我正在尝试实施Google Cloud Messaging。当我运行应用程序时，它会抛出异常
10-21 18:46:14.991: E/AndroidRuntime(4817): FATAL EXCEPTION: main
10-21 18:46:14.991: E/AndroidRuntime(4817): java.lang.NoClassDefFoundError: com.google.android.gms.common.GooglePlayServicesUtil
10-21 18:46:14.991: E/AndroidRuntime(4817): at com.corporate.test.HomePage.checkPlayServices(HomePage.java:211)
10-21 18:46:14.991: E/AndroidRuntime(4817): at com.corporate.test.HomePage.onCreate(HomePage.java:140)
10-21 18:46:14.991: E/AndroidRuntime(4817): at android.app.Activity.performCreate(Activity.java:5020)
10-21 18:46:14.991: E/AndroidRuntime(4817): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1080)
10-21 18:46:14.991: E/AndroidRuntime(4817): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2148)
10-21 18:46:14.991: E/AndroidRuntime(4817): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2211)
10-21 18:46:14.991: E/AndroidRuntime(4817): at android.app.ActivityThread.access$600(ActivityThread.java:149)
10-21 18:46:14.991: E/AndroidRuntime(4817): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1300)
10-21 18:46:14.991: E/AndroidRuntime(4817): at android.os.Handler.dispatchMessage(Handler.java:99)
10-21 18:46:14.991: E/AndroidRuntime(4817): at android.os.Looper.loop(Looper.java:153)
10-21 18:46:14.991: E/AndroidRuntime(4817): at android.app.ActivityThread.main(ActivityThread.java:4987)
10-21 18:46:14.991: E/AndroidRuntime(4817): at java.lang.reflect.Method.invokeNative(Native Method)
10-21 18:46:14.991: E/AndroidRuntime(4817): at java.lang.reflect.Method.invoke(Method.java:511)
10-21 18:46:14.991: E/AndroidRuntime(4817): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:821)
10-21 18:46:14.991: E/AndroidRuntime(4817): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:584)
10-21 18:46:14.991: E/AndroidRuntime(4817): at dalvik.system.NativeStart.main(Native Method)
我的活动代码是
import java.io.IOException;
import java.util.concurrent.atomic.AtomicInteger;
import android.annotation.SuppressLint;
import android.app.Activity;
import android.app.Dialog;
import android.content.Context;
import android.content.Intent;
import android.content.SharedPreferences;
import android.content.pm.PackageInfo;
import android.content.pm.PackageManager.NameNotFoundException;
import android.os.AsyncTask;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.view.View.OnClickListener;
import android.view.Window;
import android.widget.Button;
import android.widget.ImageView;
import android.widget.RelativeLayout;
import android.widget.TextView;
import android.widget.Toast;
import com.google.android.gms.common.ConnectionResult;
import com.google.android.gms.common.GooglePlayServicesUtil;
import com.google.android.gms.gcm.GoogleCloudMessaging;
import com.nextra.utils.AppState;
public class HomePage extends Activity {
RelativeLayout mytrips_relative, approval_relative,
view_transations_relative;
Button backViewTransations, continueViewTransactions;
ImageView logout;
final Context context = this;
public String TAG = "HomePage";
boolean isConnected;
/*
* GCM Client Variables
* */
public static final String EXTRA_MESSAGE = "message";
public static final String PROPERTY_REG_ID = "registration_id";
private static final String PROPERTY_APP_VERSION = "appVersion";
private static final int PLAY_SERVICES_RESOLUTION_REQUEST = 9000;
String SENDER_ID = "XXXX";
TextView mDisplay;
GoogleCloudMessaging gcm;
AtomicInteger msgId = new AtomicInteger();
Context contextGCM;
String regid;
@SuppressLint("NewApi")
/*
* GCM Client Variables END
* */
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
requestWindowFeature(Window.FEATURE_NO_TITLE);
setContentView(R.layout.activity_home_page);
/*
* GCM PlayServices On
* */
contextGCM = getApplicationContext();
// Check device for Play Services APK. If check succeeds, proceed with
// GCM registration.
if (checkPlayServices()) {
gcm = GoogleCloudMessaging.getInstance(this);
regid = getRegistrationId(contextGCM);
Log.d("Registration id ", regid + "");
if (regid.isEmpty()) {
registerInBackground();
}
} else {
Log.i(TAG, "No valid Google Play Services APK found.");
}
}
@Override
protected void onResume() {
super.onResume();
// Check device for Play Services APK.
checkPlayServices();
}
/**
* Check the device to make sure it has the Google Play Services APK. If it
* doesn't, display a dialog that allows users to download the APK from the
* Google Play Store or enable it in the device's system settings.
*/
private boolean checkPlayServices() {
int resultCode = GooglePlayServicesUtil
.isGooglePlayServicesAvailable(this);
if (resultCode != ConnectionResult.SUCCESS) {
if (GooglePlayServicesUtil.isUserRecoverableError(resultCode)) {
GooglePlayServicesUtil.getErrorDialog(resultCode, this,
PLAY_SERVICES_RESOLUTION_REQUEST).show();
} else {
Log.i(TAG, "This device is not supported.");
finish();
}
return false;
}
return true;
}
/**
* Stores the registration ID and the app versionCode in the application's
* {@code SharedPreferences}.
*
* @param context
* application's context.
* @param regId
* registration ID
*/
private void storeRegistrationId(Context context, String regId) {
final SharedPreferences prefs = getGcmPreferences(context);
int appVersion = getAppVersion(context);
Log.i(TAG, "Saving regId on app version " + appVersion);
SharedPreferences.Editor editor = prefs.edit();
editor.putString(PROPERTY_REG_ID, regId);
editor.putInt(PROPERTY_APP_VERSION, appVersion);
editor.commit();
}
/**
* Gets the current registration ID for application on GCM service, if there
* is one.
* <p>
* If result is empty, the app needs to register.
*
* @return registration ID, or empty string if there is no existing
* registration ID.
*/
@SuppressLint("NewApi")
private String getRegistrationId(Context context) {
final SharedPreferences prefs = getGcmPreferences(context);
String registrationId = prefs.getString(PROPERTY_REG_ID, "");
if (registrationId.isEmpty()) {
Log.i(TAG, "Registration not found.");
return "";
}
// Check if app was updated; if so, it must clear the registration ID
// since the existing regID is not guaranteed to work with the new
// app version.
int registeredVersion = prefs.getInt(PROPERTY_APP_VERSION,
Integer.MIN_VALUE);
int currentVersion = getAppVersion(context);
if (registeredVersion != currentVersion) {
Log.i(TAG, "App version changed.");
return "";
}
return registrationId;
}
/**
* Registers the application with GCM servers asynchronously.
* <p>
* Stores the registration ID and the app versionCode in the application's
* shared preferences.
*/
private void registerInBackground() {
new AsyncTask<Void, Void, String>() {
@Override
protected String doInBackground(Void... params) {
String msg = "";
try {
if (gcm == null) {
gcm = GoogleCloudMessaging.getInstance(contextGCM);
}
regid = gcm.register(SENDER_ID);
Log.d("registration Id", regid + "");
msg = "Device registered, registration ID=" + regid;
// You should send the registration ID to your server over
// HTTP, so it
// can use GCM/HTTP or CCS to send messages to your app.
sendRegistrationIdToBackend();
// For this demo: we don't need to send it because the
// device will send
// upstream messages to a server that echo back the message
// using the
// 'from' address in the message.
// Persist the regID - no need to register again.
storeRegistrationId(contextGCM, regid);
} catch (IOException ex) {
msg = "Error :" + ex.getMessage();
// If there is an error, don't just keep trying to register.
// Require the user to click a button again, or perform
// exponential back-off.
}
return msg;
}
@Override
protected void onPostExecute(String msg) {
mDisplay.append(msg + "\n");
}
}.execute(null, null, null);
}
@Override
protected void onDestroy() {
super.onDestroy();
}
}
看到我已经安装了Google Play Services并且还完成了构建路径我仍然收到错误。
答案 0 :(得分：1)
我在Android Studio 0.3.1下遇到了同样的错误。在build.gradle文件中，我添加了＃34; play-services＆＃34; （v3.2.0或更高版本）获得：
dependencies {
compile 'com.android.support:support-v4:18.0.0'
compile 'com.google.android.gms:play-services:3.2.+'
}
我必须在最终工作之前重启Android Studio。使用工具＆gt; Android＆gt; SDKManager确保Google Play＆＃34; extras＆＃34;安装。
答案 1 :(得分：1)
我尝试了所有可以找到的建议，至少重新创建了两次图书馆项目。
然后Eclipse内存不足，很有趣，因为我有64 GB的RAM。
我决定重新启动Windows。当一切都恢复时，它只是起作用。 :-P
答案 2 :(得分：0)
检查您是否已导入Google Play服务项目，并将其添加为项目的依赖库。转到导入的项目属性 - ＆gt; Android部分并选中“Is Library”框
然后在项目依赖项时添加它。如果您正在使用Eclipse，请转到您的项目属性 - ＆gt; Android部分和图书馆部分，添加导入的Google Play服务项目。
此外，修复项目属性和清理也可以帮助您。尝试右键单击项目 - ＆gt; Android工具 - ＆gt;修复项目属性。然后，清除您的项目并尝试运行您的项目。
答案 3 :(得分：-2)
当在运行时未找到代码的类时会发生此错误。通常这意味着包装和/或部署代码时出现问题。检查IDE的设置，尝试重建整个项目。