使用com.alibaba.fastjson.JSONObject构造一个简单的JSON数据，构造的数据类似于：

{
    "data": {
        "jfhf": "fff",
        "otherData": [
            {
                "f445": "fff",
                "f44": "fff",
                "f12": "fff"
            }
        ],
        "userData": {
            "ff": "fff",
            "f1f": "fff",
            "f2f": "fff"
        },
        "jf43hf": "ggg",
        "jfh4f": "ggg"
    },
    "userName": "lin",
    "password": "lin123"
}

代码如下：

    package com.test;

    import java.util.ArrayList;
    import java.util.HashMap;
    import java.util.List;
    import java.util.Map;
    import com.alibaba.fastjson.JSONObject;

    public static void main(String[] args)
    {
        Map<String, String> param1 = new HashMap<String,String>();
        String userName = "lin";
        String password= "lin123";
        param1.put("userName", userName);
        param1.put("password", password);
        Map<String,Object> param2 = new HashMap<String,Object>();
        param2.put("jf43hf","ggg");
        param2.put("jfhf","fff");
        param2.put("jfh4f","ggg");

        Map<String,String> param3 = new HashMap<String,String>();
        param3.put("ff", "fff");
        param3.put("f1f", "fff");
        param3.put("f2f", "fff");
        param2.put("userData", param3);


        Map<String,String> param4 = new HashMap<String,String>();
        List<Map<String,String>> list = new ArrayList<Map<String,String>>();
        List<Map<String,String>> list1 = new ArrayList<Map<String,String>>();
        list1.add(param3);
        for(Map<String,String> m : list1){
            param4.put("f12", "fff");
            param4.put("f445", "fff");
            param4.put("f44", "fff");
            list.add(param4);
        }


        param2.put("otherData", list);

        JSONObject jsonObject1 = new JSONObject();
        jsonObject1.put("data", param2);

        JSONObject jsonThree = new JSONObject(); 
        jsonThree.putAll(param1);
        jsonThree.putAll(jsonObject1);

        System.out.println(jsonThree.toString());

    }

第一层就简单的包含{“userName”:”lin”,”password”:”lin123”}，第二层就为data层，即为代码中的param2集合，param2这个集合放置另一列表和另一集合，并且构造出需要的json数据，大家看代码理解吧，应该挺容易的！