Java 更改布局方向时丢失信息

我有一个android应用程序，在java中有蓝牙连接，当我更改布局方向（我已经创建了layout land文件夹）时，布局会正确更改，但我拥有的信息会丢失，收到的所有消息都已消失，当我尝试发送消息时，它会崩溃，并向我显示此异常，就像连接已断开，但仍在运行：

D/AndroidRuntime(29591): Shutting down VM
08-01 10:13:04.499: W/dalvikvm(29591): threadid=1: thread exiting with uncaught exception (group=0x2aac8578)
08-01 10:13:04.519: E/AndroidRuntime(29591): FATAL EXCEPTION: main
08-01 10:13:04.519: E/AndroidRuntime(29591): java.lang.IllegalStateException: Could not execute method of the activity
08-01 10:13:04.519: E/AndroidRuntime(29591):    at android.view.View$1.onClick(View.java:2168)
08-01 10:13:04.519: E/AndroidRuntime(29591):    at android.view.View.performClick(View.java:2552)
08-01 10:13:04.519: E/AndroidRuntime(29591):    at android.widget.CompoundButton.performClick(CompoundButton.java:103)
08-01 10:13:04.519: E/AndroidRuntime(29591):    at android.view.View$PerformClick.run(View.java:9229)
08-01 10:13:04.519: E/AndroidRuntime(29591):    at android.os.Handler.handleCallback(Handler.java:587)
08-01 10:13:04.519: E/AndroidRuntime(29591):    at android.os.Handler.dispatchMessage(Handler.java:92)
08-01 10:13:04.519: E/AndroidRuntime(29591):    at android.os.Looper.loop(Looper.java:138)
08-01 10:13:04.519: E/AndroidRuntime(29591):    at android.app.ActivityThread.main(ActivityThread.java:3701)
08-01 10:13:04.519: E/AndroidRuntime(29591):    at java.lang.reflect.Method.invokeNative(Native Method)
08-01 10:13:04.519: E/AndroidRuntime(29591):    at java.lang.reflect.Method.invoke(Method.java:507)
08-01 10:13:04.519: E/AndroidRuntime(29591):    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:878)
08-01 10:13:04.519: E/AndroidRuntime(29591):    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:636)
08-01 10:13:04.519: E/AndroidRuntime(29591):    at dalvik.system.NativeStart.main(Native Method)
08-01 10:13:04.519: E/AndroidRuntime(29591): Caused by: java.lang.reflect.InvocationTargetException
08-01 10:13:04.519: E/AndroidRuntime(29591):    at java.lang.reflect.Method.invokeNative(Native Method)
08-01 10:13:04.519: E/AndroidRuntime(29591):    at java.lang.reflect.Method.invoke(Method.java:507)
08-01 10:13:04.519: E/AndroidRuntime(29591):    at android.view.View$1.onClick(View.java:2163)
08-01 10:13:04.519: E/AndroidRuntime(29591):    ... 12 more
08-01 10:13:04.519: E/AndroidRuntime(29591): Caused by: java.lang.NullPointerException
08-01 10:13:04.519: E/AndroidRuntime(29591):    at com.example.bluetooth.cochee.BluetoothConexion.escribir(BluetoothConexion.java:350)
08-01 10:13:04.519: E/AndroidRuntime(29591):    at com.example.bluetooth.cochee.AndroidTabsActivity.Comprobar5(AndroidTabsActivity.java:554)
08-01 10:13:04.519: E/AndroidRuntime(29591):    ... 15 more
08-01 10:13:07.429: I/Process(29591): Sending signal. PID: 29591 SIG: 9
08-01 10:13:09.849: W/KeyCharacterMap(29760): Can't open keycharmap file
08-01 10:13:09.849: W/KeyCharacterMap(29760): Error loading keycharmap file '/system/usr/keychars/clearpad.kcm.bin'. hw.keyboards.65541.devname='clearpad'
08-01 10:13:09.849: W/KeyCharacterMap(29760): Using default keymap: /system/usr/keychars/qwerty.kcm.bin

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每次更改方向时，您的活动都会重新启动，因此您需要在其生命周期方法中保存活动的状态：

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配置更改后，您的活动将重新创建，因此不得保留指向活动的链接（内存泄漏）。此外，您还应在onDestroy之前保存信息（应使用onSafeConfigurationChanges方法）。

每次更改方向时，必须将所有信息保存在onPause（）方法中，并在onResume（）中恢复。因为android会重新创建所有活动

读这个