Java 从GCM获取令牌时出错

MainActivity.java-

package cc.campusconnect.devapp;

import android.content.Intent;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;

import com.google.android.gms.gcm.GoogleCloudMessaging;

public class MainActivity extends AppCompatActivity{

    Button btnRegId;
    EditText etRegId;
    GoogleCloudMessaging gcm;
    String regid;
    String PROJECT_NUMBER;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        btnRegId = (Button) findViewById(R.id.GCMButton);
        System.out.println("Here!");
        etRegId = (EditText) findViewById(R.id.GCMId);
        PROJECT_NUMBER = "507533032900";
        btnRegId.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {

                System.out.println("I am here");
                Intent intent = new Intent(v.getContext(),RegistrationIntentService.class);
                startService(intent);

            }
        });
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.menu_main, menu);
        return true;
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        // Handle action bar item clicks here. The action bar will
        // automatically handle clicks on the Home/Up button, so long
        // as you specify a parent activity in AndroidManifest.xml.
        int id = item.getItemId();

        //noinspection SimplifiableIfStatement
        if (id == R.id.action_settings) {
            return true;
        }

        return super.onOptionsItemSelected(item);
    }
}

包括的其他文件如下：

我的Android清单文件是

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

     <!-- [START gcm_permission] -->
     <uses-permission android:name="com.google.android.c2dm.permission.RECEIVE" />
     <uses-permission android:name="android.permission.WAKE_LOCK" />
     <!-- [END gcm_permission] -->

     <application
         android:allowBackup="true"
         android:icon="@mipmap/ic_launcher"
         android:label="@string/app_name"
         android:theme="@style/AppTheme" >
         <activity
             android:name="cc.campusconnect.devapp.MainActivity"
             android:label="@string/app_name" >
             <intent-filter>
                 <action android:name="android.intent.action.MAIN" />
                 <category android:name="android.intent.category.LAUNCHER" />
             </intent-filter>
         </activity>

         <!-- [START gcm_receiver] -->
         <receiver
             android:name="com.google.android.gms.gcm.GcmReceiver"
             android:exported="true"
             android:permission="com.google.android.c2dm.permission.SEND" >
             <intent-filter>
                 <action android:name="com.google.android.c2dm.intent.RECEIVE" />
                 <category android:name="cc.campusconnect.devapp" />
             </intent-filter>
         </receiver>
         <!-- [END gcm_receiver] -->

         <!-- [START gcm_listener] -->
         <service
             android:name="cc.campusconnect.devapp.MyGcmListenerService"
             android:exported="false" >
             <intent-filter>
                 <action android:name="com.google.android.c2dm.intent.RECEIVE" />
             </intent-filter>
         </service>
         <!-- [END gcm_listener] -->
         <!-- [START instanceId_listener] -->
         <service
             android:name="cc.campusconnect.devapp.MyInstanceIDListenerService"
             android:exported="false">
             <intent-filter>
                 <action android:name="com.google.android.gms.iid.InstanceID"/>
             </intent-filter>
         </service>
         <!-- [END instanceId_listener] -->
         <service
             android:name="cc.campusconnect.devapp.RegistrationIntentService"
             android:exported="false">
             <intent-filter>
                 <action android:name="com.google.android.c2dm.intent.RECEIVE" />
                 <category android:name="cc.campusconnect.devapp" />
             </intent-filter>
             <intent-filter>
                 <action android:name="com.google.android.c2dm.intent.REGISTER" />
                 <category android:name="cc.campusconnect.devapp" />
             </intent-filter>
             <intent-filter>
                 <action android:name="com.google.android.c2dm.intent.REGISTRATION" />
                 <category android:name="cc.campusconnect.devapp" />
             </intent-filter>
         </service>
     </application>

 </manifest>

---

错误是什么？如何解决此问题？

您可以通过在清单文件中添加以下权限来解决此问题：

 <!-- [START gcm_permission] -->
<uses-permission android:name="android.permission.GET_ACCOUNTS" />
<uses-permission android:name="android.permission.WAKE_LOCK" />
<uses-permission android:name="com.google.android.c2dm.permission.RECEIVE" />
<uses-permission android:name="com.mypackage.myapp.permission.C2D_MESSAGE" />
 <!-- [END gcm_permission] -->

相同的错误仍然存在。我使用虚拟设备。这可能是一些错误的原因吗？另外-我还没有在strings.xml中声明R.string.gcm_defaultSenderId（用于registrationtentservice.java）。如果我这样做了，我会得到gradle错误，说double declaration。如果它说这意味着你已经定义了它，那么找到它，并确保发送者id值是正确的，它与项目id、correct？相同，不知怎的，R.string.gcm_defaultSenderId是正确的

 <!-- [START gcm_permission] -->
<uses-permission android:name="android.permission.GET_ACCOUNTS" />
<uses-permission android:name="android.permission.WAKE_LOCK" />
<uses-permission android:name="com.google.android.c2dm.permission.RECEIVE" />
<uses-permission android:name="com.mypackage.myapp.permission.C2D_MESSAGE" />
 <!-- [END gcm_permission] -->