Android ：安卓第一行代码学习笔记之 解析JSON格式数据

Posted 2021-12-18 JMW1407

解析JSON格式数据

• 解析JSON格式数据
• • 1、使用JSONObject
  • 2、使用GSON解析
  • 3、使用实例
• 参考

解析JSON格式数据

1、使用JSONObject

1、首先接收服务器返回的数据

private void okHttpRequest() 
        new Thread(new Runnable() 
            @Override
            public void run() 
                try 
                    OkHttpClient client = new OkHttpClient();
                    Request request = new Request.Builder()
                            //指定访问的服务器地址是电脑本机
                            .url("http://10.0.2.2/get_data.json")
                            .build();
                    Response response = client.newCall(request).execute();
                    String responseData = response.body().string();
                    parseJSONWITHJSONObject(responseData);//解析数据
                 catch (IOException e) 
                    e.printStackTrace();
                
            
        ).start();
    

2、解析JSON格式数据

private void parseJSONWITHJSONObject(String jsonData) 
        try 
            JSONArray jsonArray = new JSONArray(jsonData);
            for (int i = 0; i < jsonArray.length(); i++) 
                JSONObject jsonobject = jsonArray.getJSONObject(i);
                String id = jsonobject.getString("id");
                String name = jsonobject.getString("name");
                String version = jsonobject.getString("version");
            
         catch (JSONException e) 
            e.printStackTrace();
        
    

2、使用GSON解析

1.首先添加依赖

implementation 'com.google.code.gson:gson:2.7'

GSON库主要就是可以将一段JSON格式的字符串自动映射成一个对象，从而不需要我们在手动去编写代码进行解析。

比如说一段JSON格式数据如下：

String jsonData = "name":"Tom","age":20;

那我们就可以定义一个Person类，并加入name和age字段，然后只需要调用如下代码就可以JSON数据自动解析成Person对象：

Gson gson = new Gson();
Person person = gson.fromJson(jsonData, Person.class);

如果需要解析的是一段JSON数组会稍微麻烦一点，我们需要借助TypeToken将期望解析的数据类型传入到fromJson()方法中：

Gson gson = new Gson();
List<Person> people = gson.fromJson(jsonData, new TypeToken<List<Person>>().getType());

2、定义Person类

public class Person 
    private String id;
    private String name;
    private int age;
	
	/*
	getter and setter
	*/

3.接收服务器返回的数据

private void okHttpRequest() 
        new Thread(new Runnable() 
            @Override
            public void run() 
                try 
                    OkHttpClient client = new OkHttpClient();
                    Request request = new Request.Builder()
                            //指定访问的服务器地址是电脑本机
                            .url("http://10.0.2.2/get_data.json")
                            .build();
                    Response response = client.newCall(request).execute();
                    String responseData = response.body().string();
                    parseJSONWithGSON(responseData);//解析数据
                 catch (IOException e) 
                    e.printStackTrace();
                
            
        ).start();
    

4.解析JSON数据

private void parseJSONWithGSON(String jsonData) 
        Gson gson = new Gson();
        List<Person> people = gson.fromJson(jsonData, new TypeToken<List<Person>>().getType());
        for (Person person : people) 
            String id = person.getId();
            String name = person.getName();
            int age = person.getAge();
        
    

3、使用实例

1、定义原始的JSON数据如下（test.json）

[
	
		"name":"why",
		"age":"26",
		"sex":"male"
	,
	
		"name":"jr",
		"age":"24",
		"sex":"female"
	
]

2、MainActivity.java

package com.hfut.operationjson;
 
import android.os.Handler;
import android.os.Message;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.widget.EditText;
import android.widget.TextView;
 
import com.google.gson.Gson;
import com.google.gson.reflect.TypeToken;
 
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;
 
import java.io.IOException;
import java.util.List;
 
import okhttp3.OkHttpClient;
import okhttp3.Request;
import okhttp3.Response;
 
public class MainActivity extends AppCompatActivity 
 
    EditText jsonName;
    TextView jsonContent;
    Handler handler = new Handler() 
        @Override
        public void handleMessage(Message msg) 
            switch (msg.what) 
                case 1:
                    jsonContent.setText((String) msg.obj);
                    break;
 
            
        
    ;
 
    public final String localURL = "http://192.168.31.2:8088/";
    private static final String TAG = "MainActivity";
 
    @Override
    protected void onCreate(Bundle savedInstanceState) 
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        jsonName = findViewById(R.id.json_name);
        jsonContent = findViewById(R.id.json_content);
    
 
    public void jSONObjectParse(View view) 
        getData(view.getId());
    
 
    public void gSONParse(View view) 
        getData(view.getId());
    
 
    //JSONObject对象解析
    private String parseJSONwithJSONObject(String jsonData) 
        StringBuilder stringBuilder = new StringBuilder();
        try 
            JSONArray array = new JSONArray(jsonData);
            Log.i(TAG, "parseJSONwithJSONObject: "+array.length());
            //遍历json串，获取每一个json对象，在取键值对数据
            for (int i = 0; i < array.length(); i++) 
                JSONObject jsonObject = array.getJSONObject(i);
                String name = jsonObject.getString("name");
                String age = jsonObject.getString("age");
                String sex = jsonObject.getString("sex");
                stringBuilder.append("  name:"+name+";  age:"+age+";  sex:"+sex+"\\n");
            
         catch (JSONException e) 
            e.printStackTrace();
        
        return stringBuilder.toString();
    
 
    //GSON解析
    private String parseJSONwithGSON(String jsonData) 
        Gson gson=new Gson();
        StringBuilder stringBuilder = new StringBuilder();
        //通过json字符串获取对象数组
        List<Student> list=gson.fromJson(jsonData,new TypeToken<List<Student>>().getType());
            for (int i = 0; i < list.size(); i++) 
               Student student=list.get(i);
                String name = student.getName();
                String age =student.getAge();
                String sex = student.getSex();
                stringBuilder.append("  name:"+name+";  age:"+age+";  sex:"+sex+"\\n");
            
        return stringBuilder.toString();
    
 
 
    private void getData(final int methodID)
        final StringBuilder stringBuilder = new StringBuilder();
        new Thread(new Runnable() 
            @Override
            public void run() 
                String tempUrl = localURL + jsonName.getText().toString();
                OkHttpClient okHttpClient = new OkHttpClient();
                Request request = new Request.Builder()
                        .url(tempUrl)
                        .build();
                try 
                    Response response = okHttpClient.newCall(request).execute();
                    String result = response.body().string();
                    Message message = new Message();
                    String parsedData="";
                    //点击不同按钮，执行不同的解析方法
                    switch (methodID)
                        case R.id.JSONObjectWay:
                            parsedData=parseJSONwithJSONObject(result);
                            stringBuilder.append("解析方式为：JSONObjectWay\\n");
                            break;
                        case R.id.GSONWay:
                            parsedData=parseJSONwithGSON(result);
                            stringBuilder.append("解析方式为：GSONWay\\n");
                            break;
                    
                    stringBuilder.append("源数据为：\\n");
                    stringBuilder.append(result+"\\n");
                    stringBuilder.append("解析数据结果：\\n");
                    stringBuilder.append(parsedData);
                    message.what = 1;
                    message.obj = stringBuilder.toString();
                    handler.sendMessage(message);
                    Log.i(TAG, "run: " + result);
                 catch (IOException e) 
                    e.printStackTrace();
                
            
        ).start();
    

3、Student.java

package com.hfut.operationjson;
 
public class Student 
    private String name;
    private String age;
    private String sex;
 
    public String getName() 
        return name;
    
 
    public void setName(String name) 
        this.name = name;
    
 
    public String getAge() 
        return age;
    
 
    public void setAge(String age) 
        this.age = age;
    
 
    public String getSex() 
        return sex;
    
 
    public void setSex(String sex) 
        this.sex = sex;
    

4、activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    tools:context="com.hfut.operationjson.MainActivity">
 
    <EditText
        android:layout_marginTop="20dp"
        android:id="@+id/json_name"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:hint="请输入JSON文件名称"
        android:textSize="20dp" />
 
    <Button
        android:id="@+id/JSONObjectWay"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_marginTop="10dp"
        android:textAllCaps="false"
        android:onClick="jSONObjectParse"
        android:text="JSONObject解析JSON"
        android:textSize="20dp" />
 
    <Button
        android:id="@+id/GSONWay"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_marginTop="10dp"
        android:onClick="gSONParse"
        android:text="GSON解析JSON"
        android:textSize="20dp" />
 
    <ScrollView
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:layout_marginTop="10dp">
 
        <TextView
            android:textSize="20dp"
            android:textColor="@color/colorPrimary"
            android:id="@+id/json_content"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:hint="显示服务器JSON文件数据" />
    </ScrollView>
 
</LinearLayout>

实验结果

1、第一步：运行程序

第二步：点击“JSONObject解析JSON”

第三步：点击“GSON解析JSON”

参考

1、Android-解析JSON格式数据
2、https://blog.csdn.net/hfut_why/article/details/79919015