报错堆栈：
java.lang.RuntimeException: Unable to get provider com.vivo.upgrade.library.provider.FileProvider: java.lang.ClassNotFoundException: com.vivo.upgrade.library.provider.FileProvider in loader com.zhangyue.iReader.plugin.d[DexPathList[[zip file "/data/app/com.chaozh.iReader-2.apk"],nativeLibraryDirectories=[/vendor/lib, /system/lib]]]
at android.app.ActivityThread.installProvider(ActivityThread.java:4919)
at android.app.ActivityThread.installContentProviders(ActivityThread.java:4511)
at android.app.ActivityThread.handleBindApplication(ActivityThread.java:4448)
at android.app.ActivityThread.access$1500(ActivityThread.java:140)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1262)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:136)
at android.app.ActivityThread.main(ActivityThread.java:5143)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:515)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:786)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:602)
at dalvik.system.NativeStart.main(Native Method)
Caused by: java.lang.ClassNotFoundException: com.vivo.upgrade.library.provider.FileProvider in loader com.zhangyue.iReader.plugin.d[DexPathList[[zip file "/data/app/com.chaozh.iReader-2.apk"],nativeLibraryDirectories=[/vendor/lib, /system/lib]]]
at com.zhangyue.iReader.plugin.IreaderClassLoader.loadClass(SourceFile:90)
at java.lang.ClassLoader.loadClass(ClassLoader.java:457)
at android.app.ActivityThread.installProvider(ActivityThread.java:4904)
... 12 more
我们先看下activityThread 的源码：
private ContentProviderHolder installProvider(Context context,
ContentProviderHolder holder, ProviderInfo info,
boolean noisy, boolean noReleaseNeeded, boolean stable) {
ContentProvider localProvider = null;
IContentProvider provider;
if (holder == null || holder.provider == null) {
if (DEBUG_PROVIDER || noisy) {
Slog.d(TAG, "Loading provider " + info.authority + ": "
+ info.name);
}
Context c = null;
ApplicationInfo ai = info.applicationInfo;
if (context.getPackageName().equals(ai.packageName)) {
c = context;
} else if (mInitialApplication != null &&
mInitialApplication.getPackageName().equals(ai.packageName)) {
c = mInitialApplication;
} else {
try {
c = context.createPackageContext(ai.packageName,
Context.CONTEXT_INCLUDE_CODE);
} catch (PackageManager.NameNotFoundException e) {
// Ignore
}
}
if (c == null) {
Slog.w(TAG, "Unable to get context for package " +
ai.packageName +
" while loading content provider " +
info.name);
return null;
}
if (info.splitName != null) {
try {
c = c.createContextForSplit(info.splitName);
} catch (NameNotFoundException e) {
throw new RuntimeException(e);
}
}
try {
final java.lang.ClassLoader cl = c.getClassLoader();
LoadedApk packageInfo = peekPackageInfo(ai.packageName, true);
if (packageInfo == null) {
// System startup case.
packageInfo = getSystemContext().mPackageInfo;
}
localProvider = packageInfo.getAppFactory()
.instantiateProvider(cl, info.name);
provider = localProvider.getIContentProvider();
if (provider == null) {
Slog.e(TAG, "Failed to instantiate class " +
info.name + " from sourceDir " +
info.applicationInfo.sourceDir);
return null;
}
if (DEBUG_PROVIDER) Slog.v(
TAG, "Instantiating local provider " + info.name);
// XXX Need to create the correct context for this provider.
localProvider.attachInfo(c, info);
} catch (java.lang.Exception e) {
if (!mInstrumentation.onException(null, e)) {
throw new RuntimeException(
"Unable to get provider " + info.name
+ ": " + e.toString(), e);
}
return null;
}
} else {
很明显报错的地方，在这里
if (!mInstrumentation.onException(null, e)) {
throw new RuntimeException(
"Unable to get provider " + info.name
+ ": " + e.toString(), e);
}
return null;
解决方法就是
自己定义一个mInstrumentation，重写 onException 方法，返回true.表示自己处理。
总结：
很多问题，只有多看源码，才知道原因，毕竟这是源码的地方报了错误。看源码，让人学到很多， 比如ActivityThread 里面，可以看到activity的生命周期。可以看到Application 的onAttch 方法什么时候被调用。
如果你没看过源码，很多问题你无从下手，可以看了源码之后，你回发现，原来很简单。 加油吧。
