fileopener.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.InputStream;
import java.io.FileInputStream;
import java.io.File;
import java.io.IOException;
import java.util.Properties;
/**
 *	This class get an InputStream using the right method, File or 
 * getResourceAsStream, The idea of this way of openning files is from 
 * Sergey Udalstov
 * @author $Author: iolalla $
 * @version $Revision: 1.4 $
 */

public class FileOpener {
    
    private static String type;
    
    static {
        type = org.jcrontab.Crontab.getInstance().getProperty("org.jcrontab.data.FileOpener");
    }
    /**
     * This method is the reason of this class and basically loads the 
     *  File with the given method.
     * @return InputStream The inputStream to work with
     * @param Class cl The class to load from only used if getResourceAsStream
     * is used
     * @param name String the name of the file to load
     * @param type how to load the file.
     * @throws Exception the thrown exceptions 
     */
    
    public InputStream getInputStream(Class cl, 
                                String name) throws Exception {
        InputStream is = null;
        if ("class".compareToIgnoreCase(type) == 0) {
            is = cl.getClassLoader().getResourceAsStream(name);
            if (is == null) 
                throw new IOException(name + " not Found.");
        } else if ("file".compareToIgnoreCase(type) == 0) {
            File file = new File (name);
            is = new FileInputStream(file);
        } else {
            throw new UnsupportedOperationException("should call with class or file"
                                                    + " no with : " + type );
        }
        return is;
    }
}