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

[java] view
plaincopy

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

[java] view
plaincopy

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

[java] view
plaincopy

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

[java] view
plaincopy

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

[java] view
plaincopy

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

[java] view
plaincopy

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

[java] view
plaincopy

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

[java] view
plaincopy

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

[java] view
plaincopy

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

[java] view
plaincopy

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

[html] view
plaincopy

<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

[html] view
plaincopy

<?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

[html] view
plaincopy

<?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 -->

<span style="color:#ff0000;"><uses-permission android:name="android.permission.INTERNET" />

</span>

<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>

<span style="color:#ff0000;"><activity android:name=".OtherActivity"></activity></span>

</application>

</manifest>

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注意一点：

泛型方法

客户端：FastJsonToos.java 泛型方法的写法。