| /* |
| * 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.geronimo.javamail.util; |
| |
| import java.io.IOException; |
| import java.io.Reader; |
| |
| /** |
| * An implementation of an OutputStream that performs MIME linebreak |
| * canonicalization and "byte-stuff" so that data content does not get mistaken |
| * for a message data-end marker (CRLF.CRLF)l |
| * |
| * @version $Rev$ $Date$ |
| */ |
| public class MIMEInputReader extends Reader { |
| |
| // the wrappered output stream. |
| protected Reader source; |
| |
| // a flag to indicate we've just processed a line break. This is used for |
| // byte stuffing purposes. This |
| // is initially true, because if the first character of the content is a |
| // period, we need to byte-stuff |
| // immediately. |
| protected boolean atLineBreak = true; |
| // we've hit the terminating marker on the data |
| protected boolean endOfData = false; |
| |
| |
| /** |
| * Create an input reader that reads from the source input reader |
| * |
| * @param out |
| * The wrapped Reader |
| */ |
| public MIMEInputReader(Reader source) { |
| this.source = source; |
| } |
| |
| /** |
| * Concrete implementation of the Reader read() |
| * abstract method. This appears to be the only |
| * abstract method, so all of the other reads must |
| * funnel through this method. |
| * |
| * @param buffer The buffer to fill. |
| * @param off The offset to start adding characters. |
| * @param len The number of requested characters. |
| * |
| * @return The actual count of characters read. Returns -1 |
| * if we hit an EOF without reading any characters. |
| * @exception IOException |
| */ |
| public int read(char buffer[], int off, int len) throws IOException { |
| // we've been asked for nothing, we'll return nothing. |
| if (len == 0) { |
| return 0; |
| } |
| |
| // have we hit the end of data? Return a -1 indicator |
| if (endOfData) { |
| return -1; |
| } |
| |
| // number of bytes read |
| int bytesRead = 0; |
| |
| int lastRead; |
| |
| while (bytesRead < len && (lastRead = source.read()) >= 0) { |
| // We are checking for the end of a multiline response |
| // the format is .CRLF |
| |
| // we also have to check for byte-stuffing situation |
| // where we remove a leading period. |
| if (atLineBreak && lastRead == '.') { |
| // step to the next character |
| lastRead = source.read(); |
| // we have ".CR"...this is our end of stream |
| // marker. Consume the LF from the reader and return |
| if (lastRead == '\r') { |
| source.read(); |
| // no more reads from this point. |
| endOfData = true; |
| break; |
| } |
| // the next character SHOULD be a ".". We swallow the first |
| // dot and just write the next character to the buffer |
| atLineBreak = false; |
| } |
| else if (lastRead == '\n') { |
| // hit an end-of-line marker? |
| // remember we just had a line break |
| atLineBreak = true; |
| } |
| else |
| { |
| // something other than a line break character |
| atLineBreak = false; |
| } |
| // add the character to the buffer |
| buffer[off++] = (char)lastRead; |
| bytesRead++; |
| } |
| |
| // we must have had an EOF condition of some sort |
| if (bytesRead == 0) { |
| return -1; |
| } |
| // return the actual length read in |
| return bytesRead; |
| } |
| |
| /** |
| * Close the stream. This is a NOP for this stream. |
| * |
| * @exception IOException |
| */ |
| public void close() throws IOException { |
| // does nothing |
| } |
| } |
| |