Java tutorial
/**************************************************************** * 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 * * * * 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. * ****************************************************************/ package org.apache.james.mailbox.jpa.mail.model.openjpa; import java.io.IOException; import java.io.InputStream; import java.util.Date; import javax.mail.Flags; import javax.mail.internet.SharedInputStream; import javax.mail.util.SharedByteArrayInputStream; import javax.persistence.Column; import javax.persistence.Entity; import javax.persistence.FetchType; import javax.persistence.Table; import org.apache.commons.io.IOUtils; import org.apache.james.mailbox.exception.MailboxException; import org.apache.james.mailbox.jpa.mail.model.JPAMailbox; import org.apache.james.mailbox.store.mail.model.MailboxMessage; import org.apache.james.mailbox.store.mail.model.impl.PropertyBuilder; import org.apache.openjpa.persistence.Persistent; /** * JPA implementation of {@link AbstractJPAMailboxMessage} which use openjpas {@link Persistent} type to * be able to stream the message content without loading it into the memory at all. * * This is not supported for all DB's yet. See <a href="http://openjpa.apache.org/builds/latest/docs/manual/ref_guide_mapping_jpa.html">Additional JPA Mappings</a> * * If your DB is not supported by this, use {@link JPAMailboxMessage} * * TODO: Fix me! */ @Entity(name = "MailboxMessage") @Table(name = "JAMES_MAIL") public class JPAStreamingMailboxMessage extends AbstractJPAMailboxMessage { @Persistent(optional = false, fetch = FetchType.LAZY) @Column(name = "MAIL_BYTES", length = 1048576000, nullable = false) private InputStream body; @Persistent(optional = false, fetch = FetchType.LAZY) @Column(name = "HEADER_BYTES", length = 10485760, nullable = false) private InputStream header; private final SharedInputStream content; public JPAStreamingMailboxMessage(JPAMailbox mailbox, Date internalDate, int size, Flags flags, SharedInputStream content, int bodyStartOctet, PropertyBuilder propertyBuilder) throws MailboxException { super(mailbox, internalDate, flags, size, bodyStartOctet, propertyBuilder); this.content = content; try { this.header = getHeaderContent(); this.body = getBodyContent(); } catch (IOException e) { throw new MailboxException("Unable to parse message", e); } } /** * Create a copy of the given message */ public JPAStreamingMailboxMessage(JPAMailbox mailbox, long uid, long modSeq, MailboxMessage message) throws MailboxException { super(mailbox, uid, modSeq, message); try { this.content = new SharedByteArrayInputStream(IOUtils.toByteArray(message.getFullContent())); this.header = getHeaderContent(); this.body = getBodyContent(); } catch (IOException e) { throw new MailboxException("Unable to parse message", e); } } @Override public InputStream getBodyContent() throws IOException { return content.newStream(getBodyStartOctet(), -1); } @Override public InputStream getHeaderContent() throws IOException { int headerEnd = getBodyStartOctet() - 2; if (headerEnd < 0) { headerEnd = 0; } return content.newStream(0, headerEnd); } }