Android学习之解析JSON

在Tomcat服务器上放一个json文件

文件内容

[{"id":"01","name":"tiger","age":"12"},{"id":"02","name":"cat","age":"1"},{"id":"03","name":"dog","age":"2"}]

Manifest中加入联网许可

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

在项目中添加OkHttp库的依赖

compile 'com.squareup.okhttp3:okhttp:3.2.0'compile 'com.squareup.okio:okio:1.6.0'

activity_main.xml

<LinearLayout    xmlns:android="http://schemas.android.com/apk/res/android"    xmlns:tools="http://schemas.android.com/tools"    xmlns:app="http://schemas.android.com/apk/res-auto"    android:layout_width="match_parent"    android:layout_height="match_parent"    tools:context="com.example.konghao.json.MainActivity">    <ListView        android:id="@+id/ListView"        android:layout_width="wrap_content"        android:layout_height="417dp"/></LinearLayout>

item.xml

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"    android:orientation="vertical" android:layout_width="match_parent"    android:layout_height="match_parent">    <TextView        android:id="@+id/name"        android:textSize="18dp"        android:layout_width="wrap_content"        android:layout_height="wrap_content" />    <TextView        android:id="@+id/age"        android:textSize="18dp"        android:layout_width="wrap_content"        android:layout_height="wrap_content" /></LinearLayout>

User类

public class User {    private String id;    private String name;    private String age;    public User (String id,String name,String age){        this.id = id;        this.name = name;        this.age = age;    }    public String getId(){        return id;    }    public String getName(){        return name;    }    public String getAge(){        return age;    }}

User的适配器，让他能够在ListView中显示

public class UserAdapter extends ArrayAdapter<User> {    private int resourceId;    public UserAdapter(Context context, int textViewResourceId, List<User> objects){        super(context,textViewResourceId,objects);        resourceId = textViewResourceId;    }    @Override    public View getView(int position, View converView, ViewGroup parent){        User user = getItem(position);//获取当前User实例        View view = LayoutInflater.from(getContext()).inflate(resourceId,parent,false);        TextView name = (TextView) view.findViewById(R.id.name);        TextView age = (TextView) view.findViewById(R.id.age);        name.setText(user.getName());        age.setText(user.getAge());        return view;    }}

MainActivity.java 解析JSON数据

import okhttp3.OkHttpClient;import okhttp3.Request;import okhttp3.Response;public class MainActivity extends AppCompatActivity {    private List<User> UserList = new ArrayList<>();    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_main);        UserAdapter adapter = new UserAdapter(MainActivity.this,                R.layout.item,UserList);        ListView listView = (ListView) findViewById(R.id.ListView);        listView.setAdapter(adapter);        initUser();    }    //在线程里解析JSON数据    private void initUser() {        new Thread(new Runnable() {            @Override            public void run() {                try{                    OkHttpClient client = new OkHttpClient();//创建OkHttpClient的实例                    Request request = new Request.Builder()  //创建一个Request对象，发起一条HTTP请求                            .url("http://www.khqust.top/json/user.json")//设置目标网络地址                            .build();                    Response response = client.newCall(request).execute();//创建一个Call对象发送请求并获取服务器返回的数据                    String responseData = response.body().string();//得到具体返回内容                    DealData(responseData);//处理返回内容                } catch (IOException e) {                    e.printStackTrace();                }            }        }).start();    }    private void DealData(String responseData) {        try{            JSONArray jsonArray = new JSONArray(responseData);            for(int i = 0;i<jsonArray.length();i++){                JSONObject jsonObject = jsonArray.getJSONObject(i);                String id = jsonObject.getString("id");                String name = jsonObject.getString("name");                String age = jsonObject.getString("age");                User user = new User(id,name,age);                UserList.add(user);            }        } catch (JSONException e) {            e.printStackTrace();        }    }}

效果：