source: release-kits/shared/ant-tasks/orans/GetFreePath.java@ 16914

import org.apache.tools.ant.*;
import org.apache.tools.ant.taskdefs.*;
import java.io.File;

/**
 * Returns a path, based on the given path, which does not exist on the filesystem
 * If the given path doesn't exist on the system, just returns the path
 * If the given path does exist, return the path appended with "(n)" where
 * where n is the lowest possible integer greater than 1 which would result in a
 * path that does not exist on the file system.
 */
public class GetFreePath extends Task {

    private File path = null;
    private String property = null;

    /**
     * for testing
     */
    public static void main( String[] args ) {

        GetFreePath gfp = new GetFreePath();
        gfp.setPath( new File(args[0]) );
        gfp.setProperty( args[1] );
        gfp.execute();

    }

    public void execute() {

        //check both attributes set
        if ( path == null ) {
            throw new BuildException( "Error - No path specified !!" );
        }

        if ( property == null ) {
            throw new BuildException( "Error - No property specified !!" );
        }

        //find a free path
        File returnPath = new File(path.getPath());
        for ( int i=2; returnPath.exists(); i++ ) {
            returnPath = new File(path.getPath() + "(" + i + ")" );
        }

        //set the found path in the project
        Project pr = getProject();
        if ( pr != null ) {
            pr.setProperty( "property", returnPath.getPath() );
        }
        System.out.println(returnPath.getPath());
        

    }

   
    public void setPath(File path) {
        this.path = path;
    }

    public void setProperty(String property) {
        this.property = property;
    }

}