1、簽名了app，push apk 到/system/app下(push前需要mount下system目錄)，出現錯誤說是找不到對應的lib***.so文件：
“Couldn't load WatchDog from loader dalvik.system.PathClassLoader[dexPath=/system/app/FactoryTest.apk,libraryPath=/data/app-lib/com.starnet.factorytest-1]: findLibrary returned null”
解決：把所需要的庫（在工程libs/armeabi目錄下的.so文件）push到/system/lib/下即可。
而對於安裝到/data/app（正常安裝）目錄下的app不需要手動push所需要的so文件，也不會出現錯誤。
2、我的工程有三個.c文件，設置了生成對應的.so文件
Android.mk文件：
LOCAL_PATH := $(call my-dir)
include $(CLEAR_VARS)
TARGET_PLATFORM := android-3
LOCAL_MODULE := WatchDog
LOCAL_SRC_FILES := WatchDog.c
LOCAL_LDLIBS := -llog
include $(BUILD_SHARED_LIBRARY)
include $(CLEAR_VARS)
TARGET_PLATFORM := android-3
LOCAL_MODULE := Led
LOCAL_SRC_FILES := Led.c
LOCAL_LDLIBS := -llog
include $(BUILD_SHARED_LIBRARY)
include $(CLEAR_VARS)
TARGET_PLATFORM := android-3
LOCAL_MODULE := SerialPort
LOCAL_SRC_FILES := SerialPort.c
LOCAL_LDLIBS := -llog
include $(BUILD_SHARED_LIBRARY)
若是隻生成一個.so文件，只要：
Android.mk文件：
LOCAL_PATH := $(call my-dir)
include $(CLEAR_VARS)
TARGET_PLATFORM := android-3
LOCAL_MODULE := FactoryTest
LOCAL_SRC_FILES := WatchDog.c
Led.c SerialPort.c
LOCAL_LDLIBS := -llog
include $(BUILD_SHARED_LIBRARY)
即可。
3、對於libs下的armeabi、armeabi-v7a、x68文件夾(沒有可以手動添加)、默認下是隻編譯armeabi的。若是要全部編譯，只要在jni文件夾下添加application.mk文件：
Application.mk文件：
APP_ABI := armeabi armeabi-v7a x86
即可。。。