Android.mk and prebuilt static library

Java language used in Android allow to communicate to external libraries written in C language through JNI interface. However is possible to use only dynamics libraries and there is no possibility, for obvious reasons, to use static libraries instead. In case you have a precompiled static library you need to use in your Android app you can create a dynamics as "wrapper" for your static library.
How to develop a dynamics library able to communicate through JNI is not in the main focus of this post. The only useful information available here will be how to create an Android.mk able to include your precompiled static library in a dynamics library project. Basically the major info are the following:

 
LOCAL_PATH := $(call my-dir)

include $(CLEAR_VARS)

LOCAL_MODULE    := MyStaticLibName 
LOCAL_SRC_FILES := MyStaticLib.a

include $(PREBUILT_STATIC_LIBRARY)

include $(CLEAR_VARS)

LOCAL_MODULE    := MyWrapperDynamicsLibName
LOCAL_SRC_FILES := MyWrapperDynamicsLib.c

LOCAL_STATIC_LIBRARIES := MyStaticLibName

include $(BUILD_SHARED_LIBRARY)

As you can see in Android.mk syntax exist a directive called LOCAL_STATIC_LIBRARIES but this name takes a bit misleading. The params to use is not the direct name of your static library but the name assigned to the module referring to the static library itself. Hope this will help.

Comments

Post a Comment

Popular posts from this blog

Access GPIO from Linux user space

Image
GPIO mean "General Purpose Input/Output" and is a special pin present in some chip that can be set as input or output and used to move a signal high or low (in output mode) or to get the signal current status (in input mode). Usually these pin are directly managed by kernel modules but there are an easy way to manage these pins also from user space.
Read more

Android: adb push and read-only file system error

Image
If you want to copy a file from your PC to the connected android device the fasten way is to use adb tool with push command. This command get as params the path of the local file and the remote path to copy in the device. Sometimes, especially if you use adb from Windows or MacOS, and error about read-only file system show up and you can not copy any file.
Read more

Tree in SQL database: The Nested Set Model

Image
Tree structure are very commonly used by all the application who need to manage a large quantity of data. However once have in memory the tree data the application need a way to save them for future use. SQL database can be a good solution but, in this case, we need a way to store data in efficient mode. This post will propose a model called Nested Set.
Read more