示例如下：

将红框列的 + 号 - 号转成字符串

实现：

1、先创建一个转换类并实现Converter 接口，转换类内容如下：

import com.alibaba.excel.converters.Converter;
import com.alibaba.excel.enums.CellDataTypeEnum;
import com.alibaba.excel.metadata.CellData;
import com.alibaba.excel.metadata.GlobalConfiguration;
import com.alibaba.excel.metadata.property.ExcelContentProperty;

public class AddOrDelConverter implements Converter<String> {
    @Override
    public Class supportJavaTypeKey() {
        return null;
    }

    @Override
    public CellDataTypeEnum supportExcelTypeKey() {
        return null;
    }

    @Override
    public String convertToJavaData(CellData cellData, ExcelContentProperty contentProperty, GlobalConfiguration globalConfiguration) throws Exception {
        return null;
    }

    @Override
    public CellData convertToExcelData(String value, ExcelContentProperty contentProperty, GlobalConfiguration globalConfiguration) throws Exception {
        return null;
    }
}

2、在convertToExcelData()方法里面写将数据库字段转换成EXCEL显示字段的逻辑，例如：

​
 @Override
    public CellData convertToExcelData(String value, ExcelContentProperty contentProperty, GlobalConfiguration globalConfiguration) throws Exception {
        if( value == "+" ){
            return new CellData("添加");
        }else {
            return new CellData("删除");
        }

    }

​

3、然后在实体类上使用：

	@TableField("add_or_del")
	@ExcelProperty(value = "添加或删除",converter = AddOrDelConverter.class)
	private java.lang.String addOrDel;

转换后效果如下：