Jeka - FAQ

Author : Jérôme Angibaud
Version : 0.9.0.M11

General
Can def classes be hosted in separate project than the code to build ?
My commandSet class does not compile so I can't invoke any Jeka method as 'help' or 'scaffold#run'. What can I do ?
Compilation
How can I choose the JDK used to compile ?
How can I use Eclipse compiler in Jeka ?
How can I generate Eclipse/Intellij without using Java plugin (JkPluginJava) ?

General

Can def classes be hosted in separate project than the code to build ?

Of course yes. If you prefer that your Jeka code lies in a distinct project, create a Jeka project in a sibling folder and mention where is located the project to build.

...
@Override
protected void setup() {  // project to build lies in a sibling folder. 
      Path projectPath = this.baseDir().resolve("../myProject");   
      java.getProject().setBaseDir(projectPath);
      ...

My commandSet class does not compile so I can't invoke any Jeka method as 'help' or 'scaffold#run'. What can I do ?

You can specify a built-in commandSet class to run. This way, compilation won't occur. For example jeka -CommandClass=JkCommandSet or jeka -CC=JkCommandSet scaffold#run java#".

Compilation

How can I choose the JDK used to compile ?

Jeka uses the JDK it is running on to compile production or test code. If code must be build on a another JDK version, you can specify JDK path for different version. Just mention it as option, for example in your [JEKA HOME]/options.properties file.

jdk.6=/software/jdk6
jdk.7=/software/jdk7
jdk.9=/software/jdk9
...

This way, if one of your project source code is declared to be in a specific Java version, the relevant JDK version will be used automatically to compile it.

How can I use Eclipse compiler in Jeka ?

Jeka can use any JSR199 Java compiler to compile your Java code. Just set the compiler instance you need as :

import org.eclipse.jdt.internal.compiler.tool.EclipseCompiler;

@JkDefClasspath("org.eclipse.jdt.core.compiler:ecj:4.6.1")
public class Build extends JkCommandSet{
    java.getProject()_
        .getCompilation()
             .getCompiler().setCompilerTool(new EclipseCompiler());
}

How can I generate Eclipse/Intellij without using Java plugin (JkPluginJava) ?

Just make your commandSet class implements dev.jeka.core.api.java.project.JkJavaIdeSupport.JkSupplier.