07-18 12:04:57.413: E/AndroidRuntime(4448): FATAL EXCEPTION: main
07-18 12:04:57.413: E/AndroidRuntime(4448): java.lang.RuntimeException:
Unable to instantiate application com.txrj.sms.activity.TxrjApplication: java.lang.NullPointerException
07-18 12:04:57.413: E/AndroidRuntime(4448): at android.app.LoadedApk.makeApplication(LoadedApk.java:482)
07-18 12:04:57.413: E/AndroidRuntime(4448): at android.app.ActivityThread.handleBindApplication(ActivityThread.java:3955)
07-18 12:04:57.413: E/AndroidRuntime(4448): at android.app.ActivityThread.access$1300(ActivityThread.java:128)
07-18 12:04:57.413: E/AndroidRuntime(4448): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1199)
07-18 12:04:57.413: E/AndroidRuntime(4448): at android.os.Handler.dispatchMessage(Handler.java:99)
07-18 12:04:57.413: E/AndroidRuntime(4448): at android.os.Looper.loop(Looper.java:137)
07-18 12:04:57.413: E/AndroidRuntime(4448): at android.app.ActivityThread.main(ActivityThread.java:4517)
07-18 12:04:57.413: E/AndroidRuntime(4448): at java.lang.reflect.Method.invokeNative(Native Method)
07-18 12:04:57.413: E/AndroidRuntime(4448): at java.lang.reflect.Method.invoke(Method.java:511)
07-18 12:04:57.413: E/AndroidRuntime(4448): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:993)
07-18 12:04:57.413: E/AndroidRuntime(4448): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:760)
07-18 12:04:57.413: E/AndroidRuntime(4448): at dalvik.system.NativeStart.main(Native Method)
07-18 12:04:57.413: E/AndroidRuntime(4448): Caused by: java.lang.NullPointerException
07-18 12:04:57.413: E/AndroidRuntime(4448): at android.app.LoadedApk.initializeJavaContextClassLoader(LoadedApk.java:362)
07-18 12:04:57.413: E/AndroidRuntime(4448): at android.app.LoadedApk.getClassLoader(LoadedApk.java:305)
07-18 12:04:57.413: E/AndroidRuntime(4448): at android.app.LoadedApk.makeApplication(LoadedApk.java:474)
07-18 12:04:57.413: E/AndroidRuntime(4448): ... 11 more
来源：https://www.cnblogs.com/fengzhblog/p/3199013.html