android.content.Context.getString中的NPE导致应用程序启动时崩溃
我们有一个非常奇怪的崩溃,它指向系统类。它出现在应用程序启动时 致命异常:java.lang.RuntimeException:无法启动活动 ComponentInfo{com.myapp.android/com.myapp.android.main.BaseMainActivity}: java.lang.RuntimeException:无法创建应用程序 com.myapp.android.main.myapp:java.lang.NullPointerException 在android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2377)上 位于android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2429) 在android.app.ActivityThread.access$800(ActivityThread.java:151) 在android.app.ActivityThread$H.handleMessage(ActivityThread.java:1342) 位于android.os.Handler.dispatchMessage(Handler.java:110) 位于android.os.Looper.loop(Looper.java:193) 位于android.app.ActivityThread.main(ActivityThread.java:5333) 位于java.lang.reflect.Method.Invokenactive(Method.java) 位于java.lang.reflect.Method.invoke(Method.java:515) 在com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run上(ZygoteInit.java:828) 位于com.android.internal.os.ZygoteInit.main(ZygoteInit.java:644) 在dalvik.system.NativeStart.main(NativeStart.java)由java.lang.RuntimeException引起:无法创建应用程序 com.myapp.android.main.myapp:java.lang.NullPointerException 在android.app.LoadedApk.makeApplication(LoadedApk.java:529)上 在android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2292)上 位于android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2429) 在android.app.ActivityThread.access$800(ActivityThread.java:151) 在android.app.ActivityThread$H.handleMessage(ActivityThread.java:1342) 位于android.os.Handler.dispatchMessage(Handler.java:110) 位于android.os.Looper.loop(Looper.java:193) 位于android.app.ActivityThread.main(ActivityThread.java:5333) 位于java.lang.reflect.Method.Invokenactive(Method.java) 位于java.lang.reflect.Method.invoke(Method.java:515) 在com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run上(ZygoteInit.java:828) 位于com.android.internal.os.ZygoteInit.main(ZygoteInit.java:644) 在dalvik.system.NativeStart.main(NativeStart.java)上,由java.lang.NullPointerException引起 位于android.content.Context.getString(Context.java:343) 在com.myapp.android.api.singleton.AppTrackingInstance.initAdjust(AppTrackingInstance.java:114)上 位于com.myapp.android.api.singletons.AppTrackingInstance.(AppTrackingInstance.java:92) 位于com.myapp.android.injection.modules.ApplicationScopeModule.provideAppTrackingInstance(ApplicationScopeModule.java:326) 在com.myapp.android.injection.modules.ApplicationScopeModule$$ModuleAdapter$ProviderAppTrackingInstanceProvideAdapter.get(ApplicationScopeModule$$ModuleAdapter.java:1618) 在com.myapp.android.injection.modules.ApplicationScopeModule$$ModuleAdapter$ProvideAppTrackingInstanceProvideAdapter.get(ApplicationScopeModule$$ModuleAdapter.java:1552)上 at dagger.internal.Linker$SingletonBinding.get(Linker.java:364) 位于com.myapp.android.main.myapp$$InjectAdapter.injectMembers(myapp$$InjectAdapter.java:70) 位于com.myapp.android.main.myapp$$InjectAdapter.injectMembers(myapp$$InjectAdapter.java:23) ObjectGraph$DaggerObjectGraph.inject(ObjectGraph.java:281) 位于com.myapp.android.main.myapp$1.run(myapp.java:57) 位于com.myapp.android.main.myapp.onCreate(myapp.java:51) 在android.app.Instrumentation.callApplicationOnCreate(Instrumentation.java:1007)中 在android.app.LoadedApk.makeApplication(LoadedApk.java:526)上 在android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2292)上 位于android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2429) 在android.app.ActivityThread.access$800(ActivityThread.java:151) 在android.app.ActivityThread$H.handleMessage(ActivityThread.java:1342) 位于android.os.Handler.dispatchMessage(Handler.java:110) 位于android.os.Looper.loop(Looper.java:193) 位于android.app.ActivityThread.main(ActivityThread.java:5333) 位于java.lang.reflect.Method.Invokenactive(Method.java) 位于java.lang.reflect.Method.invoke(Method.java:515) 在com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run上(ZygoteInit.java:828) 位于com.android.internal.os.ZygoteInit.main(ZygoteInit.java:644) 位于dalvik.system.NativeStart.main(NativeStart.java) 我们使用android.content.Context.getString中的NPE导致应用程序启动时崩溃,android,crash,dagger,android-multidex,Android,Crash,Dagger,Android Multidex,我们有一个非常奇怪的崩溃,它指向系统类。它出现在应用程序启动时 致命异常:java.lang.RuntimeException:无法启动活动 ComponentInfo{com.myapp.android/com.myapp.android.main.BaseMainActivity}: java.lang.RuntimeException:无法创建应用程序 com.myapp.android.main.myapp:java.lang.NullPointerException 在android.
dagger1
,我们的应用程序是multidex
-ed
匕首模块:
@Module(
library = true,
injects = {
MyApp.class
}
)
public class ApplicationScopeModule {
private final MyApp application;
public ApplicationScopeModule(MyApp application) {
this.application = application;
}
@Provides
@Singleton
@ForApplication
Context provideApplicationContext() {
return application.getApplicationContext();
}
@Provides
@Singleton
AppTrackingInstance provideAppTrackingInstance(@ForApplication Context context) {
return new AppTrackingInstance(context);
}
}
package com.myapp.android.main;
public class MyApp extends MultiDexApplication {
private ObjectGraph objectGraph;
@Inject
AppTrackingInstance appTrackingInstance;
@Override
public void onCreate() {
super.onCreate();
// workaround for multi-dex enabled projects
// taken from http://frogermcs.github.io/MultiDex-solution-for-64k-limit-in-Dalvik/
// multi-dex separates dex files, and some classes going to additional dex file.
// Additional .dex files are loaded in Application.attachBaseContext(Context) method
// (by MultiDex.install(Context) invokation). It means, that before this moment
// we can’t use classes from them. So i.e. we cannot declare static fields
// with types attached out of main .dex file.
// Otherwise we’ll get java.lang.NoClassDefFoundError.
//
// the issue should be fixed on the Android level
//
new Runnable() {
@Override
public void run() {
initFabric();
objectGraph = ObjectGraph.create(getModules().toArray());
objectGraph.inject(MyApp.this);
appTrackingInstance.trackAppLaunch();
}
}.run();
}
private void initFabric() {
Fabric.with(MyApp.this, new Crashlytics.Builder().core(new CrashlyticsCore.Builder().disabled(BuildConfig.IS_DEBUG_BUILD).build()).build());
}
public List<Object> getModules() {
return Arrays.<Object>asList(new ApplicationScopeModule(this));
}
public ObjectGraph getObjectGraph() {
return objectGraph;
}
}
package com.myapp.android.api.singletons;
public class AppTrackingInstance {
Context context;
public AppTrackingInstance(Context context) {
this.context = context;
initAdjust();
}
private void initAdjust() {
// "broken" context here
String variable = context.getString(R.string.adjust_variable);
}
}
MyApp类:
@Module(
library = true,
injects = {
MyApp.class
}
)
public class ApplicationScopeModule {
private final MyApp application;
public ApplicationScopeModule(MyApp application) {
this.application = application;
}
@Provides
@Singleton
@ForApplication
Context provideApplicationContext() {
return application.getApplicationContext();
}
@Provides
@Singleton
AppTrackingInstance provideAppTrackingInstance(@ForApplication Context context) {
return new AppTrackingInstance(context);
}
}
package com.myapp.android.main;
public class MyApp extends MultiDexApplication {
private ObjectGraph objectGraph;
@Inject
AppTrackingInstance appTrackingInstance;
@Override
public void onCreate() {
super.onCreate();
// workaround for multi-dex enabled projects
// taken from http://frogermcs.github.io/MultiDex-solution-for-64k-limit-in-Dalvik/
// multi-dex separates dex files, and some classes going to additional dex file.
// Additional .dex files are loaded in Application.attachBaseContext(Context) method
// (by MultiDex.install(Context) invokation). It means, that before this moment
// we can’t use classes from them. So i.e. we cannot declare static fields
// with types attached out of main .dex file.
// Otherwise we’ll get java.lang.NoClassDefFoundError.
//
// the issue should be fixed on the Android level
//
new Runnable() {
@Override
public void run() {
initFabric();
objectGraph = ObjectGraph.create(getModules().toArray());
objectGraph.inject(MyApp.this);
appTrackingInstance.trackAppLaunch();
}
}.run();
}
private void initFabric() {
Fabric.with(MyApp.this, new Crashlytics.Builder().core(new CrashlyticsCore.Builder().disabled(BuildConfig.IS_DEBUG_BUILD).build()).build());
}
public List<Object> getModules() {
return Arrays.<Object>asList(new ApplicationScopeModule(this));
}
public ObjectGraph getObjectGraph() {
return objectGraph;
}
}
package com.myapp.android.api.singletons;
public class AppTrackingInstance {
Context context;
public AppTrackingInstance(Context context) {
this.context = context;
initAdjust();
}
private void initAdjust() {
// "broken" context here
String variable = context.getString(R.string.adjust_variable);
}
}
从实现和stacktrace中,我们得到了崩溃原因:
由java.lang.NullPointerException引起
位于android.content.Context.getString(Context.java:343)
这意味着当用户启动应用程序时,Dagger
注入到apptrackingstance
中断的应用程序上下文中。怎么可能呢?
我们广泛使用Dagger
,在许多地方注入这种上下文都没有问题。只有在某些特定情况下(我无法重现),应用程序在启动时由于上下文中断而崩溃
崩溃出现在不同的设备和操作系统版本上,主要出现在4.x操作系统上,但很少出现在某些5.0.2操作系统版本上:
由于它是应用程序启动时的崩溃,我对它进行了很多调查,发现了非常类似的问题(,)
然后我拿了一些测试设备——Nexus4(安卓5.0.1)、三星S3(安卓4.3)——试着重现这个问题:
- 打开有/无internet连接的应用程序
- 打开/关闭应用程序的50倍
- 打开应用程序,从play market卸载,从play market重新安装
@Provides @Singleton AppTrackingInstance provideAppTrackingInstance(@ForApplication Context context) { return new AppTrackingInstance(context); }