json解析-Gson

 一、 谷歌GSON这个Java类库可以把Java对象转换成JSON，也可以把JSON字符串转换成一个相等的Java对象。Gson支持任意复杂Java对象包括没有源代码的对象。

 二、Gson解析Json步骤

 A、服务器端将数据转换成json字符串

   首先、服务器端项目要导入Gson的jar包到BuiltPath中。（

Gson的jar：http://code.google.com/p/google-gson/   我们还可以下载gson的帮助文档）





先写一个person对象

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

 }

 public class PersonService {
     //一个person对象
     public Person getPerson(){
         Person person=new Person(1001,"hang","suqian");
         return person;
     }
     //一组person对象
     public List<Person> getlistPerson(){
         List<Person> list=new ArrayList<Person>();
         Person person1=new Person(1001,"zhang","suqian");
         Person person2=new Person(2002,"hang","yangzhou");
         list.add(person1);
         list.add(person2);

         return list;

     }
     //字符串数组
     public List<String> getlistString(){
         List<String> list=new ArrayList<String>();
         list.add("beijing");
         list.add("suqian");
         return list;
     }
     //Map对象
     public List<Map<String,Object>> getlistMap(){
         List<Map<String,Object>> list=new ArrayList<Map<String,Object>>();
         Map<String,Object> map1=new HashMap<String, Object>();
         map1.put("id", 1001);
         map1.put("name","zhang");
         map1.put("address", "beijing");
         Map<String,Object> map2=new HashMap<String, Object>();
         map2.put("id", 1002);
         map2.put("name","hang");
         map2.put("address", "shanghai");
         list.add(map1);
         list.add(map2);
         return list;
     }

 }




android客户端解析

 package com.example.andorid_json;

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

 import com.google.gson.Gson;
 import com.google.gson.reflect.TypeToken;

 import android.widget.EditText;

 public class GsonTools {

     public static <T> T getPerson(String jsonString, Class<T> cls) {
         T t = null;
         try {
             Gson gson = new Gson();
             t = gson.fromJson(jsonString, cls);

         } catch (Exception e) {
             e.printStackTrace();
         }
         return t;
     }

     public static <T> List<T> getPersons(String jsonString, Class<T> cls) {
         List<T> list = new ArrayList<T>();
         try {
             Gson gson = new Gson();
             list = gson.fromJson(jsonString, new TypeToken<List<T>>() {
             }.getType());

         } catch (Exception e) {
             e.printStackTrace();
         }
         return list;
     }

     public static List<String> getList(String jsonString) {
         List<String> list = new ArrayList<String>();
         try {
             Gson gson = new Gson();
             list = gson.fromJson(jsonString, new TypeToken<List<String>>() {
             }.getType());
         } catch (Exception e) {
             // TODO: handle exception
         }
         return list;

     }
     public static List<Map<String,Object>> listKeyMap(String jsonString){
         List<Map<String,Object>> list=new ArrayList<Map<String,Object>>();
         try {
             Gson gson = new Gson();
             list = gson.fromJson(jsonString, new TypeToken<List<Map<String,Object>>>() {
             }.getType());
         } catch (Exception e) {
             // TODO: handle exception
         }
         return list;
     }


 }