Android学习——解析JSON数据（天气案例）
学习记录：
简单学习一下Android Studio课程中的解析JSON数据。
参考资料： Android JSON数据解析
案列中用到的API地址：
地址1：http://api.qingyunke.com/api.php?key=free&appid=0&msg=上海天气
地址2：http://t.weather.itboy.net/api/weather/city/101020100
案例效果：
初运行：
点击 “简单天气” 按钮：
点击 “复杂天气” 按钮
案列代码
布局文件：activity_main.xml
布局比较简单：2个button 和 1个textView
主活动类：MainActivity.java
import androidx.appcompat.app.AppCompatActivity;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;
import org.json.JSONArray;
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.URL;
public class MainActivity extends AppCompatActivity {
private Button btn1,btn2;
private TextView textView;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
textView=findViewById(R.id.textView);
btn1=findViewById(R.id.button);
btn2=findViewById(R.id.button2);
btn1.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
sendRequestWithHttpURLConnection();
}
});
btn2.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
sendRequestWithHttpURLConnection2();
}
});
}
private void sendRequestWithHttpURLConnection() {
new Thread(new Runnable() {
@Override
public void run() {
HttpURLConnection connection = null;
BufferedReader reader = null;
try {
URL url = new URL("http://api.qingyunke.com/api.php?key=free&appid=0&msg=上海天气");
connection = (HttpURLConnection) url.openConnection();
connection.setRequestMethod("GET");
connection.setConnectTimeout(8000);
connection.setReadTimeout(8000);
if(connection.getResponseCode()==200){
InputStream in = connection.getInputStream();
reader = new BufferedReader(new InputStreamReader(in));
StringBuilder response = new StringBuilder();
String line;
while ((line = reader.readLine()) != null) {
response.append(line);
}
pareJSON1(response.toString());
}
} catch (Exception e) {
e.printStackTrace();
} finally {
if (reader != null) {
try {
reader.close();
} catch (IOException e) {
e.printStackTrace();
}
}
if (connection != null) {
connection.disconnect();
}
}
}
}).start();
}
private void sendRequestWithHttpURLConnection2() {
new Thread(new Runnable() {
@Override
public void run() {
HttpURLConnection connection = null;
BufferedReader reader = null;
try {
URL url = new URL("http://t.weather.itboy.net/api/weather/city/101020100");
connection = (HttpURLConnection) url.openConnection();
connection.setRequestMethod("GET");
connection.setConnectTimeout(8000);
connection.setReadTimeout(8000);
if(connection.getResponseCode()==200) {
InputStream in = connection.getInputStream();
reader = new BufferedReader(new InputStreamReader(in));
StringBuilder response = new StringBuilder();
String line;
while ((line = reader.readLine()) != null) {
response.append(line);
}
pareJSON2(response.toString());
}
} catch (Exception e) {
e.printStackTrace();
} finally {
if (reader != null) {
try {
reader.close();
} catch (IOException e) {
e.printStackTrace();
}
}
if (connection != null) {
connection.disconnect();
}
}
}
}).start();
}
//解析 1
private void pareJSON1(String jsonData){
try {
JSONObject jsonObject=new JSONObject(jsonData);
String result=jsonObject.getString("result");
String content=jsonObject.getString("content");
Log.d("MainActivity","今天的天气是：\n"+content);
runOnUiThread(new Runnable() {
@Override
public void run() {
textView.setText("");
textView.append(content);
}
});
}catch (Exception e){
e.printStackTrace();
}
}
//解析 2
private void pareJSON2(String jsonData){
try {
JSONObject jsonObject=new JSONObject(jsonData);
String date=jsonObject.getString("date");
StringBuilder weather=new StringBuilder();
weather.append("日期: "+date+"\n");
String cityInfo=jsonObject.getString("cityInfo");
JSONObject cityinfoObject=new JSONObject(cityInfo);
String city=cityinfoObject.getString("city");
weather.append("城市: "+city+"\n");
String data=jsonObject.getString("data");
JSONObject dataObj=new JSONObject(data);
weather.append("温度: "+dataObj.getString("wendu")+"\n");
weather.append("湿度: "+dataObj.getString("shidu")+"\n");
String forecast=dataObj.getString("forecast");
JSONArray forecast_arr=new JSONArray(forecast);
for (int i = 0; i < forecast_arr.length(); i++) {
JSONObject jo=forecast_arr.getJSONObject(i);
String next_date=jo.getString("ymd");
String high=jo.getString("high");
String week=jo.getString("week");
Log.d("MainActivity", "预报日期: "+next_date);
Log.d("MainActivity", "高温: "+high);
Log.d("MainActivity", "星期: "+week);
weather.append(next_date+" | "+high+" | "+week+"\n");
}
runOnUiThread(new Runnable() {
@Override
public void run() {
textView.setText("");
textView.append(weather);
}
});
}catch (Exception e){
e.printStackTrace();
}
}
}
添加网络访问权限：AndroidManifest.xml
<uses-permission android:name="android.permission.INTERNET" />
这样就完成啦~
2022.5.31 更新了布局文件的代码给需要的小伙伴！
activity_main.xml:
<androidx.constraintlayout.widget.ConstraintLayout 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"
tools:context=".MainActivity"
android:layout_margin="30dp">
<TextView
android:id="@+id/textView"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:text=" "
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintHorizontal_bias="0.495"
app:layout_constraintLeft_toLeftOf="parent"
app:layout_constraintRight_toRightOf="parent"
app:layout_constraintTop_toBottomOf="@+id/button2"
app:layout_constraintVertical_bias="0.068" />
<Button
android:id="@+id/button"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:text="简单天气"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent" />
<Button
android:id="@+id/button2"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:text="复杂天气"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toBottomOf="@+id/button" />
androidx.constraintlayout.widget.ConstraintLayout>