filesource.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.io.BufferedReader;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.IOException;
import java.io.OutputStream;
import java.io.PrintStream;
import java.io.Reader;
import java.util.Vector;
import org.jcrontab.Crontab;

/**
 * This class Is the implementation of DataSource to access 
 * Info in a FileSystem
 * @author $Author: iolalla $
 * @version $Revision: 1.43 $
 */
public class FileSource implements DataSource {
	
	private CrontabParser cp = new CrontabParser();

	private static FileSource instance;
    
	private CrontabEntryBean[] cachedBeans = null;
	
	protected long lastModified;
	
	private String crontab_file = "crontab";
    
    /** 
	* Creates new FileSource 
	*/
	
    protected FileSource() {
			if (Crontab.getInstance().getProperty(
								"org.jcrontab.data.file") == null) 
				Crontab.getInstance().setProperty(
								"org.jcrontab.data.file", crontab_file);
    }	
    /**
	 *	This method returns the singleton is very important to grant
	 *  That only a Thread accesses at a time
	 */
    public synchronized DataSource getInstance() {
		if (instance == null) {
		instance = new FileSource();
		}
		return instance;
    }
	
    /**
	 *	This method searches the given Bean  from the File
	 *  @return CrontabEntryBean beans Array the result of the search
	 *  @param CrontabEntryBean the CrontabEntryBean you want to search
	 *  @throws CrontabEntryException when it can't parse the line correctly
	 *  @throws IOException If it can't access correctly to the File
	 *  @throws DataNotFoundException whe it can't find nothing in the file 
	 */
    public synchronized CrontabEntryBean find(CrontabEntryBean ceb) 
    	throws CrontabEntryException, IOException, DataNotFoundException {
        CrontabEntryBean[] cebra = findAll();
		for (int i = 0; i < cebra.length ; i++) {
			if (cebra[i].equals(ceb)) {
//System.out.println("cebra encontrada : " + cebra[i]);
				return cebra[i];
			}
		}
		throw new DataNotFoundException("Unable to find :" + ceb);
    }

	protected InputStream createCrontabStream(String name)
		throws IOException {
		return new FileInputStream(name);
	}

	protected boolean isChanged(String name) {
            // Don't like those three lines. But are the only way i have to grant
            // It works in any O.S.
		final File filez = new File(name);
		if (lastModified != filez.lastModified()) {
				// This line is added to avoid reading the file if it didn't 
				// change
			lastModified = filez.lastModified();
			return true;
		}
		return false;
	}
   /**
	 *	This method searches all the CrontabEntryBean from the File
	 *  @return CrontabEntryBean beans Array the result of the search
	 *  @throws CrontabEntryException when it can't parse the line correctly
	 *  @throws IOException If it can't access correctly to the File
	 *  @throws DataNotFoundException whe it can't find nothing in the file 
	 */
    public synchronized CrontabEntryBean[] findAll() throws CrontabEntryException, 
			IOException, DataNotFoundException {
                
            boolean[] bSeconds = new boolean[60];
            boolean[] bYears = new boolean[10];
            
	        Vector listOfLines = new Vector();
            Vector listOfBeans = new Vector();
            // Class cla = FileSource.class;
            // BufferedReader input = new BufferedReader(new FileReader(strFileName));
            // This Line allows the crontab to be included in a jar file
            // and accessed from anywhere
            String filename = Crontab.getInstance().getProperty("org.jcrontab.data.file");
            
			if (isChanged(filename)) {
				// open the file
				final InputStream fis = createCrontabStream(filename);
				BufferedReader input = new BufferedReader(
												new InputStreamReader(fis));
				
				String strLine;
				
				while((strLine = input.readLine()) != null){
					//System.out.println(strLine);
					strLine = strLine.trim();
					listOfLines.add(strLine);
				}
				input.close();
					if (listOfLines.size() > 0) {
					for (int i = 0; i < listOfLines.size() ; i++) {
						String strLines = (String)listOfLines.get(i);
						// Skips blank lines and comments
						if(strLines.equals("") || strLines.charAt(0) == '#'){
						} else {
						//System.out.println(strLines);

						CrontabEntryBean entry = cp.marshall(strLines);
                        
                            cp.parseToken("*", bYears, false);
                            entry.setBYears(bYears);
                            entry.setYears("*");
                        
                            cp.parseToken("0", bSeconds, false);
                            entry.setBSeconds(bSeconds);
                            entry.setSeconds("0");
                        
						listOfBeans.add(entry);
						}
					}
					} else {
					throw new DataNotFoundException("No CrontabEntries available");
					}
           
            	int sizeOfBeans = listOfBeans.size();
				if ( sizeOfBeans == 0 ){
					throw new DataNotFoundException("No CrontabEntries available");
				} else {
					CrontabEntryBean[] finalBeans = 
						new CrontabEntryBean[sizeOfBeans];
					for (int i = 0; i < sizeOfBeans; i++) {
						//Added to have different Beans identified
						finalBeans[i] = (CrontabEntryBean)listOfBeans.get(i);
						finalBeans[i].setId(i);
					}
					cachedBeans = finalBeans;
				}
            }
			if (cachedBeans != null) {
				return cachedBeans;
			} else {
				throw  new DataNotFoundException("No CrontabEntries available");
			}
    	}
		
    /**
	 *	This method removes the CrontabEntryBean array from the File
	 *  @param CrontabEntryBean bean teh array of beans to remove
	 *  @throws Exception 
	 */
	 
    public synchronized void remove(CrontabEntryBean[] ceb) throws Exception {
	
        CrontabEntryBean[] thelist = findAll();
	    CrontabEntryBean[] result = new CrontabEntryBean[thelist.length - ceb.length];
	    
	    for (int i = 0; i < thelist.length ; i++) {
		    if (thelist[i] != null ) thelist[i].setId(-1);
		    for (int y = 0; y < ceb.length ; y++) {
		    	   ceb[y].setId(-1);
			    if (thelist[i] != null && thelist[i].equals(ceb[y])) {
				    thelist[i] = null;
			    } 
		    } 
	    }
	    
	    int resultCounter = 0;
	    for (int i = 0; i < thelist.length ; i++) {
		    if(thelist[i] != null) {
			result[resultCounter] = thelist[i];
			resultCounter++;
	        }
	    }
            storeAll(result);
	}
    
	/**
	 *	This method saves the CrontabEntryBean array the actual problem with this
	 *  method is that doesn�t store comments and blank lines from the original
	 *  file any ideas?
	 *  @param CrontabEntryBean bean this method stores the array of beans
	 *  @throws CrontabEntryException when it can't parse the line correctly
	 *  @throws IOException If it can't access correctly to the File
	 *  @throws DataNotFoundException whe it can't find nothing in the file usually 
	 *  Exception should'nt this 
	 */
    public synchronized void storeAll(CrontabEntryBean[] list) throws 
               CrontabEntryException, FileNotFoundException, IOException {

		    File fl = new File(Crontab.getInstance()
								.getProperty("org.jcrontab.data.file"));
		    PrintStream out = new PrintStream(new FileOutputStream(fl));
            for (int i = 0; i < list.length; i++){
			if (list[i] != null) {
		    			out.println("#");
                			out.println(cp.unmarshall(list[i]));
			}
            }
	    out.println("#");
	}
	/**
	 *  This method saves the CrontabEntryBean array the actual problem with this
	 *  method is that doesn�t store comments and blank lines from the original
	 *  file any ideas?
	 *  @param CrontabEntryBean bean this method stores the array of beans
	 *  @throws CrontabEntryException when it can't parse the line correctly
	 *  @throws IOException If it can't access correctly to the File
	 *  @throws DataNotFoundException whe it can't find nothing in the file usually 
	 *  Exception should'nt this 
	 */
	public synchronized void store(CrontabEntryBean[] beans) throws CrontabEntryException, 
			IOException, DataNotFoundException {
            CrontabEntryBean[]  thelist = null;
	    boolean succedded = false;
	    try {
            thelist = findAll();
	    succedded = true;
	    } catch (Exception e) {
		    if (e instanceof DataNotFoundException) {
			    storeAll(beans);
		    } else {
		    throw new 
		    	DataNotFoundException("Unable to find CrontabEntries");
		    }
	    }
	    if (succedded) {
		    int size = (thelist.length +1 );
		    
		    CrontabEntryBean[] resultlist = new CrontabEntryBean[size];
		    Vector ve = new Vector();
		    for (int i = 0; i < thelist.length; i++){
			ve.add(thelist[i]);
		    }
				for (int i = 0; i < beans.length; i++) {
					ve.add(beans[i]);
				}
		    for (int i = 0; i < ve.size(); i++){
			resultlist[i] = (CrontabEntryBean)ve.get(i);
		    }
		    storeAll(resultlist);
	    }
	}
	
	/**
	 *	This method saves the CrontabEntryBean the actual problem with this
	 *  method is that doesn�t store comments and blank lines from the original
	 *  file any ideas?
	 *  @param CrontabEntryBean bean this method only lets store an entryBean
	 *  each time.
	 *  @throws CrontabEntryException when it can't parse the line correctly
	 *  @throws IOException If it can't access correctly to the File
	 *  @throws DataNotFoundException whe it can't find nothing in the file usually 
	 *  Exception should'nt this 
	 */
	public synchronized void store(CrontabEntryBean bean) throws CrontabEntryException, 
			IOException, DataNotFoundException {
            CrontabEntryBean[] thelist = null;
	    boolean succedded = false;
            try {
            thelist = findAll();
	    succedded = true;
	    } catch (Exception e) {
		    if (e instanceof DataNotFoundException) {
			    CrontabEntryBean[] ilist = new CrontabEntryBean[1];
			    ilist[0] = bean;
			    storeAll(ilist);
		    } else {
		    throw new 
		    	DataNotFoundException("Unable to find CrontabEntries");
		    }
	    }
	    if (succedded) {
		    int size = (thelist.length +1 );
		    
		    CrontabEntryBean[] resultlist = new CrontabEntryBean[size];
		    Vector ve = new Vector();
		    for (int i = 0; i < thelist.length; i++){
			ve.add(thelist[i]);
		    }
		    ve.add(bean);
		    for (int i = 0; i < ve.size(); i++){
			resultlist[i] = (CrontabEntryBean)ve.get(i);
		    }
		    storeAll(resultlist);
	    }
	}
}