dependendjava.java

Java的面向对象数据库系统的源代码

// You can redistribute this software and/or modify it under the terms of
// the Infozone Software License version 2 published by the Infozone Group
// (http://www.infozone-group.org).
//
// Copyright (C) @year@ by The Infozone Group. All rights reserved.
//
// $Id: DependendJava.java,v 1.1 2002/05/10 08:59:12 per_nyfelt Exp $

package org.infozone.tools.ant;

import org.apache.tools.ant.BuildException;
import org.apache.tools.ant.taskdefs.Java;
import org.apache.tools.ant.Project;

import java.io.File;
import java.io.IOException;

/**
 * ANT cannot handle the dependency of source files from a definition file.
 * This ability is needed if one will generate source files with castor.
 * This module solves this problem.
 *
 * @version $Revision: 1.1 $
 * @author [e-mail]
 */
public class DependendJava extends Java {

    //
    // Data
    //

    /** the filename of the target */
    private	String	_target = null;
    /** the filename or directory the target depends on */
    private	String	_source = null;

    /**
     * Check if the target is older than the source file or not exists.
     * @param target the target
     * @param source the source file
     */
    private boolean isOlder( String source, String target ) throws BuildException {
        File f_src = new File( source );

        if( !(f_src.exists() && (f_src.isFile() || f_src.isDirectory())) )
            throw new BuildException("Source [[" + source + "]] doesn't exists or isn't a regular entry");
    
        File f_dst = new File( target );

        if( !(f_dst.exists()))
            return true; // non existing target is ok

        if ( f_dst.isDirectory() ) {
            target = target + File.separator + ".depend";
            f_dst = new File (target);
            if( !(f_dst.exists()))
                return true; // again, non existing (modified) target is ok
            }

        if( !(f_dst.isFile()) )
            throw new BuildException("Target [[" + target + "]] isn't a regular entry");

        return f_src.lastModified() > f_dst.lastModified();
    }


    /**
     * Touch the target file.
     * @param target the target to touch.
     */
    private void touch( String target ) throws BuildException {
        File f_dst = new File( target );

        // if the target is a directory, modify the target to point to a hidden file
        if( f_dst.exists() ) {
            if ( f_dst.isDirectory() ) {
                target = target + File.separator + ".depend";
                f_dst = new File (target);
            }
        }
        else
            return; // do nothing if target does not exist
            
        if( f_dst.exists() ) {
            f_dst.setLastModified( System.currentTimeMillis() );
        }
        else {
            try {
                // JDK 1.2 dependency :-(
                f_dst.createNewFile();
            } catch (IOException e) {
                // simply ignore this exception
            }
            
        }
    }


    /**
     * Execute the task. this function will be called by the ANT build system.
     * The work will be made by the ANT internal 'Java' task. We create one,
     * give them the needed parameters and execute them.
     */
    public void execute() throws BuildException {
        if( isOlder( _source, _target ) ) {
            super.execute();
            touch( _target );
        }
        else {
            System.out.println("Nothing to be done for this dependency: " + _source + Project.MSG_INFO);
            //log ("Nothing to be done for this dependency: " + _source, Project.MSG_INFO);
        }
    }


    /**
     * @param s The target name.
     */
    public void setTarget( String s ) {
        _target = s;
    }

    /**
     * @param s The file name of the source file
     */
    public void setDependsOn( String s ) {
        _source = s;
    }

}