fastjson生成和解析json数据



本文讲解2点:

1. fastjson生成和解析json数据

  (举例:4种常用类型:JavaBean,List<JavaBean>,List<String>,List<Map<String,Object>)

2.通过一个android程序测试fastjson的用法。

fastjson简介:

Fastjson是一个Java语言编写的高性能功能完善的JSON库。fastjson采用独创的算法,将parse的速度提升到极致,超过所有json库,包括曾经号称最快的jackson。并且还超越了google的二进制协议protocol buf。Fastjson完全支持http://json.org的标准,也是官方网站收录的参考实现之一。支持各种JDK类型。包括基本类型、JavaBean、Collection、Map、Enum、泛型等。支持JDK 5、JDK 6、Android、阿里云手机等环境。

一. fastjson生成json字符串(JavaBean,List<JavaBean>,List<String>,List<Map<String,Object>)

     String jsonStrng = JSON.toJSONString(object);

二. fastjson 解析json字符串为四种类型

      1. JavaBean

          Person person = JSON.parseObject(jsonString, Person.class);

      2. List<JavaBean>

          List<Person> listPerson =JSON.parseArray(jsonString, Person.class);

      3. List<String>

          List<String> listString = JSON.parseArray(jsonString, String.class);

      4. List<Map<String,Object>>

          List<Map<String, Object>> listMap = JSON.parseObject(jsonString, new TypeReference<List<Map<String,Object>>>(){});  (注意:此处可看出fastjson反射机制比gson更准确, id = 1001 通过fastjson反射仍是 id = 1001 , 而通过gson反射结果 为 id =1001.0 ,参考前篇程序运行结果图GSON方式生成和解析json数据)

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程序运行结果:

1. 点击“解析Person数据”按钮

2. 点击“解析Persons数据按钮”

3.点击“解析listString数据”按钮

4.点击“解析listMap数据”按钮

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客户端eclipse android工程目录(左边)服务器端myeclipse web工程(右边)

   

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服务器端 fastjson_Project

1.FastJsonAction.java

package com.fastjson.action;

import java.io.IOException;
import java.io.PrintWriter;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import com.fastjson.service.FastJsonService;
import com.fastjson.tools.*;

public class FastJsonAction extends HttpServlet {



	/**
	 * Destruction of the servlet. <br>
	 */
	public void destroy() {
		super.destroy(); // Just puts "destroy" string in log
		// Put your code here
	}

	/**
	 * The doGet method of the servlet. <br>
	 *
	 * This method is called when a form has its tag value method equals to get.
	 * 
	 * @param request the request send by the client to the server
	 * @param response the response send by the server to the client
	 * @throws ServletException if an error occurred
	 * @throws IOException if an error occurred
	 */
	public void doGet(HttpServletRequest request, HttpServletResponse response)
			throws ServletException, IOException {
		this.doPost(request, response);
	}

	/**
	 * The doPost method of the servlet. <br>
	 *
	 * This method is called when a form has its tag value method equals to post.
	 * 
	 * @param request the request send by the client to the server
	 * @param response the response send by the server to the client
	 * @throws ServletException if an error occurred
	 * @throws IOException if an error occurred
	 */
	public void doPost(HttpServletRequest request, HttpServletResponse response)
			throws ServletException, IOException {

		response.setContentType("text/html;charset=utf-8");
		request.setCharacterEncoding("utf-8");
		response.setCharacterEncoding("utf-8");
		
		String action_flag = request.getParameter("action_flag");		
		PrintWriter out = response.getWriter();
		if ("person".equals(action_flag)) {
	//		String person = GsonTools.creatJsonString(GsonService.getPerson());
			String person = FastJsonTools.createJsonString(FastJsonService.getPerson());
			out.println(person);
			System.out.println(person);
			
		} else if("persons".equals(action_flag)) {
	//		String persons = GsonTools.creatJsonString(GsonService.getListPersons());
			String persons = FastJsonTools.createJsonString(FastJsonService.getListPersons());
			out.println(persons);
			System.out.println(persons);
		}else if("listString".equals(action_flag)) {
		//	String listString = GsonTools.creatJsonString(GsonService.getListString());
			String listString = FastJsonTools.createJsonString(FastJsonService.getListString());
			out.println(listString);
			System.out.println(listString);
		}else if("listMap".equals(action_flag)) {
		//	String listMap = GsonTools.creatJsonString(GsonService.getListMap());
			String listMap = FastJsonTools.createJsonString(FastJsonService.getListMap());
			out.println(listMap);
			System.out.println(listMap);
		}
		
		System.out.println();
		
		out.flush();
		out.close();
	}

	/**
	 * Initialization of the servlet. <br>
	 *
	 * @throws ServletException if an error occurs
	 */
	public void init() throws ServletException {
		// Put your code here
	}
}

2.FastJsonService.java

package com.fastjson.service;

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

import com.fastjson.data.Person;

public class FastJsonService {

	public static Person getPerson() {

		Person person = new Person(1001, "刘德华", "香港");
		return person;

	}

	public static List<Person> getListPersons() {
		List<Person> persons = new ArrayList<Person>();
		Person person1 = new Person(1001, "刘德华", "香港");
		Person person2 = new Person(1002, "宋慧乔", "韩国");
		persons.add(person1);
		persons.add(person2);
		return persons;

	}
	
	public static List<String> getListString(){
		
		List<String> list = new ArrayList<String>();
		list.add("美国");
		list.add("中国");
		list.add("俄罗斯");	
		
		return list;
	} 

	
	public static List<java.util.Map<String, Object>> getListMap(){
		List<java.util.Map<String, Object>> list = new ArrayList<Map<String,Object>>();
		java.util.Map<String,Object> map1 = new HashMap<String,Object>();
		map1.put("id",1001);
		map1.put("name","刘德华");
		map1.put("address","香港");
		
		java.util.Map<String,Object> map2 = new HashMap<String,Object>();
		map2.put("id",1002);
		map2.put("name","宋慧乔");
		map2.put("address","韩国");
		
		list.add(map1);
		list.add(map2);
		
		return list;
		
	}
}

3.FastJsonTools.java

package com.fastjson.tools;
import  com.alibaba.fastjson.*;

public class FastJsonTools {
	public static String createJsonString(Object object){
		String jsonString = "";
		try {
			jsonString = JSON.toJSONString(object);
		} catch (Exception e) {
			// TODO: handle exception
		}
		
		return jsonString;
	}
}

4.Person.java

package com.fastjson.data;

public class Person {
	private int id;
	private String name;
    private String address;
	
	public Person() {
		// TODO Auto-generated constructor stub
	}

	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 String getAddress() {
		return address;
	}

	public void setAddress(String address) {
		this.address = address;
	}

	public Person(int id, String name, String address) {
		super();
		this.id = id;
		this.name = name;
		this.address = address;
	}

	@Override
	public String toString() {
		return "Person [id=" + id + ", name=" + name + ", address=" + address
				+ "]";
	}
	

}

5. TestFastJson.java

package com.fastjson.test;

import com.fastjson.service.FastJsonService;
import com.fastjson.tools.FastJsonTools;

public class TestFastJson {

	/**
	 * @param args
	 */
	public static void main(String[] args) {
		// TODO Auto-generated method stub

		//Test1 Person 	
		System.out.println("FastJson数据格式测试结果:\n");
		String person = FastJsonTools.createJsonString(FastJsonService.getPerson()); 

		//Test2 persons
		String listPerson =  FastJsonTools.createJsonString(FastJsonService.getListPersons());
		//Test3 listString
		String listString =  FastJsonTools.createJsonString(FastJsonService.getListString()) ;
		//Test 4 listMap
		String listMap = FastJsonTools.createJsonString(FastJsonService.getListMap()) ;
		
		System.out.println("测试结果1:"+person+"\n");
		System.out.println("测试结果2:"+listPerson+"\n");
		System.out.println("测试结果3:"+listString+"\n");
		System.out.println("测试结果4:"+listMap);

	}

}


客户端:android_fastjson

1.MainActivity.java

package com.android.mygson;

import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.Serializable;
import java.net.HttpURLConnection;
import java.net.URL;
import java.util.List;
import java.util.Map;

import com.alibaba.fastjson.JSON;
import com.alibaba.fastjson.TypeReference;
import com.fastjson.tools.FastJsonTools;
import com.gson.data.Person;
import com.gson.http.HttpUtils;
import android.os.Bundle;
import android.os.StrictMode;
import android.annotation.SuppressLint;
import android.app.Activity;
import android.content.Intent;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;



 public class MainActivity extends Activity implements OnClickListener {
	private Button person, persons, listString, listMap;
	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.activity_main);
		closeStrictMode();//关闭严苛模式		
		

		person = (Button) findViewById(R.id.person);
		persons = (Button) findViewById(R.id.persons);
		listString = (Button) findViewById(R.id.listString);
		listMap = (Button) findViewById(R.id.listMap);
		person.setOnClickListener(this);
		persons.setOnClickListener(this);
		listString.setOnClickListener(this);
		listMap.setOnClickListener(this);

	}

	@Override
	public void onClick(View v) {
		// TODO Auto-generated method stub
		
		switch (v.getId()) {
		case R.id.person:

			String url_path = "http://192.168.0.102:8080/fastjson_Project/servlet/FastJsonAction?action_flag=person";
			String jsonString = HttpUtils.getJsonContent(url_path, "utf-8");				
			Person person = FastJsonTools.getPerson(jsonString, Person.class);
			//用fastJson技术解析json字符串,转换为Person对象
	//		Person person = JSON.parseObject(jsonString, Person.class);
			
		
			
			Intent intent = new Intent(MainActivity.this, OtherActivity.class);
			intent.putExtra("click_flag", "person");
			intent.putExtra("person", (Serializable) person);		
			startActivity(intent);
			
			// Log.i(TAG, person.toString());

			break;

		case R.id.persons:
			String url_path2 = "http://192.168.0.102:8080/fastjson_Project/servlet/FastJsonAction?action_flag=persons";
			String jsonString2 = HttpUtils.getJsonContent(url_path2, "utf-8");			
			
			// 用fastjson 将json字符串转换成 List<Person>
	//		List<Person> listPerson =JSON.parseArray(jsonString2, Person.class);
			List<Person> listPerson =FastJsonTools.getPersons(jsonString2, Person.class);
			Intent intent2 = new Intent(MainActivity.this, OtherActivity.class);
			intent2.putExtra("click_flag", "persons");
			intent2.putExtra("persons", (Serializable) listPerson); // 用Intent传递 List<Person>数据类型
			startActivity(intent2);
			break;
			
		case R.id.listString:
			String url_path3 = "http://192.168.0.102:8080/fastjson_Project/servlet/FastJsonAction?action_flag=listString";
			String jsonString3 = HttpUtils.getJsonContent(url_path3, "utf-8");
			
			// 用fastjson 将json字符串转换成 List<String>
	//		List<String> listString = JSON.parseArray(jsonString3, String.class);
			List<String> listString = FastJsonTools.getPersons(jsonString3,String.class);
			Intent intent3 = new Intent(MainActivity.this, OtherActivity.class);
			intent3.putExtra("click_flag", "listString");
			intent3.putExtra("listString", (Serializable) listString); // 用Intent传递 List<Person>数据类型
			startActivity(intent3);
			break;
			
		case R.id.listMap:
			String url_path4 = "http://192.168.0.102:8080/fastjson_Project/servlet/FastJsonAction?action_flag=listMap";
			String jsonString4 = HttpUtils.getJsonContent(url_path4, "utf-8");
			
			// 用fastjson 将json字符串转换成 List<Map<String,Object>>		
		//	List<Map<String, Object>> listMap = JSON.parseObject(jsonString4, new TypeReference<List<Map<String,Object>>>(){});
			List<Map<String, Object>> listMap = FastJsonTools.getListMap(jsonString4);
			Intent intent4 = new Intent(MainActivity.this, OtherActivity.class);
			intent4.putExtra("click_flag", "listMap");
			intent4.putExtra("listMap", (Serializable) listMap); // 用Intent传递 List<Map<Sting,Object>>数据类型
			intent4.putExtra("jsonString", jsonString4);
			startActivity(intent4);
			break;
			

		}

	}

	@SuppressLint("NewApi")
	public static void closeStrictMode() {
		StrictMode.setThreadPolicy(new StrictMode.ThreadPolicy.Builder()
				.detectAll().penaltyLog().build());
	}
	
	private static String changeInputStream(InputStream inputStream , String encode) throws IOException {
		// TODO Auto-generated method stub
		String  jsonString = null;
		
		ByteArrayOutputStream outputStream = new ByteArrayOutputStream();
		byte[] data = new byte[1024];
		int len = 0;
		while((len=inputStream.read(data))!=-1){
			outputStream.write(data, 0, len);
		}
		
		jsonString = new String(outputStream.toByteArray(), encode);

		inputStream.close();
		
		
		return jsonString;
	}

}

2.OtherActivity.java

package com.android.mygson;


import java.util.List;
import java.util.Map;

import com.gson.data.Person;

import android.R.integer;
import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.widget.TextView;

public class OtherActivity extends Activity {

	private TextView textView;
	@Override
	protected void onCreate(Bundle savedInstanceState) {
		// TODO Auto-generated method stub
		super.onCreate(savedInstanceState);
		setContentView(R.layout.activity_other);

		textView = (TextView) findViewById(R.id.msg);
		Intent intent = getIntent();
		String click_flag = intent.getStringExtra("click_flag");
		if ("person".equals(click_flag)) { // 如果是点击 person按钮
			// 接收Intent传递的Person对象
			Person person =(Person) intent.getSerializableExtra("person");  
			textView.setText(person.toString());	
			
	//		textView.setText("test :"+intent.getStringExtra("test"));
			
		} else if ("persons".equals(click_flag)) {// 如果是点击 persons按钮
			
			// 接收Intent传递的List<Person>参数
			@SuppressWarnings("unchecked")
			List<Person> list = (List<Person>) intent
					.getSerializableExtra("persons");
			String persons = "";
			for (Person person : list) {
				persons += person.toString() + "\n";
			}
			textView.setText(persons);	
	
		}else if ("listString".equals(click_flag)) {
			List<String> list = (List<String>) intent
					.getStringArrayListExtra("listString");

			String listString = "";
			for (String s : list) {
				listString += s + "\n";
			}
			textView.setText(listString);
		} else if ("listMap".equals(click_flag)) {
			//接收Intent传递的List<Map<String,Object>>参数
			@SuppressWarnings("unchecked")
			List<Map<String, Object>> list = (List<Map<String, Object>>) intent
					.getSerializableExtra("listMap");

			String listMapString = "";
			for (Map<String, Object> map : list) {
				// 遍历一个Map
				for (Map.Entry<String, Object> entry : map.entrySet()) {
					String key = entry.getKey();
					Object value = entry.getValue();					
					listMapString += " " + key + " : " + value + " ";
				}
				listMapString += "\n";
			}

			textView.setText(listMapString+intent.getStringExtra("jsonString"));
		}
		
	}

}

3.FastJsonTools.java

package com.fastjson.tools;

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

import com.alibaba.fastjson.JSON;
import com.alibaba.fastjson.TypeReference;

public class FastJsonTools {

	/**
	 * 用fastjson 将json字符串解析为一个 JavaBean
	 * 
	 * @param jsonString
	 * @param cls
	 * @return
	 */
	public static <T> T getPerson(String jsonString, Class<T> cls) {
		T t = null;
		try {
			t = JSON.parseObject(jsonString, cls);
		} catch (Exception e) {
			// TODO: handle exception
			e.printStackTrace();
		}
		return t;
	}

	/**
	 * 用fastjson 将json字符串 解析成为一个 List<JavaBean> 及 List<String>
	 * 
	 * @param jsonString
	 * @param cls
	 * @return
	 */
	public static <T> List<T> getPersons(String jsonString, Class<T> cls) {
		List<T> list = new ArrayList<T>();
		try {
			list = JSON.parseArray(jsonString, cls);
		} catch (Exception e) {
			// TODO: handle exception
		}
		return list;
	}

	/**
	 * 用fastjson 将jsonString 解析成 List<Map<String,Object>>
	 * 
	 * @param jsonString
	 * @return
	 */
	public static List<Map<String, Object>> getListMap(String jsonString) {
		List<Map<String, Object>> list = new ArrayList<Map<String, Object>>();
		try {
			// 两种写法
			// list = JSON.parseObject(jsonString, new
			// TypeReference<List<Map<String, Object>>>(){}.getType());

			list = JSON.parseObject(jsonString,
					new TypeReference<List<Map<String, Object>>>() {
					});
		} catch (Exception e) {
			// TODO: handle exception
		}
		return list;

	}

}

4.Person.java

package com.gson.data;

import java.io.Serializable;



public class Person implements Serializable{
	
	
	private int id;
	private String name;
    private String address;
	
	public Person() {
		// TODO Auto-generated constructor stub
	}

	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 String getAddress() {
		return address;
	}

	public void setAddress(String address) {
		this.address = address;
	}

	public Person(int id, String name, String address) {
		super();
		this.id = id;
		this.name = name;
		this.address = address;
	}

	@Override
	public String toString() {
		return "Person [id=" + id + ", name=" + name + ", address=" + address
				+ "]";
	}
	

}

5.HttpUtils.java

package com.gson.http;

import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.net.HttpURLConnection;
import java.net.URL;

import android.annotation.SuppressLint;
import android.os.StrictMode;


/** 接收path服务器端返回的 InputStream, 转换为 json字符串
 * @author ben
 *
 */
public class HttpUtils {
	
	public static String getJsonContent(String url_path ,String encode){
		
		String jsonString = "";
		try {
			URL url = new URL(url_path);			
			HttpURLConnection connection = (HttpURLConnection)url.openConnection();
			
			connection.setConnectTimeout(3000);
			connection.setRequestMethod("GET");
			connection.setDoInput(true);  //从服务器获得数据
			
			int responseCode = connection.getResponseCode();			
			
			if (200 == responseCode) {
				jsonString = changeInputStream(connection.getInputStream(),encode);
				
			}
			
		
			
		} catch (Exception e) {
			// TODO: handle exception
		}
		
	//
		return jsonString;
	}

	private static String changeInputStream(InputStream inputStream , String encode) throws IOException {
		// TODO Auto-generated method stub
		String  jsonString = null;
		
		ByteArrayOutputStream outputStream = new ByteArrayOutputStream();
		byte[] data = new byte[1024];
		int len = 0;
		while((len=inputStream.read(data))!=-1){
			outputStream.write(data, 0, len);
		}
		
		jsonString = new String(outputStream.toByteArray(), encode);

		inputStream.close();
		
		
		return jsonString;
	}
	
}

6.activity_matin.xml

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
	xmlns:tools="http://schemas.android.com/tools"
	android:layout_width="match_parent"
	android:layout_height="match_parent"
	android:orientation="vertical">
	<Button
		android:id="@+id/person"
		android:layout_width="match_parent"
		android:layout_height="wrap_content"
		android:text="解析Person数据" />
	<Button
		android:id="@+id/persons"
		android:layout_width="match_parent"
		android:layout_height="wrap_content"
		android:text="解析Persons数据" />
	<Button
		android:id="@+id/listString"
		android:layout_width="match_parent"
		android:layout_height="wrap_content"
		android:text="解析listString数据" />
	<Button
		android:id="@+id/listMap"
		android:layout_width="match_parent"
		android:layout_height="wrap_content"
		android:text="解析listMap数据" />
</LinearLayout>

7.activity_other.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
	android:layout_width="match_parent"
	android:layout_height="match_parent"
	android:orientation="vertical" >
	
	<TextView 
		android:id="@+id/msg"
		android:layout_width="match_parent"
		android:layout_height="wrap_content"		
		
		/>
	
</LinearLayout>

8.AndroidManifest.xml

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
	package="com.android.mygson"
	android:versionCode="1"
	android:versionName="1.0" >
	<uses-sdk
		android:minSdkVersion="8"
		android:targetSdkVersion="19" />
	
	<!-- 添加访问网络的授权 -->
	<uses-permission android:name="android.permission.INTERNET" />
	
	<application
		android:allowBackup="true"
		android:icon="@drawable/ic_launcher"
		android:label="@string/app_name"
		android:theme="@style/AppTheme" >
		<activity
			android:name="com.android.mygson.MainActivity"
			android:label="@string/app_name" >
			<intent-filter>
				<action android:name="android.intent.action.MAIN" />
				<category android:name="android.intent.category.LAUNCHER" />
			</intent-filter>
		</activity>
		<activity android:name=".OtherActivity"></activity>
	</application>
</manifest>


-----------------------------------------------------------------------------------------------------------------

注意一点:

泛型方法

客户端:FastJsonToos.java 泛型方法的写法。












fastjson生成和解析json数据,古老的榕树,5-wow.com

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