问题
I have to use two native libraries: one is my own and the other one is 3rd-party. As long as I used them in separate projects, everything was ok. But now I'm getting the Exception Ljava/lang/UnsatisfiedLinkError.
I'm using Eclipse.
I found out that if I place the existing library in libs/armeabi, Eclipse begins compilation of the native code and it fails. If I rebuild the JNI part from the command line, compilation succeeds but the 3rd party library disappears. Really stupid.
So how do I tell Eclipse to use an existing .so library along with a library that must be built? The libraries are independent.
回答1:
The NDK allows for linking with prebuilt user libraries, using the PREBUILT_SHARED_LIBRARY variable.
Assuming that the library you need to link is librandom.so, create a libs folder in jni subfolder of the project folder:
mkdir -p jni/libs
cp librandom.so jni/libs
Then, just create a jni/libs/Android.mk file:
LOCAL_PATH := $(call my-dir)
include $(CLEAR_VARS)
LOCAL_MODULE := random
LOCAL_SRC_FILES := librandom.so
include $(PREBUILT_SHARED_LIBRARY)
You can create a section for each prebuilt library, all placed in jni/libs.
Next, you just need to include the above file into your jni/Android.mk to get things to work. In the NDK docs, it is recommended that this be done at the end of the Android.mk, rather than the middle:
include $(LOCAL_PATH)/libs/Android.mk
However, you'll need to do this before the module that requires this library.
For linking, you'll need to add the following into the module section that links to the prebuilt library.
LOCAL_SHARED_LIBRARIES := random
Then when you do ndk-build, it will copy this library into libs/armeabi/ before building the module, and you're good to go.
Note: This does not solve problems with required headers. You'll still need to add the location of the headers for the library into the variable LOCAL_C_INCLUDES in the module that requires it.
回答2:
This is what I have done for the moment. I will not accept (in stackoverflow sense) my own (this) answer beause it is unsatisfactory.
I have created a new project and copied all java files there. Then, I copied the .so library from the old project and the 3rd party library into libs/armeabi.
That's monstrous. But it works. For the moment. The worst thing is that the version control is torpedoed.
来源：https://stackoverflow.com/questions/10363021/multiple-my-and-3rd-party-native-libraries-in-android-ndk