java 从json串中取出某个字段的值

package com.cmbc.cms.action.addrebatchno;

import java.util.List;

import com.alibaba.fastjson.JSONObject;

public class Test {

public int getId() {

return id;

}

public void setId(int id) {

this.id = id;

}

public int getNum() {

return num;

}

public void setNum(int num) {

this.num = num;

}

private int id;

private int num;

public static void main(String[] args) {

// TODO Auto-generated method stub

String str = "{\"id\":\"75\",\"shoppingCartItemList\":[{\"id\":\"407\",\"num\":\"10\"}]}";

JSONObject jsonObject = JSONObject.parseObject(str);

// 获取到key为shoppingCartItemList的值

String r = jsonObject.getString( "shoppingCartItemList");

System.out.println(r);

//取外面的id

String id = jsonObject.getString( "id");

System.out.println(id);

//取里面的id

List<Test> list = JSONObject.parseArray(r,Test.class);

int id2 = list.get(0).getId();

System.out.println(id2);

}

}