JSON字符串转换JAVA对象例子。

JsonTest:

package com.demo.json;

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

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

import org.json.simple.JSONValue;

public class JsonTest
{
    public static void main(String[] args)
    {
        // -----------------------------------------------------------------------------
        // Object 2 JSON
        List<Peoper> peopers = new ArrayList<Peoper>();
        Peoper p1 = new Peoper("001", "Taki", "中国");
        Peoper p2 = new Peoper("002", "DSM", "China");
        peopers.add(p1);
        peopers.add(p2);
        String result = JsonTool.getJsonString("Peopers", peopers);
        System.out.println("JSON: " + result);

        // 解析PHP json_encode 字符串
        String jsonStr = "{\"Name\":\"\u5e0c\u4e9a\",\"Age\":20}";
        Object obj = JSONValue.parse(jsonStr);
        System.out.println(obj);
        System.out.println();

        // -----------------------------------------------------------------------------
        // JSON 2 Object
        String jsonString = "["
                + "{\"author\":\"7\",\"id\":358,\"title\":\"Japan\",\"pictures\":[{\"description\":\"001\",\"imgPath\":\"/cms/u/cms/www/201203/05150720ii68.jpg\"},{\"description\":\"002\",\"imgPath\":\"/cms/u/cms/www/201203/05150720ii67.jpg\"}],\"path\":\"ip\"},"
                + "{\"author\":\"8\",\"id\":359,\"title\":\"China\",\"pictures\":[{\"description\":\"101\",\"imgPath\":\"/cms/u/cms/www/201203/111111111111.jpg\"},{\"description\":\"102\",\"imgPath\":\"/cms/u/cms/www/201203/222222222222.jpg\"}],\"path\":\"ip\"}]";
        JSONArray array = JSONArray.fromObject(jsonString);

        // Content.class包含pictures.class,需要设置这个参数
        Map<String, Class<pictures>> classMap = new HashMap<String, Class<pictures>>();
        classMap.put("pictures", pictures.class);

        Object[] objs = new Object[array.size()];
        for (int i = 0; i < array.size(); i++)
        {
            JSONObject jsonObject = array.getJSONObject(i);
            objs[i] = (Content) JSONObject.toBean(jsonObject, Content.class, classMap);
        }
        // 转换Content,循环输出所有content
        for (int i = 0; i < objs.length; i++)
        {
            Content content = (Content) objs[i];
            System.out.println("author:" + content.getAuthor() + " ID:"
                    + content.getId() + " Title:" + content.getTitle() + " Path:" + content.getPath());

            // 转换pictures,循环输出所有picture
            List<pictures> pictures = content.getPictures();
            for (int n = 0; n < pictures.size(); n++)
                System.out.println("description:"
                        + pictures.get(n).getDescription() + " imgPath:" + pictures.get(n).getImgPath());
        }
    }
}

JsonTool:

package com.demo.json;

import java.util.regex.Matcher;
import java.util.regex.Pattern;

import net.sf.json.JSONObject;


public class JsonTool 
{
	public static String getJsonString(Object key, Object value)
	{
		//System.out.println("key: " + key);
		//System.out.println("value: " + value.toString());
		JSONObject obj = new JSONObject();
		obj.put(key, value);	//添加物件
		return obj.toString();	//转换为字符串并返回
	}
	
	//解析PHP json_encode 字符串
	public static String unescapeUnicode(String str)
	{
        StringBuffer b=new StringBuffer();
        Matcher m = Pattern.compile("\\\\u([0-9a-fA-F]{4})").matcher(str);
        while(m.find())
        {
            b.append((char)Integer.parseInt(m.group(1),16));
        }
        return b.toString();
    }
}

People:

package com.demo.json;

public class People 
{
	public People() 
	{				
	}
	
	public People(String id, String name, String address) 
	{		
		this.id = id;
		this.name = name;
		this.address = address;
	}

	private String id;
	private String name;
	private String address;
	
	public String getId() {
		return id;
	}

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

	public String getName() {
		return name;
	}

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

	public String getAddress() {
		return address;
	}

	public void setAddress(String address) {
		this.address = address;
	}
	
	public String toString()
	{
		return "ID:" + this.id + " Name:" + this.name + " Address:" + this.address;
	}
}

Content:

package com.demo.json;

import java.util.List;

public class Content {
	
	private String author;
	private String id;
	private String title;
	private List<pictures> pictures;
	private String path;

	public String getAuthor() {
		return author;
	}

	public void setAuthor(String author) {
		this.author = author;
	}

	public String getId() {
		return id;
	}

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

	public String getTitle() {
		return title;
	}

	public void setTitle(String title) {
		this.title = title;
	}

	public List<pictures> getPictures() {
		return pictures;
	}

	public void setPictures(List<pictures> pictures) {
		this.pictures = pictures;
	}

	public String getPath() {
		return path;
	}

	public void setPath(String path) {
		this.path = path;
	}
}

pictures:

package com.demo.json;

public class pictures {
	private String description;
	private String imgPath;

	public String getDescription() {
		return description;
	}

	public void setDescription(String description) {
		this.description = description;
	}

	public String getImgPath() {
		return imgPath;
	}

	public void setImgPath(String imgPath) {
		this.imgPath = imgPath;
	}
}

 控制台运行结果：

JSON: {"Peopers":[{"address":"中国","id":"001","name":"Taki"},{"address":"China","id":"002","name":"DSM"}]}
{"Name":"中文内容","Age":20}

author:7 ID:358 Title:Japan Path:ip
description:001 imgPath:/cms/u/cms/www/201203/05150720ii68.jpg
description:002 imgPath:/cms/u/cms/www/201203/05150720ii67.jpg
author:8 ID:359 Title:China Path:ip
description:101 imgPath:/cms/u/cms/www/201203/111111111111.jpg
description:102 imgPath:/cms/u/cms/www/201203/222222222222.jpg