Ant example source code file (ChangeLogParser.java)

This example Ant source code file (ChangeLogParser.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

cvsentry, cvsentry, date, get_comment, get_date, get_date, get_file, get_file, get_previous_rev, get_revision, hashtable, simpledateformat, string, string, text, util

The ChangeLogParser.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.cvslib;

import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.Enumeration;
import java.util.Hashtable;
import java.util.Locale;
import java.util.TimeZone;

/**
 * A class used to parse the output of the CVS log command.
 *
 */
class ChangeLogParser {
    //private static final int GET_ENTRY = 0;
    private static final int GET_FILE = 1;
    private static final int GET_DATE = 2;
    private static final int GET_COMMENT = 3;
    private static final int GET_REVISION = 4;
    private static final int GET_PREVIOUS_REV = 5;

// FIXME formatters are not thread-safe

    /** input format for dates read in from cvs log */
    private static final SimpleDateFormat INPUT_DATE
        = new SimpleDateFormat("yyyy/MM/dd HH:mm:ss", Locale.US);
    /**
     * New formatter used to parse CVS date/timestamp.
     */
    private static final SimpleDateFormat CVS1129_INPUT_DATE =
        new SimpleDateFormat("yyyy-MM-dd HH:mm:ss Z", Locale.US);

    static {
        TimeZone utc = TimeZone.getTimeZone("UTC");
        INPUT_DATE.setTimeZone(utc);
        CVS1129_INPUT_DATE.setTimeZone(utc);
    }

    //The following is data used while processing stdout of CVS command
    private String file;
    private String date;
    private String author;
    private String comment;
    private String revision;
    private String previousRevision;

    private int status = GET_FILE;

    /** rcs entries */
    private final Hashtable entries = new Hashtable();

    /**
     * Get a list of rcs entries as an array.
     *
     * @return a list of rcs entries as an array
     */
    public CVSEntry[] getEntrySetAsArray() {
        final CVSEntry[] array = new CVSEntry[ entries.size() ];
        int i = 0;
        for (Enumeration e = entries.elements(); e.hasMoreElements();) {
            array[i++] = (CVSEntry) e.nextElement();
        }
        return array;
    }

    /**
     * Receive notification about the process writing
     * to standard output.
     * @param line the line to process
     */
    public void stdout(final String line) {
        switch(status) {
            case GET_FILE:
                // make sure attributes are reset when
                // working on a 'new' file.
                reset();
                processFile(line);
                break;
            case GET_REVISION:
                processRevision(line);
                break;

            case GET_DATE:
                processDate(line);
                break;

            case GET_COMMENT:
                processComment(line);
                break;

            case GET_PREVIOUS_REV:
                processGetPreviousRevision(line);
                break;

            default:
                // Do nothing
                break;
        }
    }

    /**
     * Process a line while in "GET_COMMENT" state.
     *
     * @param line the line
     */
    private void processComment(final String line) {
        final String lineSeparator = System.getProperty("line.separator");
        if (line.equals(
                "=============================================================================")) {
            //We have ended changelog for that particular file
            //so we can save it
            final int end
                = comment.length() - lineSeparator.length(); //was -1
            comment = comment.substring(0, end);
            saveEntry();
            status = GET_FILE;
        } else if (line.equals("----------------------------")) {
            final int end
                = comment.length() - lineSeparator.length(); //was -1
            comment = comment.substring(0, end);
            status = GET_PREVIOUS_REV;
        } else {
            comment += line + lineSeparator;
        }
    }

    /**
     * Process a line while in "GET_FILE" state.
     *
     * @param line the line to process
     */
    private void processFile(final String line) {
        if (line.startsWith("Working file:")) {
            file = line.substring(14, line.length());
            status = GET_REVISION;
        }
    }

    /**
     * Process a line while in "REVISION" state.
     *
     * @param line the line to process
     */
    private void processRevision(final String line) {
        if (line.startsWith("revision")) {
            revision = line.substring(9);
            status = GET_DATE;
        } else if (line.startsWith("======")) {
            //There were no revisions in this changelog
            //entry so lets move onto next file
            status = GET_FILE;
        }
    }

    /**
     * Process a line while in "DATE" state.
     *
     * @param line the line to process
     */
    private void processDate(final String line) {
        if (line.startsWith("date:")) {
            // The date format is using a - format since 1.12.9 so we have:
            // 1.12.9-: 'date: YYYY/mm/dd HH:mm:ss;  author: name;'
            // 1.12.9+: 'date: YYYY-mm-dd HH:mm:ss Z;  author: name'
            int endOfDateIndex = line.indexOf(';');
            date = line.substring("date: ".length(), endOfDateIndex);

            int startOfAuthorIndex = line.indexOf("author: ", endOfDateIndex + 1);
            int endOfAuthorIndex = line.indexOf(';', startOfAuthorIndex + 1);
            author = line.substring("author: ".length() + startOfAuthorIndex, endOfAuthorIndex);

            status = GET_COMMENT;

            //Reset comment to empty here as we can accumulate multiple lines
            //in the processComment method
            comment = "";
        }
    }

    /**
     * Process a line while in "GET_PREVIOUS_REVISION" state.
     *
     * @param line the line to process
     */
    private void processGetPreviousRevision(final String line) {
        if (!line.startsWith("revision ")) {
            throw new IllegalStateException("Unexpected line from CVS: "
                + line);
        }
        previousRevision = line.substring("revision ".length());

        saveEntry();

        revision = previousRevision;
        status = GET_DATE;
    }

    /**
     * Utility method that saves the current entry.
     */
    private void saveEntry() {
        final String entryKey = date + author + comment;
        CVSEntry entry;
        if (!entries.containsKey(entryKey)) {
            Date dateObject = parseDate(date);
            entry = new CVSEntry(dateObject, author, comment);
            entries.put(entryKey, entry);
        } else {
            entry = (CVSEntry) entries.get(entryKey);
        }

        entry.addFile(file, revision, previousRevision);
    }

    /**
     * Parse date out from expected format.
     *
     * @param date the string holding date
     * @return the date object or null if unknown date format
     */
    private Date parseDate(final String date) {
        try {
            return INPUT_DATE.parse(date);
        } catch (ParseException e) {
            try {
                return CVS1129_INPUT_DATE.parse(date);
            } catch (ParseException e2) {
                throw new IllegalStateException("Invalid date format: " + date);
            }
        }
    }

    /**
     * Reset all internal attributes except status.
     */
    public void reset() {
        this.file = null;
        this.date = null;
        this.author = null;
        this.comment = null;
        this.revision = null;
        this.previousRevision = null;
    }
}