// 声明两个json数组

         JSONArray gResTable = new JSONArray(); 
         JSONArray gCmtTable = new JSONArray(); 
   // 声明json对象		
	JSONObject outData = new JSONObject();
   //把json数组加到json对象中

	outData.put("ResTable", gResTable);
	outData.put("CmtTable", gCmtTable);
   //此时创建出来的如下:jsonData={"ResTable":[],"CmtTable":[]};
   把json数据加到json数组中
	for (int i = 0; i < 2; i ++)
	{
		JSONObject node = new JSONObject();
		node.put("thumb_path", "./Image/" + i +".gif");
		node.put("flash_path", "./Image/" + i +".gif");
		node.put("desc1", "可疑车辆" + i);
		node.put("desc2", "");
		node.put("desc3", "");
		node.put("desc4", "");
		node.put("title", "hello");
		node.put("upload_time", (new java.util.Date()).toString());
		node.put("uploader", "王二");
		gResTable.put(node);
	}
	
	for (int i = 0; i < 2; i ++)
	{
		JSONObject node = new JSONObject();
		node.put("logo_path", "./Image/" + i +".gif");
		node.put("comment", "hello");
		node.put("comment_time", (new java.util.Date()).toString());
		node.put("author", "王二");
		gCmtTable.put(node);
	}
创建出来的json格式如下：

/*
    jsonData={"ResTable":[
	{"upload_time":"Sat May 26 20:16:37 CST 2012","title":"hello","flash_path":"./Image/0.gif","uploader":"王二","thumb_path":"./Image/0.gif","desc3":"","desc4":"","desc1":"可疑车辆0","desc2":""},
	{"upload_time":"Sat May 26 20:16:37 CST 2012","title":"hello","flash_path":"./Image/1.gif","uploader":"王二","thumb_path":"./Image/1.gif","desc3":"","desc4":"","desc1":"可疑车辆1","desc2":""}],
    "CmtTable":
	[{"author":"王二","logo_path":"./Image/0.gif","comment":"hello","comment_time":"Sat May 26 20:16:37 CST 2012"},
	{"author":"王二","logo_path":"./Image/1.gif","comment":"hello","comment_time":"Sat May 26 20:16:37 CST 2012"}
 ]};
*/

我们在写通用方法时，往往通过反射来创建对象。在有时候我们将动态对象转成JSON。需要将另外动态对象插入到JSON中时。就需要如下操作：

工作中，将亚马逊接口通用化的时候。需要将订单明细B 加入到订单主体A中。并且自定义属性AmazonOrderDetail。

正常的操作是新建对象 C 将属性分别赋值就行了。

但是我是通用接口。只知道SDK中的ClassName.

于是就有了下面的操作。

直接上代码：

//对象A               
Object currentObj;

                
JSONArray jsonArrayInput = new JSONArray();

                
JSONObject jsonObject = JSON.parseObject(JSON.toJSONString(currentObj));


//对象B 类名            
String childClassName = "";

  
jsonArrayInput.addAll(JSON.parseArray("对象B的JSON串", Class.forName(childClassName)));
                jsonObject.put("AmazonOrderDetail", jsonArrayInput);

附加在JSon中获取所有键值：

import com.alibaba.fastjson.JSON;
import com.alibaba.fastjson.JSONArray;
import com.alibaba.fastjson.JSONObject;
import org.springframework.stereotype.Component;

import java.io.IOException;
import java.util.*;

/**
 * @Author: yanjing
 * @Date: 2019-04-18
 */
@Component
public class JsonToMapUtil {

    private void JsonToMap(Stack<JSONObject> stObj, Map<String, Object> resultMap) throws IOException {

        if (stObj == null && stObj.pop() == null) {
            return;
        }
        JSONObject json = stObj.pop();
        Set<String> keySet = json.keySet();
        for (String key : keySet) {
            Object value = json.get(key);
            if (value instanceof JSONObject) {
                stObj.push((JSONObject) value);
                // 递归遍历
                JsonToMap(stObj, resultMap);
            } else if (value instanceof JSONArray) {
                for (Object err : (JSONArray) value) {
                    if (err instanceof JSONObject) {
                        JSONObject errItem = (JSONObject) err;
                        stObj.push(errItem);
                        JsonToMap(stObj, resultMap);
                    } else {
                        resultMap.put(key, value);
                    }
                }
            } else {
                resultMap.put(key, value);
            }
        }
    }

    public Object getValue(String jsonStr, String attrName) {
        try {
            JSONObject obj = JSON.parseObject(jsonStr);
            Stack<JSONObject> stObj = new Stack<JSONObject>();
            stObj.push(obj);
            Map<String, Object> resultMap = new HashMap<String, Object>();
            this.JsonToMap(stObj, resultMap);
            Set<String> keys = resultMap.keySet();
            for (String key : keys) {
                if (attrName.toLowerCase().equals(key.toLowerCase())) {
                    return resultMap.get(key);
                }
            }
        } catch (IOException e) {
            e.printStackTrace();
        }
        return null;
    }

}