/* ==================================================================== * The Apache Software License, Version 1.1 * * Copyright (c) 2000-2003 The Apache Software Foundation. All rights * reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in * the documentation and/or other materials provided with the * distribution. * * 3. The end-user documentation included with the redistribution, * if any, must include the following acknowledgment: * "This product includes software developed by the * Apache Software Foundation (http://www.apache.org/)." * Alternately, this acknowledgment may appear in the software itself, * if and wherever such third-party acknowledgments normally appear. * * 4. The names "Apache", "Jakarta", "JAMES" and "Apache Software Foundation" * must not be used to endorse or promote products derived from this * software without prior written permission. For written * permission, please contact apache@apache.org. * * 5. Products derived from this software may not be called "Apache", * nor may "Apache" appear in their name, without prior written * permission of the Apache Software Foundation. * * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE * DISCLAIMED. IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. * ==================================================================== * * This software consists of voluntary contributions made by many * individuals on behalf of the Apache Software Foundation. For more * information on the Apache Software Foundation, please see * . * * Portions of this software are based upon public domain software * originally written at the National Center for Supercomputing Applications, * University of Illinois, Urbana-Champaign. */ package org.apache.james.util; import java.io.InputStream; import java.io.BufferedReader; import java.io.UnsupportedEncodingException; import java.io.IOException; import java.io.InputStreamReader; /** * A Reader for use with SMTP or other protocols in which lines * must end with CRLF. Extends BufferedReader and overrides its * readLine() method. The BufferedReader readLine() method cannot * serve for SMTP because it ends lines with either CR or LF alone. */ public class CRLFTerminatedReader extends BufferedReader { public class TerminationError extends IOException { private int where; public TerminationError(int where) { super(); this.where = where; } public TerminationError(String s, int where) { super(s); this.where = where; } public int position() { return where; } } /** * Constructs this CRLFTerminatedReader. * @param in an InputStream * @param charsetName the String name of a supported charset. * "ASCII" is common here. * @throws UnsupportedEncodingException if the named charset * is not supported */ public CRLFTerminatedReader(InputStream in, String charsetName) throws UnsupportedEncodingException { super(new InputStreamReader(in, charsetName)); } private StringBuffer lineBuffer = new StringBuffer(); private final int EOF = -1, CR = 13, LF = 10; private int tainted = -1; /** * Read a line of text which is terminated by CRLF. The concluding * CRLF characters are not returned with the String, but if either CR * or LF appears in the text in any other sequence it is returned * in the String like any other character. Some characters at the * end of the stream may be lost if they are in a "line" not * terminated by CRLF. * * @return either a String containing the contents of a * line which must end with CRLF, or null if the end of the * stream has been reached, possibly discarding some characters * in a line not terminated with CRLF. * @throws IOException if an I/O error occurs. */ public String readLine() throws IOException{ //start with the StringBuffer empty lineBuffer.delete(0, lineBuffer.length()); /* This boolean tells which state we are in, * depending upon whether or not we got a CR * in the preceding read(). */ boolean cr_just_received = false; while (true){ int inChar = read(); if (!cr_just_received){ //the most common case, somewhere before the end of a line switch (inChar){ case CR : cr_just_received = true; break; case EOF : return null; // premature EOF -- discards data(?) case LF : //the normal ending of a line if (tainted == -1) tainted = lineBuffer.length(); // intentional fall-through default : lineBuffer.append((char)inChar); } }else{ // CR has been received, we may be at end of line switch (inChar){ case LF : //the normal ending of a line if (tainted != -1) { int pos = tainted; tainted = -1; throw new TerminationError("\"bare\" CR or LF in data stream", pos); } return lineBuffer.toString(); case EOF : return null; // premature EOF -- discards data(?) case CR : //we got two (or more) CRs in a row if (tainted == -1) tainted = lineBuffer.length(); lineBuffer.append((char)CR); break; default : //we got some other character following a CR if (tainted == -1) tainted = lineBuffer.length(); lineBuffer.append((char)CR); lineBuffer.append((char)inChar); cr_just_received = false; } } }//while }//method readLine() }