使用第三方工具，将JavaBean对象或者List<JavaBean/String/Integer>或Set或Map对象转成JSON

准备导入第三方jar包：

》commons-beanutils-1.7.0.jar

》commons-collections-3.1.jar

》commons-lang-2.5.jar

》commons-logging-1.1.1.jar

》ezmorph-1.0.3.jar

》json-lib-2.1-jdk15.jar

User.java

package com.itcast.android;

public class User {

private Integer id;
private String name;
private String gener;

public User() {

}

public User(Integer id, String name, String gener) {
super();
this.id = id;
this.name = name;
this.gener = gener;
}

public Integer getId() {
return id;
}

public void setId(Integer id) {
this.id = id;
}

public String getName() {
return name;
}

public void setName(String name) {
this.name = name;
}

public String getGener() {
return gener;
}

public void setGener(String gener) {
this.gener = gener;
}

}

Bean2Json.java

package com.itcast.android;

import java.util.ArrayList;
import java.util.LinkedHashMap;
import java.util.List;
import java.util.Map;

import net.sf.json.JSONArray;

/**
* 使用第三方工具类,将Bean转化为JSON文本
*
* @author ZXY
*
*/
public class Bean2Json {

// Bean转化JSON
public void bean2jsion() {
User user = new User(1, "笨笨", "男");
// 将User对象转化为JSON文本
JSONArray jsonArray = JSONArray.fromObject(user);
// 获取JSON文本
String json = jsonArray.toString();
// 输出控制台显示
System.out.println(json);
// [{"gener":"男","id":1,"name":"笨笨"}]

}

// List<Bean>转化JSON
public void list2jsion() {
List<User> userList = new ArrayList<User>();
userList.add(new User(1, "张飞", "男"));
userList.add(new User(2, "刘备", "男"));
userList.add(new User(3, "关羽", "男"));
JSONArray jsonArray = JSONArray.fromObject(userList);
String json = jsonArray.toString();
System.out.println(json);
// [{"gener":"男","id":1,"name":"张飞"},{"gener":"男","id":2,"name":"刘备"},{"gener":"男","id":3,"name":"关羽"}]

}

// Map<String,Object>转化JSON
public void map2json() {
List<User> userList = new ArrayList<User>();
userList.add(new User(1, "张飞", "男"));
userList.add(new User(2, "刘备", "男"));
userList.add(new User(3, "关羽", "男"));
userList.add(new User(4, "小乔", "女"));

Map<String, Object> map = new LinkedHashMap<String, Object>();
//存放集合的长度
map.put("size", userList.size());
//存放整个集合
map.put("list", userList);
//通过第三方工具将Map转化为JSon文本
JSONArray jsonArray = JSONArray.fromObject(map);
String json = jsonArray.toString();
System.out.println(json);
//[{"size":4,"list":[{"gener":"男","id":1,"name":"张飞"},{"gener":"男","id":2,"name":"刘备"},{"gener":"男","id":3,"name":"关羽"},{"gener":"女","id":4,"name":"小乔"}]}]
//通过如下代码将最外面[]去掉
json=json.substring(1,json.length()-1);
System.out.println(json);
//{"size":4,"list":[{"gener":"男","id":1,"name":"张飞"},{"gener":"男","id":2,"name":"刘备"},{"gener":"男","id":3,"name":"关羽"},{"gener":"女","id":4,"name":"小乔"}]}

}

public static void main(String[] args) {

Bean2Json test = new Bean2Json();

test.bean2jsion();
test.list2jsion();
test.map2json();
}

}