JenkinsFilesHelper.java

package hudson.plugins.scm_sync_configuration;


import jenkins.model.Jenkins;

import java.io.File;

public class JenkinsFilesHelper {

	public static String buildPathRelativeToHudsonRoot(File file){
		File hudsonRoot = Jenkins.getInstance().getRootDir();
		if(!file.getAbsolutePath().startsWith(hudsonRoot.getAbsolutePath())){
			throw new IllegalArgumentException("Err ! File ["+file.getAbsolutePath()+"] seems not to reside in ["+hudsonRoot.getAbsolutePath()+"] !");
		}
		String truncatedPath = file.getAbsolutePath().substring(hudsonRoot.getAbsolutePath().length()+1); // "+1" because we don't need ending file separator
		return truncatedPath.replaceAll("\\\\", "/"); 
	}

    public static File buildFileFromPathRelativeToHudsonRoot(String pathRelativeToHudsonRoot){
        File hudsonRoot = Jenkins.getInstance().getRootDir();
        return new File(hudsonRoot.getAbsolutePath()+File.separator+pathRelativeToHudsonRoot);
    }
}