| /**************************************************************** |
| * 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.mime4j.io; |
| |
| import java.io.IOException; |
| import java.io.InputStream; |
| import java.io.PushbackInputStream; |
| |
| /** |
| * InputStream which converts <code>\r</code> |
| * bytes not followed by <code>\n</code> and <code>\n</code> not |
| * preceded by <code>\r</code> to <code>\r\n</code>. |
| */ |
| public class EOLConvertingInputStream extends InputStream { |
| /** Converts single '\r' to '\r\n' */ |
| public static final int CONVERT_CR = 1; |
| /** Converts single '\n' to '\r\n' */ |
| public static final int CONVERT_LF = 2; |
| /** Converts single '\r' and '\n' to '\r\n' */ |
| public static final int CONVERT_BOTH = 3; |
| |
| private PushbackInputStream in = null; |
| private int previous = 0; |
| private int flags = CONVERT_BOTH; |
| |
| /** |
| * Creates a new <code>EOLConvertingInputStream</code> |
| * instance converting bytes in the given <code>InputStream</code>. |
| * The flag <code>CONVERT_BOTH</code> is the default. |
| * |
| * @param in the <code>InputStream</code> to read from. |
| */ |
| public EOLConvertingInputStream(InputStream in) { |
| this(in, CONVERT_BOTH); |
| } |
| /** |
| * Creates a new <code>EOLConvertingInputStream</code> |
| * instance converting bytes in the given <code>InputStream</code>. |
| * |
| * @param in the <code>InputStream</code> to read from. |
| * @param flags one of <code>CONVERT_CR</code>, <code>CONVERT_LF</code> or |
| * <code>CONVERT_BOTH</code>. |
| */ |
| public EOLConvertingInputStream(InputStream in, int flags) { |
| super(); |
| |
| this.in = new PushbackInputStream(in, 2); |
| this.flags = flags; |
| } |
| |
| /** |
| * Closes the underlying stream. |
| * |
| * @throws IOException on I/O errors. |
| */ |
| @Override |
| public void close() throws IOException { |
| in.close(); |
| } |
| |
| /** |
| * @see java.io.InputStream#read() |
| */ |
| @Override |
| public int read() throws IOException { |
| int b = in.read(); |
| |
| if (b == -1) { |
| return -1; |
| } |
| |
| if ((flags & CONVERT_CR) != 0 && b == '\r') { |
| int c = in.read(); |
| if (c != -1) { |
| in.unread(c); |
| } |
| if (c != '\n') { |
| in.unread('\n'); |
| } |
| } else if ((flags & CONVERT_LF) != 0 && b == '\n' && previous != '\r') { |
| b = '\r'; |
| in.unread('\n'); |
| } |
| |
| previous = b; |
| |
| return b; |
| } |
| |
| } |