/*
* Copyright (C) The Apache Software Foundation. All rights reserved.
*
* This software is published under the terms of the Apache Software License
* version 1.1, a copy of which has been included with this distribution in
* the LICENSE file.
*/
package org.apache.james.mailrepository;
import org.apache.avalon.cornerstone.services.store.ObjectRepository;
import org.apache.avalon.cornerstone.services.store.Store;
import org.apache.avalon.cornerstone.services.store.StreamRepository;
import org.apache.avalon.framework.activity.Initializable;
import org.apache.avalon.framework.component.Component;
import org.apache.avalon.framework.component.ComponentException;
import org.apache.avalon.framework.component.ComponentManager;
import org.apache.avalon.framework.component.Composable;
import org.apache.avalon.framework.configuration.Configurable;
import org.apache.avalon.framework.configuration.Configuration;
import org.apache.avalon.framework.configuration.ConfigurationException;
import org.apache.avalon.framework.configuration.DefaultConfiguration;
import org.apache.avalon.framework.logger.AbstractLogEnabled;
import org.apache.james.core.MailImpl;
import org.apache.james.core.MimeMessageWrapper;
import org.apache.james.services.MailRepository;
import org.apache.james.services.MailStore;
import org.apache.james.util.Lock;
import java.io.OutputStream;
import java.util.*;
/**
* Implementation of a MailRepository on a FileSystem.
*
* Requires a configuration element in the .conf.xml file of the form:
* <repository destinationURL="file://path-to-root-dir-for-repository"
* type="MAIL"
* model="SYNCHRONOUS"/>
* Requires a logger called MailRepository.
*
* @version 1.0.0, 24/04/1999
* @author Federico Barbieri <scoobie@pop.systemy.it>
* @author Charles Benett <charles@benett1.demon.co.uk>
*/
public class AvalonMailRepository
extends AbstractLogEnabled
implements MailRepository, Component, Configurable, Composable, Initializable {
/**
* Whether 'deep debugging' is turned on.
*/
protected final static boolean DEEP_DEBUG = false;
private static final String TYPE = "MAIL";
private Lock lock;
private Store store;
private StreamRepository sr;
private ObjectRepository or;
private MailStore mailstore;
private String destination;
private Set keys;
/**
* @see org.apache.avalon.framework.component.Composable#compose(ComponentManager)
*/
public void compose( final ComponentManager componentManager )
throws ComponentException {
store = (Store)componentManager.
lookup( "org.apache.avalon.cornerstone.services.store.Store" );
}
/**
* @see org.apache.avalon.framework.configuration.Configurable#configure(Configuration)
*/
public void configure(Configuration conf) throws ConfigurationException {
destination = conf.getAttribute("destinationURL");
if (getLogger().isDebugEnabled()) {
getLogger().debug("AvalonMailRepository.destinationURL: " + destination);
}
String checkType = conf.getAttribute("type");
if (! (checkType.equals("MAIL") || checkType.equals("SPOOL")) ) {
String exceptionString = "Attempt to configure AvalonMailRepository as " +
checkType;
if (getLogger().isWarnEnabled()) {
getLogger().warn(exceptionString);
}
throw new ConfigurationException(exceptionString);
}
// ignore model
}
/**
* @see org.apache.avalon.framework.activity.Initializable#initialize()
*/
public void initialize()
throws Exception {
try {
//prepare Configurations for object and stream repositories
DefaultConfiguration objectConfiguration
= new DefaultConfiguration( "repository",
"generated:AvalonFileRepository.compose()" );
objectConfiguration.setAttribute("destinationURL", destination);
objectConfiguration.setAttribute("type", "OBJECT");
objectConfiguration.setAttribute("model", "SYNCHRONOUS");
DefaultConfiguration streamConfiguration
= new DefaultConfiguration( "repository",
"generated:AvalonFileRepository.compose()" );
streamConfiguration.setAttribute( "destinationURL", destination );
streamConfiguration.setAttribute( "type", "STREAM" );
streamConfiguration.setAttribute( "model", "SYNCHRONOUS" );
sr = (StreamRepository) store.select(streamConfiguration);
or = (ObjectRepository) store.select(objectConfiguration);
lock = new Lock();
keys = Collections.synchronizedSet(new HashSet());
//Finds non-matching pairs and deletes the extra files
HashSet streamKeys = new HashSet();
for (Iterator i = sr.list(); i.hasNext(); ) {
streamKeys.add(i.next());
}
HashSet objectKeys = new HashSet();
for (Iterator i = or.list(); i.hasNext(); ) {
objectKeys.add(i.next());
}
Collection strandedStreams = (Collection)streamKeys.clone();
strandedStreams.removeAll(objectKeys);
for (Iterator i = strandedStreams.iterator(); i.hasNext(); ) {
String key = (String)i.next();
remove(key);
}
Collection strandedObjects = (Collection)objectKeys.clone();
strandedObjects.removeAll(streamKeys);
for (Iterator i = strandedObjects.iterator(); i.hasNext(); ) {
String key = (String)i.next();
remove(key);
}
//Next get a list from the object repository
// and use that for the list of keys
keys.clear();
for (Iterator i = or.list(); i.hasNext(); ) {
keys.add(i.next());
}
if (getLogger().isDebugEnabled()) {
StringBuffer logBuffer =
new StringBuffer(128)
.append(this.getClass().getName())
.append(" created in ")
.append(destination);
getLogger().debug(logBuffer.toString());
}
} catch (Exception e) {
final String message = "Failed to retrieve Store component:" + e.getMessage();
getLogger().error( message, e );
throw e;
}
}
/**
* Releases a lock on a message identified by a key
*
* @param key the key of the message to be unlocked
*
* @return true if successfully released the lock, false otherwise
*/
public boolean unlock(String key) {
if (lock.unlock(key)) {
if ((DEEP_DEBUG) && (getLogger().isDebugEnabled())) {
StringBuffer debugBuffer =
new StringBuffer(256)
.append("Unlocked ")
.append(key)
.append(" for ")
.append(Thread.currentThread().getName())
.append(" @ ")
.append(new java.util.Date(System.currentTimeMillis()));
getLogger().debug(debugBuffer.toString());
}
synchronized (this) {
notifyAll();
}
return true;
} else {
return false;
}
}
/**
* Obtains a lock on a message identified by a key
*
* @param key the key of the message to be locked
*
* @return true if successfully obtained the lock, false otherwise
*/
public boolean lock(String key) {
if (lock.lock(key)) {
if ((DEEP_DEBUG) && (getLogger().isDebugEnabled())) {
StringBuffer debugBuffer =
new StringBuffer(256)
.append("Locked ")
.append(key)
.append(" for ")
.append(Thread.currentThread().getName())
.append(" @ ")
.append(new java.util.Date(System.currentTimeMillis()));
getLogger().debug(debugBuffer.toString());
}
synchronized (this) {
notifyAll();
}
return true;
} else {
return false;
}
}
/**
* Stores a message in this repository. Shouldn't this return the key
* under which it is stored?
*
* @param mc the mail message to store
*/
public void store(MailImpl mc) {
try {
String key = mc.getName();
//Remember whether this key was locked
boolean wasLocked = lock.isLocked(key);
if (!wasLocked) {
//If it wasn't locked, we want a lock during the store
lock.lock(key);
}
try {
if (!keys.contains(key)) {
keys.add(key);
}
boolean saveStream = true;
if (mc.getMessage() instanceof MimeMessageWrapper) {
MimeMessageWrapper wrapper = (MimeMessageWrapper) mc.getMessage();
if (DEEP_DEBUG) {
System.out.println("Retrieving from: " + wrapper.getSourceId());
StringBuffer debugBuffer =
new StringBuffer(64)
.append("Saving to: ")
.append(destination)
.append("/")
.append(mc.getName());
System.out.println(debugBuffer.toString());
System.out.println("Modified: " + wrapper.isModified());
}
StringBuffer destinationBuffer =
new StringBuffer(128)
.append(destination)
.append("/")
.append(mc.getName());
if (wrapper.getSourceId().equals(destinationBuffer.toString()) && !wrapper.isModified()) {
//We're trying to save to the same place, and it's not modified... we shouldn't save.
//More importantly, if we try to save, we will create a 0-byte file since we're
//retrying to retrieve from a file we'll be overwriting.
saveStream = false;
}
}
if (saveStream) {
OutputStream out = null;
try {
out = sr.put(key);
mc.writeMessageTo(out);
} finally {
out.close();
}
}
//Always save the header information
or.put(key, mc);
} finally {
if (!wasLocked) {
//If it wasn't locked, we need to now unlock
lock.unlock(key);
}
}
if ((DEEP_DEBUG) && (getLogger().isDebugEnabled())) {
StringBuffer logBuffer =
new StringBuffer(64)
.append("Mail ")
.append(key)
.append(" stored.");
getLogger().debug(logBuffer.toString());
}
synchronized (this) {
notifyAll();
}
} catch (Exception e) {
getLogger().error("Exception storing mail: " + e);
e.printStackTrace();
throw new RuntimeException("Exception caught while storing Message Container: " + e);
}
}
/**
* Retrieves a message given a key. At the moment, keys can be obtained
* from list() in superinterface Store.Repository
*
* @param key the key of the message to retrieve
* @return the mail corresponding to this key, null if none exists
*/
public MailImpl retrieve(String key) {
if ((DEEP_DEBUG) && (getLogger().isDebugEnabled())) {
getLogger().debug("Retrieving mail: " + key);
}
try {
MailImpl mc = null;
try {
mc = (MailImpl) or.get(key);
} catch (RuntimeException re) {
StringBuffer exceptionBuffer =
new StringBuffer(128)
.append("Exception retrieving mail: ")
.append(re.toString())
.append(", so we're deleting it... good riddance!");
getLogger().error(exceptionBuffer.toString());
remove(key);
return null;
}
MimeMessageAvalonSource source = new MimeMessageAvalonSource(sr, destination, key);
mc.setMessage(new MimeMessageWrapper(source));
return mc;
} catch (Exception me) {
getLogger().error("Exception retrieving mail: " + me);
throw new RuntimeException("Exception while retrieving mail: " + me.getMessage());
}
}
/**
* Removes a specified message
*
* @param mail the message to be removed from the repository
*/
public void remove(MailImpl mail) {
remove(mail.getName());
}
/**
* Removes a message identified by key.
*
* @param key the key of the message to be removed from the repository
*/
public void remove(String key) {
if (lock(key)) {
try {
keys.remove(key);
sr.remove(key);
or.remove(key);
} finally {
unlock(key);
}
} else {
StringBuffer exceptionBuffer =
new StringBuffer(64)
.append("Cannot lock ")
.append(key)
.append(" to remove it");
throw new RuntimeException(exceptionBuffer.toString());
}
}
/**
* List string keys of messages in repository.
*
* @return an <code>Iterator</code> over the list of keys in the repository
*
*/
public Iterator list() {
// Fix ConcurrentModificationException by cloning
// the keyset before getting an iterator
final HashSet clone = new HashSet();
clone.addAll( keys );
return clone.iterator();
}
}