001/**************************************************************** 002 * Licensed to the Apache Software Foundation (ASF) under one * 003 * or more contributor license agreements. See the NOTICE file * 004 * distributed with this work for additional information * 005 * regarding copyright ownership. The ASF licenses this file * 006 * to you under the Apache License, Version 2.0 (the * 007 * "License"); you may not use this file except in compliance * 008 * with the License. You may obtain a copy of the License at * 009 * * 010 * http://www.apache.org/licenses/LICENSE-2.0 * 011 * * 012 * Unless required by applicable law or agreed to in writing, * 013 * software distributed under the License is distributed on an * 014 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY * 015 * KIND, either express or implied. See the License for the * 016 * specific language governing permissions and limitations * 017 * under the License. * 018 ****************************************************************/ 019 020package org.apache.james.mime4j.storage; 021 022import java.io.ByteArrayInputStream; 023import java.io.IOException; 024import java.io.InputStream; 025 026import org.apache.james.mime4j.util.ByteArrayBuffer; 027 028/** 029 * A {@link StorageProvider} that stores the data entirely in memory. 030 * <p> 031 * Example usage: 032 * 033 * <pre> 034 * StorageProvider provider = new MemoryStorageProvider(); 035 * DefaultStorageProvider.setInstance(provider); 036 * </pre> 037 */ 038public class MemoryStorageProvider extends AbstractStorageProvider { 039 040 /** 041 * Creates a new <code>MemoryStorageProvider</code>. 042 */ 043 public MemoryStorageProvider() { 044 } 045 046 public StorageOutputStream createStorageOutputStream() { 047 return new MemoryStorageOutputStream(); 048 } 049 050 private static final class MemoryStorageOutputStream extends 051 StorageOutputStream { 052 ByteArrayBuffer bab = new ByteArrayBuffer(1024); 053 054 @Override 055 protected void write0(byte[] buffer, int offset, int length) 056 throws IOException { 057 bab.append(buffer, offset, length); 058 } 059 060 @Override 061 protected Storage toStorage0() throws IOException { 062 return new MemoryStorage(bab.buffer(), bab.length()); 063 } 064 } 065 066 static final class MemoryStorage implements Storage { 067 private byte[] data; 068 private final int count; 069 070 public MemoryStorage(byte[] data, int count) { 071 this.data = data; 072 this.count = count; 073 } 074 075 public InputStream getInputStream() throws IOException { 076 if (data == null) 077 throw new IllegalStateException("storage has been deleted"); 078 079 return new ByteArrayInputStream(data, 0, count); 080 } 081 082 public void delete() { 083 data = null; 084 } 085 } 086 087}