com.liusoft.dlog4j.MailTransportQueue.java Source code

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Here is the source code for com.liusoft.dlog4j.MailTransportQueue.java

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/*
 *  MailTransportQueue.java
 *  
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation; either version 2 of the License, or
 *  (at your option) any later version.
 *
 *  This program 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 Library General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program; if not, write to the Free Software
 *  Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
 *  
 *  Author: Winter Lau (javayou@gmail.com)
 *  http://dlog4j.sourceforge.net
 */
package com.liusoft.dlog4j;

import java.io.File;
import java.io.FileFilter;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.FilenameFilter;
import java.io.IOException;
import java.util.List;

import javax.mail.MessagingException;
import javax.mail.Session;
import javax.mail.internet.MimeMessage;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;

/**
 * 
 * ????
 * TODO: : ??,?
 * @author Winter Lau
 */
public class MailTransportQueue {
    private final static Log log = LogFactory.getLog(MailTransportQueue.class);

    private final static String EML = ".eml";
    private final static String ERR = ".err";

    private static MailTransportQueue queue;

    /**
     * ?
     * @param path
     * @return
     */
    public synchronized final static MailTransportQueue getInstance(String path) {
        if (queue == null) {
            queue = new MailTransportQueue(path);
        }
        return queue;
    }

    private String path; //

    protected MailTransportQueue(String path) {
        this.path = path;
        if (this.path.endsWith(File.separator))
            this.path += File.separator;
        File f = new File(this.path);
        if (!f.exists())
            f.mkdirs();
    }

    /**
     * ?
     * @param sid
     * @param mail
     * @return ??()
     * @throws IOException 
     * @throws MessagingException 
     */
    public String write(int sid, MimeMessage mail) throws IOException, MessagingException {
        int tryCount = 0;
        do {
            StringBuffer fn = new StringBuffer(path);
            fn.append(System.currentTimeMillis());
            fn.append('_');
            fn.append(sid);
            fn.append(EML);
            File f = new File(fn.toString());
            if (f.exists()) {
                tryCount++;
                try {
                    Thread.sleep(10);
                } catch (InterruptedException e) {
                    break;
                }
            } else if (f.createNewFile()) {
                FileOutputStream fos = new FileOutputStream(f);
                try {
                    mail.writeTo(fos);
                    return f.getPath();
                } finally {
                    fos.close();
                }
            }
            break;
        } while (tryCount < 10);

        return null;
    }

    /**
     * ??
     * @param mails ?,?
     * @param ident ?,
     * @param max_count 
     * @return 
     * @throws IOException 
     */
    public int read(Session ssn, List mails, List ident, int max_count) throws IOException {
        File fs = new File(path);
        File[] mailfiles = fs.listFiles(new FileFilter() {
            public boolean accept(File f) {
                if (f.length() > 0 && f.getName().endsWith(EML))
                    return true;
                return false;
            }
        });
        if (mails != null) {
            for (int i = 0; i < mailfiles.length && i < max_count; i++) {
                FileInputStream fis = null;
                try {
                    fis = new FileInputStream(mailfiles[i]);
                    mails.add(new MimeMessage(ssn, fis));
                    if (ident != null)
                        ident.add(mailfiles[i].getPath());
                    fis.close();
                    fis = null;
                    mailfiles[i].delete();
                } catch (MessagingException e) {
                    String newfile = mailfiles[i].getPath() + ERR;
                    mailfiles[i].renameTo(new File(newfile));
                    log.error("mail cache file destroy, rename to " + newfile, e);
                } catch (IOException e) {
                    String newfile = mailfiles[i].getPath() + ERR;
                    mailfiles[i].renameTo(new File(newfile));
                    log.error("IO Exception when read mail cache , rename to " + newfile, e);
                } finally {
                    if (fis != null)
                        fis.close();
                }
            }
        }
        return mailfiles.length;
    }

    /**
     * ?
     * @return
     */
    public int queueSize() {
        File fs = new File(path);
        try {
            return fs.list(fnFilter).length;
        } finally {
            fs = null;
        }
    }

    /**
     * 
     * @see com.liusoft.dlog4j.MailTransportQueue#queueSize()
     */
    private static FilenameFilter fnFilter = new FilenameFilter() {
        public boolean accept(File path, String fn) {
            return fn.endsWith(EML);
        }
    };

    /**
     * @param args
     */
    public static void main(String[] args) {

    }

}