解析json如同解析xml一样，步骤差不多，详情可以看我上一篇解析xml的步骤，这里是在生成json中有不同，这里列举了原生态，gson,FastJson三种方式： 
依旧首先是在eclipse中生成json 首先getData.jsp
<%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%><!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"><html><head><meta http-equiv="Content-Type" content="text/html; charset=UTF-8"><title>Insert title here</title></head><body><a href="studentActiongetJson.action">获取json数据</a></body></html>接下来是有个student的实体类
PRivate String name; private String sex;然后在StudentAction中写一个方法
public String getJson() throws Exception { //查询数据库，得到数据 List<Student> students=new ArrayList<>(); for (int i = 0; i <=20; i++) { Student student=new Student("娜娜", "女"+i); students.add(student); } JSONObject jsonObject=new JSONObject(); jsonObject.put("clazz", "150825"); jsonObject.put("num", students.size()); JSONArray jsonArray=new JSONArray(); for (Student s : students) { JSONObject jsonObject2=new JSONObject(); jsonObject2.put("name", s.getName()); jsonObject2.put("sex", s.getSex()); jsonArray.add(jsonObject2); } jsonObject.put("students", jsonArray); //将对象集合保存到请求域中 ServletActionContext.getRequest().setAttribute("students", jsonObject.toString()); return "dataResultjson"; }在Struts.xml中
<action name="studentAction*" class="com.zking.action.StudentAction" method="{1}"> <result name="dataResultjson">dataResultjson.jsp</result> </action>最后生成jsondata Resultjson.jsp
<%@ page language="java" contentType="text/plain; charset=UTF-8" pageEncoding="UTF-8"%>${students}接下来是在Androidstudio中进行解析，和解析xml步骤相似 activity_main.xml
<Button android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="获取Json" android:onClick="getJson" /> <ListView android:layout_width="match_parent" android:layout_height="wrap_content" android:id="@+id/lv_main_list" ></ListView>这里为了获取IP地址方便，可以在 strings.xml中
<resources> <string name="app_name">parse_json</string> <string name="server_name">http://192.168.43.109:8080/testssh/</string></resources>这里需要两个实体类 BigStudent.java
package com.example.parse_json;import java.util.List;public class BigStudent { private String clazz; private int num; private List<Student> students; public BigStudent() { } public BigStudent(String clazz, int num, List<Student> students) { this.clazz = clazz; this.num = num; this.students = students; } public String getClazz() { return clazz; } public void setClazz(String clazz) { this.clazz = clazz; } public int getNum() { return num; } public void setNum(int num) { this.num = num; } public List<Student> getStudents() { return students; } public void setStudents(List<Student> students) { this.students = students; }}student.java
package com.example.parse_json;public class Student { private String name; private String sex; public Student() { super(); } public Student(String name, String sex) { super(); this.name = name; this.sex = sex; } public String getName() { return name; } public void setName(String name) { this.name = name; } public String getSex() { return sex; } public void setSex(String sex) { this.sex = sex; }}接下来是关键代码 ActivityMain.java 这里面有三种解析方式，原生态，gson，这一种方式在studio在加入gson的library便可，右击项目Open Moudle Setting 以及FastJson这是由阿里巴巴公司提供的，可以将这一jar放入项目的libs中
package com.example.parse_json;import android.app.ProgressDialog;import android.os.AsyncTask;import android.support.v7.app.AppCompatActivity;import android.os.Bundle;import android.util.Log;import android.view.View;import android.view.ViewGroup;import android.widget.BaseAdapter;import android.widget.LinearLayout;import android.widget.ListView;import android.widget.TextView;import com.alibaba.fastjson.JSON;import com.google.gson.Gson;import org.json.JSONArray;import org.json.JSONException;import org.json.JSONObject;import java.io.BufferedReader;import java.io.IOException;import java.io.InputStream;import java.io.InputStreamReader;import java.net.HttpURLConnection;import java.net.MalformedURLException;import java.net.URL;import java.util.ArrayList;import java.util.List;public class MainActivity extends AppCompatActivity { List<Student> studentList=new ArrayList<>(); private ListView lv_main_list; private MyAdater myAdater; private ProgressDialog progressDialog; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); //添加listview lv_main_list = (ListView) findViewById(R.id.lv_main_list); //实例化适配器 myAdater = new MyAdater(); //设置适配器 lv_main_list.setAdapter(myAdater); //实例化进度条对话框 progressDialog = new ProgressDialog(this); progressDialog.setMessage("json正在加载中....."); } class MyAdater extends BaseAdapter { @Override public int getCount() { return studentList.size(); } @Override public Object getItem(int i) { return studentList.get(i); } @Override public long getItemId(int i) { return i; } @Override public View getView(int i, View view, ViewGroup viewGroup) { LinearLayout layout=new LinearLayout(MainActivity.this); layout.setOrientation(LinearLayout.HORIZONTAL); TextView textViewName=new TextView(MainActivity.this); textViewName.setText(studentList.get(i).getName()); TextView textViewsex=new TextView(MainActivity.this); textViewsex.setText(studentList.get(i).getSex()); layout.addView(textViewName); layout.addView(textViewsex); return layout; } } public void getJson(View view){ new MyTask().execute(); } class MyTask extends AsyncTask{ @Override protected void onPreExecute() { super.onPreExecute(); progressDialog.show(); } @Override protected Object doInBackground(Object[] objects) { String path=getString(R.string.server_name)+"studentActiongetJson.action"; try { URL url=new URL(path); HttpURLConnection connection= (HttpURLConnection) url.openConnection(); connection.setRequestMethod("GET"); connection.setConnectTimeout(5000); if (connection.getResponseCode()==200){ InputStream is=connection.getInputStream(); StringBuffer sb=new StringBuffer(); String str=null; BufferedReader br=new BufferedReader(new InputStreamReader(is)); while ((str=br.readLine())!=null){ sb.append(str); }// Log.i("test",sb.toString());// Log.i("test","ff"); //原生态// try {// JSONObject jsonObject=new JSONObject(sb.toString());// String clazz=jsonObject.getString("clazz");// Log.i("test","clazz"+clazz);// int num=jsonObject.getInt("num");// Log.i("test","1111num"+num);// JSONArray jsonArray= jsonObject.getJSONArray("students");//// for(int i=0;i<jsonArray.length();i++){// JSONObject o= (JSONObject) jsonArray.getJSONObject(i);// String name= o.getString("name");// String sex= o.getString("sex");// Log.i("test",name+""+sex);//// }//// } catch (JSONException e) {// e.printStackTrace();// } //0.2使用Gson解析json// Gson gson=new Gson();// BigStudent b= gson.fromJson(sb.toString(),BigStudent.class);// String clazz= b.getClazz();// int num=b.getNum();// Log.i("test","1111num"+num+"clazz:"+clazz);// List<Student> students= b.getStudents();// for (Student student : students) {// Log.i("test",student.getName()+" "+student.getSex());// } //03.FastJson BigStudent bigStudent=JSON.parSEObject(sb.toString(),BigStudent.class); String clazz=bigStudent.getClazz(); int num=bigStudent.getNum(); Log.i("test","aaaaaanum:"+num+" clazz:"+clazz); List<Student> students=bigStudent.getStudents(); for (Student student : students) { Log.i("test",student.getName()+" "+student.getSex()); studentList.add(student); } br.close(); } } catch (MalformedURLException e) { e.printStackTrace(); } catch (IOException e) { e.printStackTrace(); } return null; } @Override protected void onPostExecute(Object o) { super.onPostExecute(o); //通知适配器发生改变 myAdater.notifyDataSetChanged(); progressDialog.cancel(); } }}最后依然是加入清单权限
<uses-permission android:name="android.permission.INTERNET"></uses-permission>在我上一篇中有解析xml的步骤，可以去看看
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