修改了AndroidManifest.xml，设置<application>的属性Android:name="自定义的Aplication"，结果运行Android项目，报下面错误：
08-18 02:27:41.660: D/dalvikvm(649): newInstance failed: Lcom/foxhis/untils/ActivityApplication;.<init>() not accessible to Landroid/app/Instrumentation;
08-18 02:27:41.660: D/AndroidRuntime(649): Shutting down VM
08-18 02:27:41.660: W/dalvikvm(649): threadid=1: thread exiting with uncaught exception (group=0x4001d800)
08-18 02:27:41.680: E/AndroidRuntime(649): FATAL EXCEPTION: main
08-18 02:27:41.680: E/AndroidRuntime(649): Java.lang.RuntimeException:
Unable to instantiate application com.foxhis.untils.ActivityApplication: java.lang.IllegalAccessException: access to constructor not allowed
08-18 02:27:41.680: E/AndroidRuntime(649): at android.app.ActivityThread$PackageInfo.makeApplication(ActivityThread.java:649)
08-18 02:27:41.680: E/AndroidRuntime(649): at android.app.ActivityThread.handleBindApplication(ActivityThread.java:4232)
08-18 02:27:41.680: E/AndroidRuntime(649): at android.app.ActivityThread.access$3000(ActivityThread.java:125)
08-18 02:27:41.680: E/AndroidRuntime(649): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:2071)
08-18 02:27:41.680: E/AndroidRuntime(649): at android.os.Handler.dispatchMessage(Handler.java:99)
08-18 02:27:41.680: E/AndroidRuntime(649): at android.os.Looper.loop(Looper.java:123)
08-18 02:27:41.680: E/AndroidRuntime(649): at android.app.ActivityThread.main(ActivityThread.java:4627)
08-18 02:27:41.680: E/AndroidRuntime(649): at java.lang.reflect.Method.invokeNative(Native Method)
08-18 02:27:41.680: E/AndroidRuntime(649): at java.lang.reflect.Method.invoke(Method.java:521)
08-18 02:27:41.680: E/AndroidRuntime(649): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:868)
08-18 02:27:41.680: E/AndroidRuntime(649): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:626)
08-18 02:27:41.680: E/AndroidRuntime(649): at dalvik.system.NativeStart.main(Native Method)
08-18 02:27:41.680: E/AndroidRuntime(649): Caused by: java.lang.IllegalAccessException: access to constructor not allowed
08-18 02:27:41.680: E/AndroidRuntime(649): at java.lang.Class.newInstanceImpl(Native Method)
08-18 02:27:41.680: E/AndroidRuntime(649): at java.lang.Class.newInstance(Class.java:1429)
08-18 02:27:41.680: E/AndroidRuntime(649): at android.app.Instrumentation.newApplication(Instrumentation.java:957)
08-18 02:27:41.680: E/AndroidRuntime(649): at android.app.Instrumentation.newApplication(Instrumentation.java:942)
08-18 02:27:41.680: E/AndroidRuntime(649): at android.app.ActivityThread$PackageInfo.makeApplication(ActivityThread.java:644)
08-18 02:27:41.680: E/AndroidRuntime(649): ... 11 more
错误提示是，构造方法的权限不对，招拒。
检查了整个Application，才发现，原来有一个无参数的构造方法，被设计成private。
修改其为public即可。
其他：
对于自定义的Application，如果里面定义的参数是，只仅仅该类中使用，则可以定义为private，私有属性。 如果是其他地方也使用，必须定义为public。 类中方法，全部定义为public。