android的从服务器取得json对象进行解析

先写服务器端的代码，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;   }    }

初始化一下person对象

public class JsonService {   //一个person对象   public Person getPerson(){    Person person=new Person(1001,"hang","suqian");    return person;   }    }

服务器端json的工具类

public class JsonToos {   public static String CreateJsonString(String key,Object value){    //生成json的string    JSONObject jsonObject=new JSONObject();        jsonObject.put(key,value);      return jsonObject.toString();       }    }

服务端的servlet

public class JsonAction extends HttpServlet {   /**    *     */   private static final long serialVersionUID = 1L;   private JsonService service;      /**       * @see HttpServlet#HttpServlet()       */      public JsonAction() {          super();          // TODO Auto-generated constructor stub      }        protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {       doPost(request, response);   }        protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {    response.setContentType("text/html;charset=utf-8");    request.setCharacterEncoding("utf-8");    response.setCharacterEncoding("utf-8");    PrintWriter out=response.getWriter();        String jsonString=JsonToos.CreateJsonString("person",service.getPerson());       out.println(jsonString);       out.flush();       out.close();      }   @Override   public void init() throws ServletException {    service=new JsonService();   }    }

 

下面为android端的代码

注意

<uses-permission android:name="android.permission.INTERNET"/>

这个一定要加的，网络访问权限

定义person的对象同上

下面是http的工具类，主要是http访问，获取json的字符串

public class HttpUtils {   public static String getJsonContent(String path){    try {     URL url=new URL(path);     HttpURLConnection connection=(HttpURLConnection) url.openConnection();     connection.setConnectTimeout(3000);     connection.setRequestMethod("GET");     connection.setDoInput(true);     int code=connection.getResponseCode();     if(code==200){      return changeInputString(connection.getInputStream());     }    } catch (Exception e) {     // TODO: handle exception    }    return "";   }     private static String changeInputString(InputStream inputStream) {        String jsonString="";    ByteArrayOutputStream outPutStream=new ByteArrayOutputStream();    byte[] data=new byte[1024];    int len=0;    try {     while((len=inputStream.read(data))!=-1){      outPutStream.write(data, 0, len);     }     jsonString=new String(outPutStream.toByteArray());        } catch (Exception e) {     // TODO Auto-generated catch block     e.printStackTrace();    }    return jsonString;   }    }

下面为解析json字符串，把值赋给person对象

public class JsonTools {     public static Person getPerson(String key, String jsonString) {    Person person = new Person();        try {     JSONObject jsonObject = new JSONObject(jsonString);     JSONObject personObject = jsonObject.getJSONObject(key);       person.setId(personObject.getInt("id"));     person.setName(personObject.getString("name"));     person.setAddress(personObject.getString("address"));    } catch (Exception e) {     // TODO: handle exception    }    return person;   }     public static List<Person> getPersons(String key, String jsonString) {    List<Person> list = new ArrayList<Person>();    try {     JSONObject jsonObject = new JSONObject(jsonString);     JSONArray jsonArray = jsonObject.getJSONArray(key);     for (int i = 0; i < jsonArray.length(); i++) {      JSONObject jsonObject2 = jsonArray.getJSONObject(i);      Person person = new Person();      person.setId(jsonObject2.getInt("id"));      person.setName(jsonObject2.getString("name"));      person.setAddress(jsonObject2.getString("address"));      list.add(person);     }    } catch (Exception e) {     // TODO: handle exception    }    return list;   }     public static List<String> getlistString(String key, String jsonString) {    List<String> list = new ArrayList<String>();    try {     JSONObject jsonObject = new JSONObject(jsonString);     JSONArray jsonArray = jsonObject.getJSONArray(key);     for (int i = 0; i < jsonArray.length(); i++) {        String msg = jsonArray.getString(i);      list.add(msg);     }      } catch (Exception e) {     // TODO: handle exception    }      return list;   }     public static List<Map<String,Object>> getlistMap(String key, String jsonString){    List<Map<String,Object>> list=new ArrayList<Map<String,Object>>();    try {     JSONObject jsonObject = new JSONObject(jsonString);     JSONArray jsonArray = jsonObject.getJSONArray(key);     for (int i = 0; i < jsonArray.length(); i++) {      JSONObject jsonObject2 = jsonArray.getJSONObject(i);              Map<String,Object> map=new HashMap<String, Object>();              Iterator<String> iterator=jsonObject2.keys();                         while(iterator.hasNext()){               String json_key=iterator.next();               Object json_value=jsonObject2.get(json_key);               if(json_value==null){                json_value="";               }               map.put(json_key, json_value);              }        list.add(map);     }     }catch(Exception e){      e.printStackTrace();     }    return list;   }  }

android点击button触发的事件

@Override   public void onClick(View v) {        switch (v.getId()) {    case  R.id.person:     path="http://192.168.123.1/http/JsonAction";    String jsonstring=HttpUtils.getJsonContent(path);    Log.i(TAG,"1212"+jsonstring);        Person person=JsonTools.getPerson("person", jsonstring);    Log.i(TAG,person.toString());    break;      default:     break;    }   }    }

完成了json的解析！！！