Could not find method问题解决

有时候需要把代码制作成jar包放入到项目中，如果只是一个普通的java文件导入系统都是没有问题的，但是很有可能需要将service导出jar包到，由系统启动。

1.通常只需要修改SystemService.java，比如jar包为AutoService_v0.1.jar，把该文件拷贝到framework/base/services/java/目录下。

2.修改framework/base/services/java目录下的Android.mk文件，这样才会编译到系统，通常都是编译到services.java里面，这不是绝对的。

LOCAL_PATH:= $(call my-dir)

include $(CLEAR_VARS)

LOCAL_PREBUILT_STATIC_JAVA_LIBRARIES := AutoService:AutoService_v0.1.jar

include $(BUILD_MULTI_PREBUILT)

# the library

# ============================================================

include $(CLEAR_VARS)

LOCAL_SRC_FILES := \

            $(call all-subdir-java-files) \

        com/android/server/EventLogTags.logtags \

        com/android/server/am/EventLogTags.logtags

LOCAL_SRC_FILES += $(call all-Iaidl-files-under,com)

LOCAL_MODULE:= services

LOCAL_JAVA_LIBRARIES := android.policy conscrypt telephony-common AutoService

include $(BUILD_JAVA_LIBRARY)

include $(BUILD_DROIDDOC)

3.启动autoservice，这时需要修改SystemService.java，修改如下。

 

4.最后是编译，我们可以用mmm方式进行编译，这样会节省编译时间。

mmm framework/base/services/java

  mmm编译生成services.jar文件，把该文件push到机器的/system/framework目录下，重启机器。也许你会有很大的惊喜，也许会让你失望。不过没关系，办法总是有的。

 

5.下面来看看错误信息

 

D/SensorService( 2614): nuSensorService thread starting...

I/dalvikvm( 2614): Could not find method com.semisky.autoservice.services.AutoService.getInstance, referenced from method com.android.server.ServerThread.initAndLoop

W/dalvikvm( 2614): VFY: unable to resolve static method 14434: Lcom/semisky/autoservice/services/AutoService;.getInstance ()Lcom/semisky/autoservice/services/AutoService;

D/dalvikvm( 2614): VFY: replacing opcode 0x71 at 0x0753

I/installd( 2253): new connection

...

...

I/SystemServer( 2614): Print AutoService

W/SystemServer( 2614): ***********************************************

F/SystemServer( 2614): BOOT FAILURE starting AutoService

F/SystemServer( 2614): java.lang.NoClassDefFoundError: com.semisky.autoservice.services.AutoService

F/SystemServer( 2614):     at com.android.server.ServerThread.initAndLoop(SystemServer.java:817)

F/SystemServer( 2614):     at com.android.server.SystemServer.main(SystemServer.java:1191)

F/SystemServer( 2614):     at java.lang.reflect.Method.invokeNative(Native Method)

F/SystemServer( 2614):     at java.lang.reflect.Method.invoke(Method.java:515)

F/SystemServer( 2614):     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:779)

F/SystemServer( 2614):     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:595)

F/SystemServer( 2614):     at dalvik.system.NativeStart.main(Native Method)

 

上面的错误信息让人头痛，从字面意思来看说是找不到com.semisky.autoservice.services.AutoService.getInstance方法，其实AutoService里面是有getInstance方法的。

6.解决办法

将Android.mk文件改成如下，重新编译push到机器上，解决此问题。

LOCAL_PATH:= $(call my-dir)

include $(CLEAR_VARS)

LOCAL_PREBUILT_STATIC_JAVA_LIBRARIES := AutoService:AutoService_v0.1.jar

include $(BUILD_MULTI_PREBUILT)

# the library

# ============================================================

include $(CLEAR_VARS)

LOCAL_SRC_FILES := \

            $(call all-subdir-java-files) \

        com/android/server/EventLogTags.logtags \

        com/android/server/am/EventLogTags.logtags

LOCAL_SRC_FILES += $(call all-Iaidl-files-under,com)

LOCAL_MODULE:= services

LOCAL_JAVA_LIBRARIES := android.policy conscrypt telephony-common

LOCAL_STATIC_JAVA_LIBRARIES := AutoService

include $(BUILD_JAVA_LIBRARY)

include $(BUILD_DROIDDOC)