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 -->
- <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。
http://blog.csdn.net/neu_yousei/article/details/23184727