How to generate apk file programmatically through java code

Question

I need to generate or build an APK file through some Java program where I select the Android source project. Suppose I have a button on a web page. When clicked, it generates an .apk file.

I have seen we can build the APK file through Ant and Gradle. But this runs through the command shell. I don't want to do it in a command shell. I want to write a Java program. Or maybe I can run shell commands through a Java program.

Could anybody guide me on this? Thanks

Thanks for the answers you have provided. For those answers I need to go through Gradle or Ant. I will do that if I have to. But, I am looking for alternatives.

Answer 1

You can use the ANT jars ant.jar and ant-launcher.jar.
In this case the path for build.xml should be fully specified. Call it from your Java class this way:

public class AntTest {
public static void main(String[] args) {
    String build = "D:/xampp/htdocs/aud/TempProject/build.xml";
    generateApkThroughAnt(build);
}
/*
 * Generate APK through ANT API Method
 */
public static void generateApkThroughAnt(String buildPath) {
    File antBuildFile = new File(buildPath);
    Project p = new Project();
    p.setUserProperty("ant.file", antBuildFile.getAbsolutePath());
    DefaultLogger consoleLogger = new DefaultLogger();
    consoleLogger.setErrorPrintStream(System.err);
    consoleLogger.setOutputPrintStream(System.out);
    consoleLogger.setMessageOutputLevel(Project.MSG_INFO);
    p.addBuildListener(consoleLogger);
    BuildException ex = null;
    try {
        p.fireBuildStarted();
        p.init();
        ProjectHelper helper = ProjectHelper.getProjectHelper();
        p.addReference("ant.projectHelper", helper);
        helper.parse(p, antBuildFile);
        p.executeTarget("clean");
        p.executeTarget("release");
    } catch (BuildException e) {
        ex = e;
    } finally {
        p.fireBuildFinished(ex);
    }
   }
   }

To create a build.xml file go to Eclipse=>Your Project=>Right click=>Export=>General=>Ant Buildfiles. After that then you will need to run:

android update project --name <project_name> --target <target_ID> --path <path_to_your_project>