java - 在物理设备上成功启动 Activity 后，应用程序会立即停止。网络主线程异常

Question

这是我来自一个 android 项目的全部代码
翻译器.java:

import androidx.appcompat.app.AppCompatActivity;

import android.os.Bundle;
import android.view.View;
import android.widget.EditText;
import android.widget.TextView;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.net.HttpURLConnection;
import java.net.URL;
import java.net.URLEncoder;

public class Translator extends AppCompatActivity {

    EditText input;
    TextView translated;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
    }

        public void translate (View view) throws IOException {
            input = (EditText) findViewById(R.id.input);
            String text = input.getText().toString();
            translated = (TextView) findViewById(R.id.translatedText);

            String langFrom = "en";
            String langTo = "hi";

            // INSERT YOU URL HERE
            String urlStr = "https://script.google.com/macros/s/AKfycbxt1kjnGx5twzn8lGZopvHkivUCL-B8su8PLXsSRlByiAdRKgA/exec" +
                    "?q=" + URLEncoder.encode(text, "UTF-8") +
                    "&target=" + langTo +
                    "&source=" + langFrom;
            URL url = new URL(urlStr);
            StringBuilder response = new StringBuilder();
            HttpURLConnection con = (HttpURLConnection) url.openConnection();
            con.setRequestProperty("User-Agent", "Mozilla/5.0");
            BufferedReader in = new BufferedReader(new InputStreamReader(con.getInputStream()));
            String inputLine;
            while ((inputLine = in.readLine()) != null) {
                response.append(inputLine);
            }
            in.close();

            String output =  response.toString();
            translated.setText(output);
        }

}

Activity _main.xml:

<?xml version="1.0" encoding="utf-8"?>
<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"
    android:background="#FAF3BD"
    tools:context=".Translator">

    <TextView
        android:id="@+id/textView"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="@string/tagLine"
        android:textSize="36sp"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintLeft_toLeftOf="parent"
        app:layout_constraintRight_toRightOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent"
        app:layout_constraintVertical_bias="0.023" />

    <com.google.android.material.textfield.TextInputLayout
        android:id="@+id/textInputLayout"
        android:layout_width="300dp"
        android:layout_height="wrap_content"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintHorizontal_bias="0.144"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toBottomOf="@+id/textView"
        app:layout_constraintVertical_bias="0.069">

        <com.google.android.material.textfield.TextInputEditText
            android:id="@+id/input"
            android:layout_width="match_parent"
            android:layout_height="100dp"
            android:hint="@string/input"
            android:textSize="24sp" />
    </com.google.android.material.textfield.TextInputLayout>

    <Button
        android:id="@+id/translateButton"
        android:layout_width="175dp"
        android:layout_height="67dp"
        android:background="#FF9800"
        android:onClick="translate"
        android:text="@string/translateButton"
        android:textSize="30sp"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toBottomOf="@+id/textView"
        app:layout_constraintVertical_bias="0.46" />
    enter code here
    <com.google.android.material.textfield.TextInputLayout
        android:layout_width="300dp"
        android:layout_height="wrap_content"
        app:layout_constraintBottom_toTopOf="@+id/translateButton"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintHorizontal_bias="0.144"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toBottomOf="@+id/textInputLayout"
        app:layout_constraintVertical_bias="0.558">

        <com.google.android.material.textfield.TextInputEditText
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:hint="@string/target_language"
            android:textSize="24sp" />
    </com.google.android.material.textfield.TextInputLayout>

    <TextView
        android:id="@+id/translatedText"
        android:layout_width="305dp"
        android:layout_height="215dp"
        android:background="#FDDB73"
        android:scrollY="500dp"
        android:scrollbarAlwaysDrawVerticalTrack="true"
        android:scrollbarStyle="outsideOverlay"
        android:scrollHorizontally="false"
        android:shadowColor="#FFFFFF"
        android:text="@string/translated"
        android:textSize="24sp"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintHorizontal_bias="0.494"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toBottomOf="@+id/translateButton"
        app:layout_constraintVertical_bias="0.751" />



    <TextView
        android:id="@+id/textView3"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="@string/translated_text"
        android:textSize="30sp"
        app:layout_constraintBottom_toTopOf="@+id/translatedText"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintHorizontal_bias="0.497"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toBottomOf="@+id/translateButton"
        app:layout_constraintVertical_bias="0.731" />

    <View
        android:id="@+id/divider2"
        android:layout_width="350dp"
        android:layout_height="2dp"
        android:layout_marginTop="83dp"
        android:layout_marginBottom="12dp"
        android:background="?android:attr/listDivider"
        app:layout_constraintBottom_toTopOf="@+id/textView3"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="@+id/translateButton" />

</androidx.constraintlayout.widget.ConstraintLayout>

AndroidManifest.xml:

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.dhimanujjwal.anuvaad">

    <uses-permission android:name="android.permission.INTERNET"/>
    <application
        android:allowBackup="true"
        android:icon="@mipmap/ic_launcher"
        android:label="@string/app_name"
        android:roundIcon="@mipmap/ic_launcher_round"
        android:supportsRtl="true"
        android:theme="@style/AppTheme">
        <activity android:name=".Translator">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
    </application>

</manifest>

日志猫:

Process: com.dhimanujjwal.anuvaad, PID: 14480
    java.lang.IllegalStateException: Could not execute method for android:onClick
        at androidx.appcompat.app.AppCompatViewInflater$DeclaredOnClickListener.onClick(AppCompatViewInflater.java:414)
        at android.view.View.performClick(View.java:6412)
        at android.view.View$PerformClick.run(View.java:25341)
        at android.os.Handler.handleCallback(Handler.java:790)
        at android.os.Handler.dispatchMessage(Handler.java:99)
        at android.os.Looper.loop(Looper.java:214)
        at android.app.ActivityThread.main(ActivityThread.java:6977)
        at java.lang.reflect.Method.invoke(Native Method)
        at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:528)
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:910)
     Caused by: java.lang.reflect.InvocationTargetException
        at java.lang.reflect.Method.invoke(Native Method)
        at androidx.appcompat.app.AppCompatViewInflater$DeclaredOnClickListener.onClick(AppCompatViewInflater.java:409)
        at android.view.View.performClick(View.java:6412) 
        at android.view.View$PerformClick.run(View.java:25341) 
        at android.os.Handler.handleCallback(Handler.java:790) 
        at android.os.Handler.dispatchMessage(Handler.java:99) 
        at android.os.Looper.loop(Looper.java:214) 
        at android.app.ActivityThread.main(ActivityThread.java:6977) 
        at java.lang.reflect.Method.invoke(Native Method) 
        at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:528) 
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:910) 
     Caused by: android.os.NetworkOnMainThreadException
        at android.os.StrictMode$AndroidBlockGuardPolicy.onNetwork(StrictMode.java:1450)
        at java.net.Inet6AddressImpl.lookupHostByName(Inet6AddressImpl.java:102)
        at java.net.Inet6AddressImpl.lookupAllHostAddr(Inet6AddressImpl.java:90)
        at java.net.InetAddress.getAllByName(InetAddress.java:787)
        at com.android.okhttp.Dns$1.lookup(Dns.java:39)
        at com.android.okhttp.internal.http.RouteSelector.resetNextInetSocketAddress(RouteSelector.java:175)
        at com.android.okhttp.internal.http.RouteSelector.nextProxy(RouteSelector.java:141)
        at com.android.okhttp.internal.http.RouteSelector.next(RouteSelector.java:83)
        at com.android.okhttp.internal.http.StreamAllocation.findConnection(StreamAllocation.java:174)
        at com.android.okhttp.internal.http.StreamAllocation.findHealthyConnection(StreamAllocation.java:126)
        at com.android.okhttp.internal.http.StreamAllocation.newStream(StreamAllocation.java:95)
        at com.android.okhttp.internal.http.HttpEngine.connect(HttpEngine.java:299)
        at com.android.okhttp.internal.http.HttpEngine.sendRequest(HttpEngine.java:237)
        at com.android.okhttp.internal.huc.HttpURLConnectionImpl.execute(HttpURLConnectionImpl.java:461)
        at com.android.okhttp.internal.huc.HttpURLConnectionImpl.getResponse(HttpURLConnectionImpl.java:407)
        at com.android.okhttp.internal.huc.HttpURLConnectionImpl.getInputStream(HttpURLConnectionImpl.java:244)
        at com.android.okhttp.internal.huc.DelegatingHttpsURLConnection.getInputStream(DelegatingHttpsURLConnection.java:210)
        at com.android.okhttp.internal.huc.HttpsURLConnectionImpl.getInputStream(Unknown Source:0)
        at com.dhimanujjwal.anuvaad.Translator.translate(Translator.java:45)
        at java.lang.reflect.Method.invoke(Native Method) 
        at androidx.appcompat.app.AppCompatViewInflater$DeclaredOnClickListener.onClick(AppCompatViewInflater.java:409) 
        at android.view.View.performClick(View.java:6412) 
        at android.view.View$PerformClick.run(View.java:25341) 
        at android.os.Handler.handleCallback(Handler.java:790) 
        at android.os.Handler.dispatchMessage(Handler.java:99) 
        at android.os.Looper.loop(Looper.java:214) 
        at android.app.ActivityThread.main(ActivityThread.java:6977) 
        at java.lang.reflect.Method.invoke(Native Method) 
        at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:528) 
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:910) 

Answer 1

您收到 Caused by: android.os.NetworkOnMainThreadException .我认为它说明了一切。要执行这样的操作，您必须在另一个线程上执行此操作。您可以使用 JobIntentService .
在您的 list 文件中:

<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.example.teststackjava">

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

    <application
        android:allowBackup="true"
        android:icon="@mipmap/ic_launcher"
        android:label="@string/app_name"
        android:roundIcon="@mipmap/ic_launcher_round"
        android:supportsRtl="true"
        android:theme="@style/AppTheme">
        <activity android:name=".MainActivity">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
        <service
            android:name=".ExampleJobIntentService"
            android:permission="android.permission.BIND_JOB_SERVICE" />
    </application>

</manifest>

主要 Activity :

import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.widget.EditText;
import android.widget.TextView;

import androidx.appcompat.app.AppCompatActivity;
import androidx.lifecycle.Observer;

public class MainActivity extends AppCompatActivity
{
    EditText input;
    TextView translated;

    @Override
    protected void onCreate(Bundle savedInstanceState)
    {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
    }

    public void translate(View view)
    {
        input = (EditText) findViewById(R.id.input);
        String text = input.getText().toString();
        translated = (TextView) findViewById(R.id.translatedText);

        // setting observer to translated text
        ExampleJobIntentService.translatedText.observe(this,
                                                       new Observer<String>()
                                                       {
                                                           @Override
                                                           public void onChanged(String s)
                                                           {
                                                               translated.setText(s); // change text
                                                           }
                                                       }
        );

        Intent serviceIntent = new Intent(this,
                                          ExampleJobIntentService.class
        );
        serviceIntent.putExtra("inputExtra", text);
        ExampleJobIntentService.enqueueWork(this, serviceIntent);
    }
}

然后创建扩展 JobIntentService 的类:

import android.content.Context;
import android.content.Intent;
import android.util.Log;

import androidx.annotation.NonNull;
import androidx.core.app.JobIntentService;
import androidx.lifecycle.MutableLiveData;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.net.HttpURLConnection;
import java.net.URL;
import java.net.URLEncoder;

public class ExampleJobIntentService extends JobIntentService
{
    private static final String TAG = "ExampleJobIntentService";

    // This is data type which can be observed by another class
    public static MutableLiveData<String> translatedText = new MutableLiveData<>(); // I made it public, better to use private and getter

    static void enqueueWork(Context context, Intent work)
    {
        enqueueWork(context, ExampleJobIntentService.class, 123, work);
    }

    @Override
    public void onCreate()
    {
        super.onCreate();
        Log.d(TAG, "onCreate");
    }

    @Override
    protected void onHandleWork(@NonNull Intent intent)
    {
        Log.d(TAG, "onHandleWork");

        String input = intent.getStringExtra("inputExtra");

        String langFrom = "en";
        String langTo = "hi";

        // INSERT YOU URL HERE
        try
        {
            String urlStr = "https://script.google.com/macros/s/AKfycbxt1kjnGx5twzn8lGZopvHkivUCL-B8su8PLXsSRlByiAdRKgA/exec" +
                    "?q=" + URLEncoder.encode(input, "UTF-8") +
                    "&target=" + langTo +
                    "&source=" + langFrom;
            URL url = new URL(urlStr);
            StringBuilder response = new StringBuilder();
            HttpURLConnection con = (HttpURLConnection) url.openConnection();
            con.setRequestProperty("User-Agent", "Mozilla/5.0");
            BufferedReader in = new BufferedReader(new InputStreamReader(con.getInputStream()));
            String inputLine;
            while ((inputLine = in.readLine()) != null)
            {
                response.append(inputLine);
            }
            in.close();
            String output = response.toString();

            Log.i(TAG, "onHandleWork: " + output);

            translatedText.postValue(output);//here I am updating data
        }
        catch (IOException e)
        {
            Log.i(TAG, "onHandleWork: ERROR");
        }
    }

    @Override
    public void onDestroy()
    {
        Log.d(TAG, "onDestroy");
        super.onDestroy();
    }

    @Override
    public boolean onStopCurrentWork()
    {
        Log.d(TAG, "onStopCurrentWork");
        return super.onStopCurrentWork();
    }
}

Activity _main.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical">


    <EditText
        android:id="@+id/input"
        android:layout_width="match_parent"
        android:layout_height="100dp"
        android:hint="input"
        android:textSize="24sp" />


    <Button
        android:id="@+id/translateButton"
        android:layout_width="175dp"
        android:layout_height="67dp"
        android:background="#FF9800"
        android:onClick="translate"
        android:text="translateButton"
        android:textSize="30sp" />


    <TextView
        android:id="@+id/translatedText"
        android:layout_width="305dp"
        android:layout_height="215dp"
        android:background="#FDDB73"
        android:scrollY="500dp"
        android:scrollbarAlwaysDrawVerticalTrack="true"
        android:scrollbarStyle="outsideOverlay"
        android:scrollHorizontally="false"
        android:shadowColor="#FFFFFF"
        android:text="translated"
        android:textSize="24sp" />


</LinearLayout>

我已经对此进行了测试，当我尝试翻译时似乎可以正常工作 School我收到了 स्कूल .