java对象与JSON字符串互转jar,及其用法

一、json-lib示例

package net.pink.test;

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;

public class Main2 {

	/**
	 * @param args
	 */
	public static void main(String[] args) {
		// object to json
		// jsonObject
		Map<String, Object> map = new HashMap<String, Object>();
		User user = new User("pink", 34);
		User user2 = new User("pink2", 44);
		User user3 = new User("pink3", 22);
		map.put("user", user);
		map.put("user2", user2);
		map.put("user3", user3);
		JSONObject jObject = JSONObject.fromObject(map);
		// jObject.toString() json字符串
		System.out.println(jObject.toString());
		// jsonArray
		List<String> list = new ArrayList<String>();
		list.add("php");
		list.add("java");
		list.add("c++");
		list.add("perl");
		list.add("python");
		JSONArray jsArray = JSONArray.fromObject(list);
		// jsArray.toString() json字符串
		System.out.println(jsArray.toString());

		// json to object
		// jsonObject
		JSONObject jObject2 = JSONObject.fromObject(jObject.toString());
		jObject2.getJSONObject("user");
		JSONObject jObject3 = jObject2.getJSONObject("user");
		String username = jObject3.getString("username");
		System.out.println(username);
		// jsonArray
		JSONArray jsArray2 = JSONArray.fromObject(jsArray.toArray());
		String lang = jsArray2.getString(1);
		System.out.println(lang);
	}

	public static class User {
		private String username;

		private int age;

		public User(String username, int age) {
			super();
			this.username = username;
			this.age = age;
		}

		public int getAge() {
			return age;
		}

		public void setAge(int age) {
			this.age = age;
		}

		public String getUsername() {
			return username;
		}

		public void setUsername(String username) {
			this.username = username;
		}
	}
}

二、org.json示例

package net.pink.test;

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

import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;

public class Main {

	/**
	 * @param args
	 */
	public static void main(String[] args) {
		// object to json
		// jsonObject
		Map<String, Object> map = new HashMap<String, Object>();
		User user = new User("pink", 34);
		User user2 = new User("pink2", 44);
		User user3 = new User("pink3", 22);
		map.put("user", user);
		map.put("user2", user2);
		map.put("user3", user3);
		JSONObject jObject = new JSONObject(map);
		System.out.println(jObject);
		// josnArray
		List<String> list = new ArrayList<String>();
		list.add("php");
		list.add("java");
		list.add("c++");
		list.add("perl");
		list.add("python");
		JSONArray jsArray = new JSONArray(list);
		System.out.println(jsArray);

		// json to object
		try {
			// jsonObject
			JSONObject jObject2 = new JSONObject(jObject.toString());
			JSONObject jObject3 = jObject2.getJSONObject("user");
			String username = jObject3.getString("username");
			System.out.println(username);
			// jsonArray
			JSONArray jsArray2 = new JSONArray(jsArray.toString());
		    String lang = jsArray2.getString(1);
		    System.out.println(lang);
		} catch (JSONException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
	}

	public static class User {
		private String username;

		private int age;

		public User(String username, int age) {
			super();
			this.username = username;
			this.age = age;
		}

		public int getAge() {
			return age;
		}

		public void setAge(int age) {
			this.age = age;
		}

		public String getUsername() {
			return username;
		}

		public void setUsername(String username) {
			this.username = username;
		}
	}

}