java - 请有人帮助我，当我单击 Bind 并给我这个错误时，我的项目崩溃了，nullpointexception

Question

错误

java.lang.NullPointerException: Attempt to invoke virtual method 'android.content.ComponentName android.content.Intent.getComponent()' on a null object reference
    at android.app.ContextImpl.validateServiceIntent(ContextImpl.java:1725)
    at android.app.ContextImpl.bindServiceCommon(ContextImpl.java:1904)
    at android.app.ContextImpl.bindService(ContextImpl.java:1829)
    at android.content.ContextWrapper.bindService(ContextWrapper.java:774)
    at android.content.ContextWrapper.bindService(ContextWrapper.java:774)
    at com.codekul.comman.MainActivity.lambda$onCreate$0$MainActivity(MainActivity.java:46)
    at com.codekul.comman.MainActivity$$ExternalSyntheticLambda0.onClick(Unknown Source:2)
    at android.view.View.performClick(View.java:8160)
    at android.widget.TextView.performClick(TextView.java:16222)
    at com.google.android.material.button.MaterialButton.performClick(MaterialButton.java:1119)
    at android.view.View.performClickInternal(View.java:8137)
    at android.view.View.access$3700(View.java:888)
    at android.view.View$PerformClick.run(View.java:30236)
    at android.os.Handler.handleCallback(Handler.java:938)
    at android.os.Handler.dispatchMessage(Handler.java:99)
    at android.os.Looper.loop(Looper.java:246)
    at android.app.ActivityThread.main(ActivityThread.java:8512)
    at java.lang.reflect.Method.invoke(Native Method)
    at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:602)
    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1139)

我的服务

 package com.codekul.comman;import android.app.Service;import android.content.Intent;import android.os.IBinder;import android.os.RemoteException;public class MyService extends Service {
private MyImpl impl = new MyImpl();
@Override
public IBinder onBind(Intent intent) {

    return impl;
}
private class MyImpl extends IComman.Stub{

  @Override
    public int calculate(int num1, int num2) throws RemoteException {
        return num1 + num2;
    }
}                                                                                    
}

这是我用来在客户端绑定主要活动的服务，使用aidl来通信服务器和客户端。

活动主体

<Button
    android:id="@+id/btnBind"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:text="@string/btnBind" />

<Button
    android:id="@+id/btnCalculate"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:text="@string/btnCalculate"/>

当我单击第一个按钮时出现错误。

主要活动

package com.codekul.comman;
import android.annotation.SuppressLint;
import android.content.ComponentName;
import android.content.Intent;
import android.content.ServiceConnection;
import android.content.pm.PackageManager;
import android.content.pm.ResolveInfo;
import android.os.Bundle;
import android.os.IBinder;
import android.os.RemoteException;
import android.util.Log;
import androidx.appcompat.app.AppCompatActivity;
import java.util.List;
public class MainActivity extends AppCompatActivity {





private IComman comman;
private final ServiceConnection serviceCon = new ServiceConnection() {


    @Override
    public void onServiceConnected(ComponentName componentName, IBinder iBinder) {
        comman = IComman.Stub.asInterface(iBinder);
        

    }

    @Override
    public void onServiceDisconnected(ComponentName componentName) {

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

    findViewById(R.id.btnBind).setOnClickListener((view) -> {

        Intent intent = new Intent("com.codekul.service.aidl");
        bindService(convertImplicitToExplicitIntent(intent), serviceCon, BIND_AUTO_CREATE);

});


    findViewById(R.id.btnCalculate).setOnClickListener((view) -> {
        try {
            Log.i("@codekul", "Addition is - " + comman.calculate(10, 100));
        } catch (NullPointerException | RemoteException e) {
            e.printStackTrace();
        }
    });

}

public Intent convertImplicitToExplicitIntent(Intent implicitIntent) {
    PackageManager pm = getPackageManager();
    @SuppressLint("QueryPermissionsNeeded") List<ResolveInfo> resolveInfoList = pm.queryIntentServices(implicitIntent, 0);

    if (resolveInfoList == null || resolveInfoList.size() != 1) {
        return null;
    }

    ResolveInfo serviceInfo = resolveInfoList.get(0);
    ComponentName component = new ComponentName(serviceInfo.serviceInfo.packageName, serviceInfo.serviceInfo.name);
    Intent explicitIntent = new Intent(implicitIntent);
    explicitIntent.setComponent(component);
    return explicitIntent;
}
}

这是我用来调用我的服务的代码，错误指向 binservice。任何人都可以帮助我解决这个错误。

标签： javaandroidaidl