Android : NullpointerException stopping application to proceed [duplicate]

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• What is a Null Pointer Exception, and how do I fix it? 12 answers

10-07 17:28:07.674: E/AndroidRuntime(427): FATAL EXCEPTION: main
10-07 17:28:07.674: E/AndroidRuntime(427): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.calc/com.example.calc.MainActivity}: java.lang.NullPointerException
10-07 17:28:07.674: E/AndroidRuntime(427):  at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2663)
10-07 17:28:07.674: E/AndroidRuntime(427):  at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2679)
10-07 17:28:07.674: E/AndroidRuntime(427):  at android.app.ActivityThread.access$2300(ActivityThread.java:125)
10-07 17:28:07.674: E/AndroidRuntime(427):  at android.app.ActivityThread$H.handleMessage(ActivityThread.java:2033)
10-07 17:28:07.674: E/AndroidRuntime(427):  at android.os.Handler.dispatchMessage(Handler.java:99)
10-07 17:28:07.674: E/AndroidRuntime(427):  at android.os.Looper.loop(Looper.java:123)
10-07 17:28:07.674: E/AndroidRuntime(427):  at android.app.ActivityThread.main(ActivityThread.java:4627)
10-07 17:28:07.674: E/AndroidRuntime(427):  at java.lang.reflect.Method.invokeNative(Native Method)
10-07 17:28:07.674: E/AndroidRuntime(427):  at java.lang.reflect.Method.invoke(Method.java:521)
10-07 17:28:07.674: E/AndroidRuntime(427):  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:868)
10-07 17:28:07.674: E/AndroidRuntime(427):  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:626)
10-07 17:28:07.674: E/AndroidRuntime(427):  at dalvik.system.NativeStart.main(Native Method)
10-07 17:28:07.674: E/AndroidRuntime(427): Caused by: java.lang.NullPointerException
10-07 17:28:07.674: E/AndroidRuntime(427):  at com.example.calc.MainActivity.onCreate(MainActivity.java:43)
10-07 17:28:07.674: E/AndroidRuntime(427):  at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1047)
10-07 17:28:07.674: E/AndroidRuntime(427):  at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2627)
10-07 17:28:07.674: E/AndroidRuntime(427):  ... 11 more
10-07 17:33:07.974: I/Process(427): Sending signal. PID: 427 SIG: 9