crontabparser.java

jcrontab是一个定时器开源项目包 目前提供存取文件或数据库, 把执行结果寄发 email, 简单地设置在 Tomcat, Resin, Jetty 及 JBoss 之上, 更是可以取代 cron

/**
 *  This file is part of the jcrontab package
 *  Copyright (C) 2001-2003 Israel Olalla
 *
 *  This library is free software; you can redistribute it and/or
 *  modify it under the terms of the GNU Lesser General Public
 *  License as published by the Free Software Foundation; either
 *  version 2 of the License, or (at your option) any later version.
 *
 *  This library is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 *  Lesser General Public License for more details.
 *
 *  You should have received a copy of the GNU Lesser General Public
 *  License along with this library; if not, write to the Free
 *  Software Foundation, Inc., 59 Temple Place, Suite 330, Boston,
 *  MA 02111-1307, USA
 *
 *  For questions, suggestions:
 *
 *  [e-mail]
 *
 */
package org.jcrontab.data;

import java.util.StringTokenizer;

/** This class parses a Line and returns CrontabEntryBean. This class
 * is done to do more modular and eficient 
 * @author $Author: iolalla $
 * @version $Revision: 1.12 $
 */

public class CrontabParser  {

	/**
	 * Parses a string describing this time table entry and sets the 
	 * neded variables in order to build a CrontabEntry.
	 * Crontab Line usually something similar to:
	 * * * * * * org.jcrontab.jcrontab
	 * @param entry the line to parse
	 * @throws CrontabEntryException Error parsing the string
	 */    
    public CrontabEntryBean marshall(String entry) 
			throws CrontabEntryException {
		boolean[] bHours = new boolean[24];
        boolean[] bMinutes = new boolean[60];
        boolean[] bMonths = new boolean[12];
        boolean[] bDaysOfWeek = new boolean[7];
        boolean[] bDaysOfMonth = new boolean[31];

        CrontabEntryBean ceb = new CrontabEntryBean();
        
        StringTokenizer tokenizer = new StringTokenizer(entry);
        
        int numTokens = tokenizer.countTokens();
        for(int i = 0; tokenizer.hasMoreElements(); i++) {
            String token = tokenizer.nextToken();
            switch(i) {
                case 0:     // Minutes
                    parseToken(token,bMinutes,false);
					ceb.setBMinutes(bMinutes);
					ceb.setMinutes(token);
                    break;
                case 1:     // Hours
                    parseToken(token,bHours,false);
					ceb.setBHours(bHours);
					ceb.setHours(token);
                    break;
                case 2:     // Days of month
                    parseToken(token,bDaysOfMonth,true);
					ceb.setBDaysOfMonth(bDaysOfMonth);
					ceb.setDaysOfMonth(token);
                    break;
                case 3:     // Months
                    parseToken(token,bMonths,true);
					ceb.setBMonths(bMonths);
					ceb.setMonths(token);
                    break;
                case 4:     // Days of week
                    parseToken(token,bDaysOfWeek,false);
					ceb.setBDaysOfWeek(bDaysOfWeek);
					ceb.setDaysOfWeek(token);
                    break;
                case 5:     // Name of the class
					String className, methodName;
                    try {
                        int index = token.indexOf("#");
                        if(index > 0) {
                        StringTokenizer tokenize = new StringTokenizer(token, "#");
                        className = tokenize.nextToken();
                        methodName = tokenize.nextToken();
						ceb.setClassName(className);
						ceb.setMethodName(methodName);
                        } else {
                            className=token;
							ceb.setClassName(className);
                        }
                    } catch (Exception e) {
                        throw new CrontabEntryException(entry);
                    }
                    break;
                case 6:     // Extra Information
                    String[] extraInfo = new String[numTokens - 6];
                    boolean bextraInfo = true;
                    for(extraInfo[i - 6] = token; tokenizer.hasMoreElements(); 
                        extraInfo[i - 6] = tokenizer.nextToken()) {
                        i++;
                    }
					ceb.setBExtraInfo(bextraInfo);
					ceb.setExtraInfo(extraInfo);
                    break;
                default:
                    break;
            }
        }
        
        // At least 6 token
        if(numTokens<6) {
            throw new CrontabEntryException("The number of items is < 6 at " + entry);
        }
		
		return ceb;
    }
        
    /** 
     * Parses a string describing this time table entry
     * @return String describing the time table entry usuarlly something like:
     * * * * * * org.jcrontab.jcrontab
     * @throws CrontabEntryException Error parsing the string
     */    
    public String unmarshall(CrontabEntryBean ceb) throws CrontabEntryException {
        final StringBuffer sb = new StringBuffer();
        sb.append(ceb.getMinutes() + " ");
        sb.append(ceb.getHours() + " ");
        sb.append(ceb.getDaysOfMonth() + " ");
        sb.append(ceb.getMonths() + " ");
        sb.append(ceb.getDaysOfWeek() + " ");
        if ("".equals(ceb.getMethodName())) {
			sb.append(ceb.getClassName() + " ");
        } else {
            sb.append(ceb.getClassName() + "#" + ceb.getMethodName() + " ");
        }
		String[] extraInfo = ceb.getExtraInfo();
        if (extraInfo != null) {               
            for (int i = 0; i < extraInfo.length ; i++) {
		sb.append(extraInfo[i] + " ");
	     }
        }
        return sb.toString();
        
    }
        
    /** 
     * Parses a token and fills the array of booleans that represents this 
     * CrontabEntryBean
     * @param token String to parser usually smth like [ * , 2-3 , 2,3,4 ,4/5 ]
     * @param arrayBool this array is the most efficient way to compare entries
     * @param bBeginInOne says if the array begins in 0 or in 1  
     * @throws CrontabEntryException Error parsing the string
     */    

    public void parseToken(String token, boolean[] arrayBool, 
    	boolean bBeginInOne) 
                    throws CrontabEntryException {
        // This line initializes all the array of booleans instead of doing so
        // in the CrontabEntryBean Constructor.               
        // for (int i = 0; i < arrayBool.length ; i++) arrayBool[i]=false;
        
        int i;
        int index;
        int each=1;
        try {
        	// Look for step first
			index = token.indexOf("/");
			if(index > 0) {
				each = Integer.parseInt(token.substring(index + 1));
				token=token.substring(0,index);
			}
        	
            if(token.equals("*")) {
                for(i=0; i<arrayBool.length; i+=each) {
                    arrayBool[i] = true;
                }
                return;
            }

            index = token.indexOf(",");
            if(index > 0) {
                StringTokenizer tokenizer = new StringTokenizer(token, ",");
                while(tokenizer.hasMoreTokens()) {
                    parseToken(tokenizer.nextToken(), arrayBool, bBeginInOne);
                }
                return;
            }
            
            index = token.indexOf("-");
            if(index > 0) {
                int start = Integer.parseInt(token.substring(0, index));
                int end = Integer.parseInt(token.substring(index + 1));

                if(bBeginInOne) {
                    start--;
                    end--;
                }

                for(int j=start; j<=end; j+=each)
                    arrayBool[j] = true;
                return;
            }
            
                int iValue = Integer.parseInt(token);
                if(bBeginInOne) {
                    iValue--;
                }
                arrayBool[iValue] = true;
                return;
        } catch (Exception e) {
            throw new CrontabEntryException( "Smth was wrong with " + token );
        }
    }
}