JSONObject的toBean 和 fromObject

public static void main(String[] args) {
Map map=new HashMap();
map.put("1","a");
map.put("2","b");
map.put("3","c");
JSONObject json = JSONObject.fromObject(map);
System.out.println(json);
}

輸出的結果 {"1":"a","2":"b","3":"c"}

toBean();

首先一个javabean对象
public class Student {

private int id ;
private String name;
private int age;

public int getId() {
return id;
}
public void setId(int id) {
this.id = id;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public int getAge() {
return age;
}
public void setAge(int age) {
this.age = age;
}

public String toString(){
return this.id + ", " + this.name + ", " + this.age;
}
}

然后测试toBean方法的类
import net.sf.json.JSONObject;

public class ToBeanTest {

public static void main(String[] args) {

String json = "{id:'1001',name:'张三',age:'22'}";
Student stu = new Student();
JSONObject obj = JSONObject.fromObject(json);
stu = (Student)JSONObject.toBean(obj, Student.class);
System.out.println(stu);
}

}
输出结果为1001, 张三, 22
然后我们在修改修改
import net.sf.json.JSONObject;

public class ToBeanTest {

public static void main(String[] args) {

String json = "{id:'1001',name:'张三'}";
Student stu = new Student();
JSONObject obj = JSONObject.fromObject(json);
stu = (Student)JSONObject.toBean(obj, Student.class);
System.out.println(stu);
}

}
把年龄给去掉age为int型，输出结果为：1001, 张三, 0
然后再做小小改动
import net.sf.json.JSONObject;

public class ToBeanTest {

public static void main(String[] args) {

String json = "{id:'1001',age:'22'}";
Student stu = new Student();
JSONObject obj = JSONObject.fromObject(json);
stu = (Student)JSONObject.toBean(obj, Student.class);
System.out.println(stu);
}

}
把姓名给去掉name为String型，输出结果为：1001, null, 22
再改动一下：
import net.sf.json.JSONObject;

public class ToBeanTest {

public static void main(String[] args) {

String json = "{id:'1001',name:'张三',age:'nn'}";
Student stu = new Student();
JSONObject obj = JSONObject.fromObject(json);
stu = (Student)JSONObject.toBean(obj, Student.class);
System.out.println(stu);
}

}
把age改成非整形，输出结果为：
1001, 张三, 0

再改动一下：
import net.sf.json.JSONObject;

public class ToBeanTest {

public static void main(String[] args) {

String json = "{id:'1001',name:'张三',age:'22',sex:'男'}";
Student stu = new Student();
JSONObject obj = JSONObject.fromObject(json);
stu = (Student)JSONObject.toBean(obj, Student.class);
System.out.println(stu);
}

}
加了一个sex:'男'的一对键值，输出结果为：
1001, 张三, 22

JSONObject与JSONArray的使用方法

一、JAR包简介

要使程序可以运行必须引入JSON-lib包，JSON-lib包同时依赖于以下的JAR包：

1.commons-lang.jar

2.commons-beanutils.jar

3.commons-collections.jar

4.commons-logging.jar

5.ezmorph.jar

6.json-lib-2.2.2-jdk15.jar

二、JSONObject对象使用

JSON-lib包是一个beans,collections,maps,java arrays 和XML和JSON互相转换的包。在本例中，我们将使用JSONObject类创建JSONObject对象，然后我们打印这些对象的值。为了使用JSONObject对象，我们要引入"net.sf.json"包。为了给对象添加元素，我们要使用put()方法。

package com.tjcyjd;

import net.sf.json.JSONArray;
import net.sf.json.JSONObject;

public class JSONObjectSample {
// 创建JSONObject对象
private static JSONObject createJSONObject() {
JSONObject jsonObject = new JSONObject();
jsonObject.put("username", "yangjinde");
jsonObject.put("sex", "男");
jsonObject.put("QQ", "908599713");
jsonObject.put("yjd.score", new Integer(100));
jsonObject.put("nickname", "搁浅");
return jsonObject;
}

public static void main(String[] args) {
JSONObject jsonObject = JSONObjectSample.createJSONObject();
// 输出jsonobject对象
System.out.println("jsonObject：" + jsonObject);
// 判读输出对象的类型
boolean isArray = jsonObject.isArray();
boolean isEmpty = jsonObject.isEmpty();
boolean isNullObject = jsonObject.isNullObject();
System.out.println("isArray:" + isArray + " isEmpty:" + isEmpty
+ " isNullObject:" + isNullObject);
// 往JSONObject添加属性
jsonObject.element("address", "北京中关村");
System.out.println("添加属性后的对象：" + jsonObject);
// 创建一个JSONArray对象
JSONArray jsonArray = new JSONArray();
jsonArray.add(0, "this is a jsonArray value");
jsonArray.add(1, "this is another jsonArray value");
// 往JSONObject添加JSONArray
jsonObject.element("jsonArray", jsonArray);
JSONArray array = jsonObject.getJSONArray("jsonArray");
System.out.println("array：" + array);
System.out.println("添加JSONArray后的对象：" + jsonObject);
// 根据key返回一个字符串
String username = jsonObject.getString("username");
System.out.println("username：" + username);
// 把字符转换为 JSONObject
String temp = jsonObject.toString();
System.out.println("要转换为JSONObject的字符串为:" + temp);
JSONObject object = JSONObject.fromObject(temp);
// 转换后根据Key返回值
System.out.println("qq：" + object.get("QQ"));
}
}

运行的结果如下：

jsonObject：{"username":"yangjinde","sex":"男","QQ":"908599713","yjd.score":100,"nickname":"搁浅"}
isArray:false isEmpty:false isNullObject:false
添加属性后的对象：{"username":"yangjinde","sex":"男","QQ":"908599713","yjd.score":100,"nickname":"搁浅","address":"北京中关村"}
array：["this is a jsonArray value","this is another jsonArray value"]
添加JSONArray后的对象：{"username":"yangjinde","sex":"男","QQ":"908599713","yjd.score":100,"nickname":"搁浅","address":"北京中关村","jsonArray":["this is a jsonArray value","this is another jsonArray value"]}
username：yangjinde
要转换为JSONObject的字符串为:{"username":"yangjinde","sex":"男","QQ":"908599713","yjd.score":100,"nickname":"搁浅","address":"北京中关村","jsonArray":["this is a jsonArray value","this is another jsonArray value"]}
qq：908599713