org.apache.james.mailrepository.lib.AbstractMailRepository.java Source code

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Here is the source code for org.apache.james.mailrepository.lib.AbstractMailRepository.java

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/****************************************************************
 * 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                 *
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 * 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.                                           *
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package org.apache.james.mailrepository.lib;

import java.io.IOException;
import java.util.Collection;

import javax.mail.MessagingException;

import org.apache.commons.configuration.ConfigurationException;
import org.apache.commons.configuration.HierarchicalConfiguration;
import org.apache.james.lifecycle.api.Configurable;
import org.apache.james.lifecycle.api.LogEnabled;
import org.apache.james.mailrepository.api.MailRepository;
import org.apache.james.repository.api.Initializable;
import org.apache.mailet.Mail;
import org.slf4j.Logger;

/**
 * This class represent an AbstractMailRepository. All MailRepositories should
 * extend this class.
 */
public abstract class AbstractMailRepository implements MailRepository, LogEnabled, Configurable, Initializable {

    /**
     * Whether 'deep debugging' is turned on.
     */
    protected static final boolean DEEP_DEBUG = false;

    /**
     * A lock used to control access to repository elements, locking access
     * based on the key
     */
    private final Lock lock = new Lock();

    private Logger logger;

    public void setLog(Logger logger) {
        this.logger = logger;
    }

    protected Logger getLogger() {
        return logger;
    }

    public void configure(HierarchicalConfiguration configuration) throws ConfigurationException {
        doConfigure(configuration);
    }

    protected void doConfigure(HierarchicalConfiguration config) throws ConfigurationException {

    }

    /**
     * @see org.apache.james.mailrepository.api.MailRepository#unlock(String)
     */
    public boolean unlock(String key) {
        return lock.unlock(key);
    }

    /**
     * @see org.apache.james.mailrepository.api.MailRepository#lock(String)
     */
    public boolean lock(String key) {
        return lock.lock(key);
    }

    /**
     * @see org.apache.james.mailrepository.api.MailRepository#store(Mail)
     */
    public void store(Mail mc) throws MessagingException {
        boolean wasLocked = true;
        String key = mc.getName();
        try {
            synchronized (this) {
                wasLocked = lock.isLocked(key);
                if (!wasLocked) {
                    // If it wasn't locked, we want a lock during the store
                    lock(key);
                }
            }
            internalStore(mc);
        } catch (MessagingException e) {
            getLogger().error("Exception caught while storing mail " + key, e);
            throw e;
        } catch (Exception e) {
            getLogger().error("Exception caught while storing mail " + key, e);
            throw new MessagingException("Exception caught while storing mail " + key, e);
        } finally {
            if (!wasLocked) {
                // If it wasn't locked, we need to unlock now
                unlock(key);
                synchronized (this) {
                    notify();
                }
            }
        }
    }

    /**
     * @see #store(Mail)
     */
    protected abstract void internalStore(Mail mc) throws MessagingException, IOException;

    /**
     * @see org.apache.james.mailrepository.api.MailRepository#remove(Mail)
     */
    public void remove(Mail mail) throws MessagingException {
        remove(mail.getName());
    }

    /**
     * @see org.apache.james.mailrepository.api.MailRepository#remove(Collection)
     */
    public void remove(Collection<Mail> mails) throws MessagingException {
        for (Mail mail : mails) {
            remove(mail);
        }
    }

    /**
     * @see org.apache.james.mailrepository.api.MailRepository#remove(String)
     */
    public void remove(String key) throws MessagingException {
        if (lock(key)) {
            try {
                internalRemove(key);
            } finally {
                unlock(key);
            }
        } else {
            String exceptionBuffer = "Cannot lock " + key + " to remove it";
            throw new MessagingException(exceptionBuffer.toString());
        }
    }

    /**
     * @see #remove(String)
     */
    protected abstract void internalRemove(String key) throws MessagingException;

}