1", null,20));
        titleList.add(new TitleEntity("三级2", "二级2", "三级2", null,20));
        titleList.add(new TitleEntity("四级1", "三级1", "四级1", "fieldName1",20));
        titleList.add(new TitleEntity("四级2", "三级1", "四级2", "fieldName2",20));
        titleList.add(new TitleEntity("四级3", "三级2", "四级3", "fieldName3",20));
        titleList.add(new TitleEntity("四级4", "三级2", "四级4", "fieldName4",20));
        //单级的 行内数据
        List<Map<String, String>> rowList = new ArrayList<>();
        for (int i = 0; i < 5; i++) {
            Map<String, String> m = new HashMap<String, String>();
            m.put("fieldName1", "四级1_" + i);
            m.put("fieldName2", "四级2_" + i);
            m.put("fieldName3", "四级3_" + i);
            m.put("fieldName4", "四级4_" + i);
            rowList.add(m);
        }
        ExcelPoiUtil excelTool = new ExcelPoiUtil("实体类(entity)多级表头表格");
        Map<String,String> param = ImmutableMap.<String, String>builder().put("id", "id").put("pid", "pid")
                .put("content", "content").put("fieldName", "fieldName").put("width", "width").build();
        List<ColEntity> titleData = excelTool.colEntityTransformer(titleList, param, "title");
        //HSSFWorkbook workbook = excelTool.exportWorkbook(titleData, rowList);
        //excelTool.save(workbook,"C:\\Users\\Administrator\\Desktop\\多级表头Obj1.xlsx");
        heads.put("实体类(entity)多级表头表格1",titleData);// 每个sheet的表头,sheet名称为key
        datas.put("实体类(entity)多级表头表格1",rowList);// 每个sheet的内容,sheet名称为key
        types.put("实体类(entity)多级表头表格1",0);// 每个sheet的样式类型,sheet名称为key
    }

    public static void 多级表头Obj2() throws Exception {
        List<TitleEntity> titleList = new ArrayList<>();
        titleList.add(new TitleEntity("title", null, "这里是title", null,20));
        // 固定的五项表头
        titleList.add(new TitleEntity("项目", "title", "项目", null,20));
        titleList.add(new TitleEntity("评分规则", "项目", "评分规则", null,20));
        titleList.add(new TitleEntity("评分标准", "评分规则", "评分标准", null,20));
        titleList.add(new TitleEntity("所在单位", "评分标准", "所在单位", "unit",15));
        titleList.add(new TitleEntity("所在部门", "评分标准", "所在部门", "dept",15));
        // 动态表头(实际项目需要根据数据库数据添加)
        int count = 0;
        for (int i = 0; i < 2; i++) {
            String xmId = "项目"+(i+1);
            TitleEntity xm = new TitleEntity(xmId, "title", xmId, null, 20);
            titleList.add(xm);
            for (int j = 0; j < 2; j++) {
                String gzId = "项目"+(i+1)+"-"+"规则"+(j+1);
                String bzId = "项目"+(i+1)+"-"+"标准"+(j+1);
                TitleEntity gz = new TitleEntity(gzId, xmId, gzId, null, 20);
                TitleEntity bz = new TitleEntity(bzId, gzId, String.valueOf(j), null, 20);
                TitleEntity sl = new TitleEntity(bzId+"_sl"+j, bzId, "数量", "sl"+count, 10);
                TitleEntity df = new TitleEntity(bzId+"_df"+j, bzId, "得分", "df"+count, 10);
                titleList.add(gz);
                titleList.add(bz);
                titleList.add(sl);
                titleList.add(df);
                count++;
            }
        }
        // 填充数据
        List<Map<String, String>> rowList = new ArrayList<>();
        for (int i = 0; i < 6; i++) {
            Map<String, String> m = new HashMap<String, String>();
            if (i<4){
                m.put("unit", "A单位");
                m.put("dept", "部门" + i);
            }else {
                m.put("unit", "B单位");
                m.put("dept", "部门" + i);
            }
            for (int j = 0; j < count; j++) {
                m.put("sl"+j, String.valueOf(j));
                m.put("df"+j, String.valueOf(j+i));
            }
            rowList.add(m);
        }
        ExcelPoiUtil excelTool = new ExcelPoiUtil("实体类(entity)多级表头表格");
        Map<String,String> param = ImmutableMap.<String, String>builder().put("id", "id").put("pid", "pid")
                .put("content", "content").put("fieldName", "fieldName").put("width", "width").build();
        List<ColEntity> titleData = excelTool.colEntityTransformer(titleList, param, "title");
        //HSSFWorkbook workbook = excelTool.exportWorkbook(titleData, rowList,Arrays.asList(0));
        //excelTool.save(workbook,"C:\\Users\\Administrator\\Desktop\\多级表头Obj2.xlsx");
        heads.put("实体类(entity)多级表头表格2",titleData);// 每个sheet的表头,sheet名称为key
        datas.put("实体类(entity)多级表头表格2",rowList);// 每个sheet的内容,sheet名称为key
        types.put("实体类(entity)多级表头表格2",0);// 每个sheet的样式类型,sheet名称为key
        mergeIndexs.put("实体类(entity)多级表头表格2",Arrays.asList(0));// 每个sheet的默认行高,sheet名称为key
    }

    public static void 纵向合并单元格() throws Exception {
        List<Map<String,String>> titleList=new ArrayList<>();
        Map<String,String> titleMap=new HashMap<String,String>();
        titleMap.put("id","11");titleMap.put("pid","0");titleMap.put("content","登录名");titleMap.put("fieldName","u_login_id");titleMap.put("width","20");
        Map<String,String> titleMap1=new HashMap<String,String>();
        titleMap1.put("id","1");titleMap1.put("pid","0");titleMap1.put("content","姓名");titleMap1.put("fieldName","u_name");titleMap1.put("width","20");
        Map<String,String> titleMap2=new HashMap<String,String>();
        titleMap2.put("id","2");titleMap2.put("pid","0");titleMap2.put("content","角色加部门");titleMap2.put("fieldName",null);titleMap2.put("width","20");
        Map<String,String> titleMap3=new HashMap<String,String>();
        titleMap3.put("id","3");titleMap3.put("pid","2");titleMap3.put("content","角色");titleMap3.put("fieldName","u_role");titleMap3.put("width","15");
        Map<String,String> titleMap4=new HashMap<String,String>();
        titleMap4.put("id","4");titleMap4.put("pid","2");titleMap4.put("content","部门");titleMap4.put("fieldName","u_dep");titleMap4.put("width","15");
        Map<String,String> titleMap5=new HashMap<String,String>();
        titleMap5.put("id","22");titleMap5.put("pid","0");titleMap5.put("content","角色加部门1");titleMap5.put("fieldName",null);titleMap5.put("width","20");
        Map<String,String> titleMap6=new HashMap<String,String>();
        titleMap6.put("id","22_1");titleMap6.put("pid","22");titleMap6.put("content","角色1");titleMap6.put("fieldName","u_role");titleMap6.put("width","10");
        Map<String,String> titleMap7=new HashMap<String,String>();
        titleMap7.put("id","22_2");titleMap7.put("pid","22");titleMap7.put("content","部门1");titleMap7.put("fieldName","u_dep");titleMap7.put("width","10");
        titleList.add(titleMap); titleList.add(titleMap1); titleList.add(titleMap2); titleList.add(titleMap3); titleList.add(titleMap4);
        titleList.add(titleMap5); titleList.add(titleMap6); titleList.add(titleMap7);
        // 单级的 行内数据
        List<Map<String, String>> rowList = new ArrayList<>();
        for (int i = 0; i < 10; i++) {
            Map<String, String> m = new HashMap<String, String>();
            if (i == 0){
                m.put("u_login_id", "登录名zx1");
                m.put("u_name", "张三1");
            }else if (i >0 && i < 3){
                m.put("u_login_id", "登录名zx2");
                m.put("u_name", "张三2");
            }else if (i == 3){
                m.put("u_login_id", "登录名zx1");
                m.put("u_name", "李四1");
            }else if (i > 3 && i < 7){
                m.put("u_login_id", "登录名zx1");
                m.put("u_name", i == 6 ? "张三2" : "张三1");
            }else if (i > 6){
                m.put("u_login_id", "登录名zx2");
                m.put("u_name", "李四1");
            }
            m.put("u_role", "角色" + i);
            m.put("u_dep", "部门" + i);
            m.put("u_type", "用户类型" + i);
            rowList.add(m);
        }
        ExcelPoiUtil excelTool = new ExcelPoiUtil("纵向合并单元格");
        Map<String,String> param = ImmutableMap.<String, String>builder().put("id", "id").put("pid", "pid")
                .put("content", "content").put("fieldName", "fieldName").put("width", "width").build();
        List<ColEntity> titleData = excelTool.colEntityTransformer(titleList,param, "0");
        //HSSFWorkbook workbook = excelTool.exportWorkbook(titleData, rowList,Arrays.asList(0,1));
        //excelTool.save(workbook,"C:\\Users\\Administrator\\Desktop\\纵向合并单元格.xlsx");
        heads.put("纵向合并单元格",titleData);// 每个sheet的表头,sheet名称为key
        datas.put("纵向合并单元格",rowList);// 每个sheet的内容,sheet名称为key
        types.put("纵向合并单元格",0);// 每个sheet的样式类型,sheet名称为key
        mergeIndexs.put("纵向合并单元格",Arrays.asList(0,1));// 每个sheet的默认行高,sheet名称为key
    }
}

最后

以上,终于是把项目里要的表格给导出来了!😎

实现代码的结构如图:

在这里插入图片描述

源码在这

最后感谢 这篇文章 的作者,也感谢这文章评论区提出bug的用户🥰

希望大家多多点赞支持一下,大家不要光收藏不点赞啊呜呜呜,然后去下载源码的时候也顺便给博主点个Star呀~

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