Ant example source code file (Tstamp.java)

This example Ant source code file (Tstamp.java) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" ^TM.

Java - Ant tags/keywords

buildexception, buildexception, customformat, customformat, date, day, month, simpledateformat, simpledateformat, string, string, text, unit, units, util, vector

The Tstamp.java source code

/*
 *  Licensed to the Apache Software Foundation (ASF) under one or more
 *  contributor license agreements.  See the NOTICE file distributed with
 *  this work for additional information regarding copyright ownership.
 *  The ASF licenses this file to You under the Apache License, Version 2.0
 *  (the "License"); you may not use this file except in compliance with
 *  the License.  You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 *  Unless required by applicable law or agreed to in writing, software
 *  distributed under the License is distributed on an "AS IS" BASIS,
 *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *  See the License for the specific language governing permissions and
 *  limitations under the License.
 *
 */

package org.apache.tools.ant.taskdefs;

import java.text.SimpleDateFormat;
import java.util.Calendar;
import java.util.Date;
import java.util.Enumeration;
import java.util.HashMap;
import java.util.Locale;
import java.util.Map;
import java.util.NoSuchElementException;
import java.util.StringTokenizer;
import java.util.TimeZone;
import java.util.Vector;
import org.apache.tools.ant.BuildException;
import org.apache.tools.ant.Location;
import org.apache.tools.ant.Project;
import org.apache.tools.ant.Task;
import org.apache.tools.ant.types.EnumeratedAttribute;

/**
 * Sets properties to the current time, or offsets from the current time.
 * The default properties are TSTAMP, DSTAMP and TODAY;
 *
 * @since Ant 1.1
 * @ant.task category="utility"
 */
public class Tstamp extends Task {

    private Vector customFormats = new Vector();
    private String prefix = "";

    /**
     * Set a prefix for the properties. If the prefix does not end with a "."
     * one is automatically added.
     * @param prefix the prefix to use.
     * @since Ant 1.5
     */
    public void setPrefix(String prefix) {
        this.prefix = prefix;
        if (!this.prefix.endsWith(".")) {
            this.prefix += ".";
        }
    }

    /**
     * create the timestamps. Custom ones are done before
     * the standard ones, to get their retaliation in early.
     * @throws BuildException on error.
     */
    public void execute() throws BuildException {
        try {
            Date d = new Date();

            Enumeration i = customFormats.elements();
            while (i.hasMoreElements()) {
                CustomFormat cts = (CustomFormat) i.nextElement();
                cts.execute(getProject(), d, getLocation());
            }

            SimpleDateFormat dstamp = new SimpleDateFormat ("yyyyMMdd");
            setProperty("DSTAMP", dstamp.format(d));

            SimpleDateFormat tstamp = new SimpleDateFormat ("HHmm");
            setProperty("TSTAMP", tstamp.format(d));

            SimpleDateFormat today
                = new SimpleDateFormat ("MMMM d yyyy", Locale.US);
            setProperty("TODAY", today.format(d));

        } catch (Exception e) {
            throw new BuildException(e);
        }
    }

    /**
     * create a custom format with the current prefix.
     * @return a ready to fill-in format
     */
    public CustomFormat createFormat() {
        CustomFormat cts = new CustomFormat();
        customFormats.addElement(cts);
        return cts;
    }

    /**
     * helper that encapsulates prefix logic and property setting
     * policy (i.e. we use setNewProperty instead of setProperty).
     */
    private void setProperty(String name, String value) {
        getProject().setNewProperty(prefix + name, value);
    }

    /**
     * This nested element that allows a property to be set
     * to the current date and time in a given format.
     * The date/time patterns are as defined in the
     * Java SimpleDateFormat class.
     * The format element also allows offsets to be applied to
     * the time to generate different time values.
     * @todo consider refactoring out into a re-usable element.
     */
    public class CustomFormat {
        private TimeZone timeZone;
        private String propertyName;
        private String pattern;
        private String language;
        private String country;
        private String variant;
        private int offset = 0;
        private int field = Calendar.DATE;

        /**
         * Create a format
         */
        public CustomFormat() {
        }

        /**
         *  The property to receive the date/time string in the given pattern
         * @param propertyName the name of the property.
         */
        public void setProperty(String propertyName) {
            this.propertyName = propertyName;
        }

        /**
         * The date/time pattern to be used. The values are as
         * defined by the Java SimpleDateFormat class.
         * @param pattern the pattern to use.
         * @see java.text.SimpleDateFormat
         */
        public void setPattern(String pattern) {
            this.pattern = pattern;
        }

        /**
         * The locale used to create date/time string.
         * The general form is "language, country, variant" but
         * either variant or variant and country may be omitted.
         * For more information please refer to documentation
         * for the java.util.Locale  class.
         * @param locale the locale to use.
         * @see java.util.Locale
         */
        public void setLocale(String locale) {
            StringTokenizer st = new StringTokenizer(locale, " \t\n\r\f,");
            try {
                language = st.nextToken();
                if (st.hasMoreElements()) {
                    country = st.nextToken();
                    if (st.hasMoreElements()) {
                        variant = st.nextToken();
                        if (st.hasMoreElements()) {
                            throw new BuildException("bad locale format",
                                                      getLocation());
                        }
                    }
                } else {
                    country = "";
                }
            } catch (NoSuchElementException e) {
                throw new BuildException("bad locale format", e,
                                         getLocation());
            }
        }

        /**
         * The timezone to use for displaying time.
         * The values are as defined by the Java TimeZone class.
         * @param id the timezone value.
         * @see java.util.TimeZone
         */
        public void setTimezone(String id) {
            timeZone = TimeZone.getTimeZone(id);
        }

        /**
         * The numeric offset to the current time.
         * @param offset the offset to use.
         */
        public void setOffset(int offset) {
            this.offset = offset;
        }

        /**
         * Set the unit type (using String).
         * @param unit the unit to use.
         * @deprecated since 1.5.x.
         *             setUnit(String) is deprecated and is replaced with
         *             setUnit(Tstamp.Unit) to make Ant's
         *             Introspection mechanism do the work and also to
         *             encapsulate operations on the unit in its own
         *             class.
         */
        public void setUnit(String unit) {
            log("DEPRECATED - The setUnit(String) method has been deprecated."
                + " Use setUnit(Tstamp.Unit) instead.");
            Unit u = new Unit();
            u.setValue(unit);
            field = u.getCalendarField();
        }

        /**
         * The unit of the offset to be applied to the current time.
         * Valid Values are
         * <ul>
         *    <li>millisecond
         *    <li>second
         *    <li>minute
         *    <li>hour
         *    <li>day
         *    <li>week
         *    <li>month
         *    <li>year
         * </ul>
         * The default unit is day.
         * @param unit the unit to use.
         */
        public void setUnit(Unit unit) {
            field = unit.getCalendarField();
        }

        /**
         * validate parameter and execute the format.
         * @param project project to set property in.
         * @param date date to use as a starting point.
         * @param location line in file (for errors)
         */
        public void execute(Project project, Date date, Location location) {
            if (propertyName == null) {
                throw new BuildException("property attribute must be provided",
                                         location);
            }

            if (pattern == null) {
                throw new BuildException("pattern attribute must be provided",
                                         location);
            }

            SimpleDateFormat sdf;
            if (language == null) {
                sdf = new SimpleDateFormat(pattern);
            } else if (variant == null) {
                sdf = new SimpleDateFormat(pattern,
                                           new Locale(language, country));
            } else {
                sdf = new SimpleDateFormat(pattern,
                                           new Locale(language, country,
                                                      variant));
            }
            if (offset != 0) {
                Calendar calendar = Calendar.getInstance();
                calendar.setTime(date);
                calendar.add(field, offset);
                date = calendar.getTime();
            }
            if (timeZone != null) {
                sdf.setTimeZone(timeZone);
            }
            Tstamp.this.setProperty(propertyName, sdf.format(date));
        }
    }

    /**
     * set of valid units to use for time offsets.
     */
    public static class Unit extends EnumeratedAttribute {

        private static final String MILLISECOND = "millisecond";
        private static final String SECOND = "second";
        private static final String MINUTE = "minute";
        private static final String HOUR = "hour";
        private static final String DAY = "day";
        private static final String WEEK = "week";
        private static final String MONTH = "month";
        private static final String YEAR = "year";

        private static final String[] UNITS = {
                                                MILLISECOND,
                                                SECOND,
                                                MINUTE,
                                                HOUR,
                                                DAY,
                                                WEEK,
                                                MONTH,
                                                YEAR
                                              };

        private Map calendarFields = new HashMap();

        /** Constructor for Unit enumerated type. */
        public Unit() {
            calendarFields.put(MILLISECOND,
                               new Integer(Calendar.MILLISECOND));
            calendarFields.put(SECOND, new Integer(Calendar.SECOND));
            calendarFields.put(MINUTE, new Integer(Calendar.MINUTE));
            calendarFields.put(HOUR, new Integer(Calendar.HOUR_OF_DAY));
            calendarFields.put(DAY, new Integer(Calendar.DATE));
            calendarFields.put(WEEK, new Integer(Calendar.WEEK_OF_YEAR));
            calendarFields.put(MONTH, new Integer(Calendar.MONTH));
            calendarFields.put(YEAR, new Integer(Calendar.YEAR));
        }

        /**
         * Convert the value to int unit value.
         * @return an int value.
         */
        public int getCalendarField() {
            String key = getValue().toLowerCase();
            Integer i = (Integer) calendarFields.get(key);
            return i.intValue();
        }

        /**
         * Get the valid values.
         * @return the value values.
         */
        public String[] getValues() {
            return UNITS;
        }
    }
}