Android报java.lang.IllegalAccessException:accesstoclassn

06-27 04:48:02.123: ERROR/AndroidRuntime(787): java.lang.RuntimeException: Unable to instantiate activity ComponentInfo{net.android.surfacetest/net.android.surfacetest.MainActivity}: java.lang.IllegalAccessException: access to class not al

06-27 04:48:02.123: ERROR/AndroidRuntime(787): java.lang.RuntimeException: Unable to instantiate activity ComponentInfo{net.android.surfacetest/net.android.surfacetest.MainActivity}: java.lang.IllegalAccessException: access to class not allowed
06-27 04:48:02.123: ERROR/AndroidRuntime(787): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1569)
06-27 04:48:02.123: ERROR/AndroidRuntime(787): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:1663)
06-27 04:48:02.123: ERROR/AndroidRuntime(787): at android.app.ActivityThread.access$1500(ActivityThread.java:117)
06-27 04:48:02.123: ERROR/AndroidRuntime(787): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:931)
06-27 04:48:02.123: ERROR/AndroidRuntime(787): at android.os.Handler.dispatchMessage(Handler.java:99)
06-27 04:48:02.123: ERROR/AndroidRuntime(787): at android.os.Looper.loop(Looper.java:123)
06-27 04:48:02.123: ERROR/AndroidRuntime(787): at android.app.ActivityThread.main(ActivityThread.java:3683)
06-27 04:48:02.123: ERROR/AndroidRuntime(787): at java.lang.reflect.Method.invokeNative(Native Method)
06-27 04:48:02.123: ERROR/AndroidRuntime(787): at java.lang.reflect.Method.invoke(Method.java:507)
06-27 04:48:02.123: ERROR/AndroidRuntime(787): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:839)
06-27 04:48:02.123: ERROR/AndroidRuntime(787): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:597)
06-27 04:48:02.123: ERROR/AndroidRuntime(787): at dalvik.system.NativeStart.main(Native Method)
06-27 04:48:02.123: ERROR/AndroidRuntime(787): Caused by: java.lang.IllegalAccessException: access to class not allowed
06-27 04:48:02.123: ERROR/AndroidRuntime(787): at java.lang.Class.newInstanceImpl(Native Method)
06-27 04:48:02.123: ERROR/AndroidRuntime(787): at java.lang.Class.newInstance(Class.java:1409)
06-27 04:48:02.123: ERROR/AndroidRuntime(787): at android.app.Instrumentation.newActivity(Instrumentation.java:1021)
06-27 04:48:02.123: ERROR/AndroidRuntime(787): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1561)

Android出现以上是错误日志信息

原因1：Activity没有注册

原因2：包名不匹配

原因3：类不是public的，在报错类的定义前加public即可。

其中原因1和3是最常见的