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#Android ndk sample code how to#
#Android ndk sample code apk#
#Android ndk sample code android#
#Android ndk sample code code#

A simple bash script with Ant is enough to make it work!

#Android ndk sample code android#

HelloJni is the main Activity class name concatenated to the main package.īecause Android SDK, NDK, and their open source bricks are not bound to Eclipse or any specific IDE, creating an automated build chain or setting up a continuous integration server becomes possible. Command parameters passed in step 8 come from the Android manifest: is the package name and.

#Android ndk sample code code#

JNI is a standard framework that allows Java code to explicitly call native C/C++ code with a dedicated API.įinally, we have launched HelloJni on our device from an Android shell ( adb shell) with the am Activity Manager command. Both sides of the application, the native and the Java one, communicate through Java Native Interface. This library simply returns a character string to the Java part of the application on request. We have also compiled our first native C library (also called module) using the ndk-build command.

We have compiled, packaged, and deployed an official NDK sample application with Ant and SDK command-line tools.

Finally, look at your development device.

Command parameters come from the Android manifest: Command am allows to start Android activities, services or sending intents (that is, inter-activity messages) from command line. To do so, use am, the Android Activity Manager.

From this shell, launch HelloJni application on your device or emulator.

ADB shell is similar to shells that can be found on the Linux systems:

Launch a shell session using adb (or adb.exe on Windows).

The result should look like the following extract:

Following is only a partial extract of the output: Among other things, Ant runs javac to compile Java code, AAPT to package the application with its resources, and finally ADB to deploy it on the development device. All these steps can be performed in one command, thanks to Ant build automation tool.

#Android ndk sample code apk#

Compile, package, and install the final HelloJni APK (an Android application package).

Make sure your Android development device or emulator is connected and running.

Command ndk-build sets up the compilation toolchain for native C/ C++ code and calls automatically GCC version featured with the NDK.

Build libhello-jni native library with ndk-build, which is a wrapper Bash script around Make.

(Move the mouse over the image to enlarge.)

#Android ndk sample code how to#

These files describe how to compile and package an Android application:

Create Ant build file and all related configuration files automatically using android command ( android.bat on Windows).

All the following steps have to performed from this directory:

Go to hello-jni sample directory inside the Android NDK.

Open a command-line prompt (or Cygwin prompt on Windows).

Let's compile and deploy HelloJni project from command line using Ant: Time for action – compiling and deploying hellojni sample So why not compile and deploy elementary samples provided by the Android NDK first to see it in action? To get started, I propose to run HelloJni, a sample application which retrieves a character string defined inside a native C library into a Java activity (an activity in Android being more or less equivalent to an application screen). So, since our development environment is set up, we can now get our hands dirty and start manipulating all these utilities to create, compile, and deploy projects which include native code.Ĭompiling and deploying NDK sample applications I guess you cannot wait anymore to test your new development environment. Theses bricks are cemented by the Android Development Kits (SDK and NDK) and their set of new tools: Android Debug Bridge (ADB), Android Asset Packaging Tool (AAPT), Activity Manager (AM), ndk-build, and so on.

Indeed, that is a real strength Android is based on open source bricks which have matured for years. Depending on your background, some of these names may sound familiar to your ears. Eclipse, GCC, Ant, Bash, Shell, Linux-any new Android programmer needs to deal with this technologic ecosystem. (Discover the native side of Android and inject the power of C/C++ in your applications with this book and ebook)īy the end of this article, you should know how to start up a new Android native project on your own.Ī man with the most powerful tools in hand is unarmed without the knowledge of their usage.

Interface Java to C/C++ through Java Native Interfaces (in short JNI).Create our first own hybrid multi-language project using Eclipse.Discover additional tools like AM to manage activities and AAPT to package applications.Learn in more detail about ADB, the Android Debug Bridge, to control a development device.Compile and deploy official sample applications from the Android NDK with Ant build tool and native code compiler ndk-build.In this article by Sylvain Ratabouil, author of Android NDK Beginner’s Guide we are going to do the following: