src/main/org/apache/tools/ant/taskdefs/Touch.java

/*
 * The Apache Software License, Version 1.1
 *
 * Copyright (c) 1999 The Apache Software Foundation.  All rights
 * reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 *
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
 *
 * 3. The end-user documentation included with the redistribution, if
 *    any, must include the following acknowlegement:
 *       "This product includes software developed by the
 *        Apache Software Foundation (http://www.apache.org/)."
 *    Alternately, this acknowlegement may appear in the software itself,
 *    if and wherever such third-party acknowlegements normally appear.
 *
 * 4. The names "The Jakarta Project", "Ant", and "Apache Software
 *    Foundation" must not be used to endorse or promote products derived
 *    from this software without prior written permission. For written
 *    permission, please contact apache@apache.org.
 *
 * 5. Products derived from this software may not be called "Apache"
 *    nor may "Apache" appear in their names without prior written
 *    permission of the Apache Group.
 *
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED.  IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR
 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
 * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 * ====================================================================
 *
 * This software consists of voluntary contributions made by many
 * individuals on behalf of the Apache Software Foundation.  For more
 * information on the Apache Software Foundation, please see
 * <http://www.apache.org/>.
 */

package org.apache.tools.ant.taskdefs;

import org.apache.tools.ant.*;

import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.text.DateFormat;
import java.text.ParseException;
import java.util.Date;
import java.util.Locale;

/**
 * Touch a file - corresponds to the Unix touch command.
 *
 * <p>If the file to touch doesn't exist, an empty one is
 * created. Setting the modification time of files is not supported in
 * JDK 1.1.
 *
 * @author <a href="mailto:stefan.bodewig@megabit.net">Stefan Bodewig</a> 
 */
public class Touch extends Task {

    private File file;              // required
    private long millis = -1;
    private String dateTime;

    private static Method setLastModified = null;
    private static Object lockReflection = new Object();

    /**
     * The name of the file to touch.
     */
    public void setFile(File file) {
        this.file = file;
    }

    /**
     * Milliseconds since 01/01/1970 00:00 am.
     */
    public void setMillis(long millis) {
        this.millis = millis;
    }

    /**
     * Date in the format MM/DD/YYYY HH:MM AM_PM.
     */
    public void setDatetime(String dateTime) {
        this.dateTime = dateTime;
    }

    /**
     * Do the work.
     *
     * @exception BuildException Thrown in unrecoverable error.
     */
    public void execute() throws BuildException {
        if (file.exists() && project.getJavaVersion() == Project.JAVA_1_1) {
            log("Cannot change the modification time of "
                + file + " in JDK 1.1",
                Project.MSG_WARN);
            return;
        }
        
        if (dateTime != null) {
            DateFormat df = DateFormat.getDateTimeInstance(DateFormat.SHORT,
                                                           DateFormat.SHORT,
                                                           Locale.US);
            try {
                setMillis(df.parse(dateTime).getTime());
            } catch (ParseException pe) {
                throw new BuildException(pe.getMessage(), pe, location);
            }
        }

        if (millis >= 0 && project.getJavaVersion() == Project.JAVA_1_1) {
            log(file + " will be created but its modification time cannot be set in JDK 1.1",
                Project.MSG_WARN);
        }

        touch();
    }

    /**
     * Does the actual work. Entry point for Untar and Expand as well.
     */
    void touch() throws BuildException {
        if (!file.exists()) {
            log("Creating "+file, Project.MSG_INFO);
            try {
                FileOutputStream fos = new FileOutputStream(file);
                fos.write(new byte[0]);
                fos.close();
            } catch (IOException ioe) {
                throw new BuildException("Could not create "+file, ioe, 
                                         location);
            }
        }

        if (project.getJavaVersion() == Project.JAVA_1_1) {
            return;
        }

        if (setLastModified == null) {
            synchronized (lockReflection) {
                if (setLastModified == null) {
                    try {
                        setLastModified = 
                            java.io.File.class.getMethod("setLastModified", 
                                                         new Class[] {Long.TYPE});
                    } catch (NoSuchMethodException nse) {
                        throw new BuildException("File.setlastModified not in JDK > 1.1?",
                                                 nse, location);
                    }
                }
            }
        }
        
        Long[] times = new Long[1];
        if (millis < 0) {
            times[0] = new Long(System.currentTimeMillis());
        } else {
            times[0] = new Long(millis);
        }

        try {
            log("Setting modification time for "+file, 
                Project.MSG_VERBOSE);

            setLastModified.invoke(file, times);
        } catch (InvocationTargetException ite) {
            Throwable nested = ite.getTargetException();
            throw new BuildException("Exception setting the modification time of "
                                     + file, nested, location);
        } catch (Throwable other) {
            throw new BuildException("Exception setting the modification time of "
                                     + file, other, location);
        }
    }

}