/*
* $Header: /home/jerenkrantz/tmp/commons/commons-convert/cvs/home/cvs/jakarta-commons//httpclient/src/java/org/apache/commons/httpclient/HttpParser.java,v 1.13 2005/01/11 13:57:06 oglueck Exp $
* $Revision: 533405 $
* $Date: 2007-04-28 20:19:29 +0200 (Sat, 28 Apr 2007) $
*
* ====================================================================
*
* 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.
* ====================================================================
*
* 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
* <http://www.apache.org/>.
*
*/
package org.apache.commons.httpclient;
import java.io.IOException;
import java.io.InputStream;
import java.io.ByteArrayOutputStream;
import java.util.ArrayList;
import org.apache.commons.httpclient.util.EncodingUtil;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
/**
* A utility class for parsing http header values according to
* RFC-2616 Section 4 and 19.3.
*
* @author Michael Becke
* @author <a href="mailto:oleg@ural.ru">Oleg Kalnichevski</a>
*
* @since 2.0beta1
*/
public class HttpParser {
/** Log object for this class. */
private static final Log LOG = LogFactory.getLog(HttpParser.class);
/**
* Constructor for HttpParser.
*/
private HttpParser() { }
/**
* Return byte array from an (unchunked) input stream.
* Stop reading when <tt>"\n"</tt> terminator encountered
* If the stream ends before the line terminator is found,
* the last part of the string will still be returned.
* If no input data available, <code>null</code> is returned.
*
* @param inputStream the stream to read from
*
* @throws IOException if an I/O problem occurs
* @return a byte array from the stream
*/
public static byte[] readRawLine(InputStream inputStream) throws IOException {
LOG.trace("enter HttpParser.readRawLine()");
ByteArrayOutputStream buf = new ByteArrayOutputStream();
int ch;
while ((ch = inputStream.read()) >= 0) {
buf.write(ch);
if (ch == '\n') { // be tolerant (RFC-2616 Section 19.3)
break;
}
}
if (buf.size() == 0) {
return null;
}
return buf.toByteArray();
}
/**
* Read up to <tt>"\n"</tt> from an (unchunked) input stream.
* If the stream ends before the line terminator is found,
* the last part of the string will still be returned.
* If no input data available, <code>null</code> is returned.
*
* @param inputStream the stream to read from
* @param charset charset of HTTP protocol elements
*
* @throws IOException if an I/O problem occurs
* @return a line from the stream
*
* @since 3.0
*/
public static String readLine(InputStream inputStream, String charset) throws IOException {
LOG.trace("enter HttpParser.readLine(InputStream, String)");
byte[] rawdata = readRawLine(inputStream);
if (rawdata == null) {
return null;
}
// strip CR and LF from the end
int len = rawdata.length;
int offset = 0;
if (len > 0) {
if (rawdata[len - 1] == '\n') {
offset++;
if (len > 1) {
if (rawdata[len - 2] == '\r') {
offset++;
}
}
}
}
final String result =
EncodingUtil.getString(rawdata, 0, len - offset, charset);
if (Wire.HEADER_WIRE.enabled()) {
String logoutput = result;
if (offset == 2)
logoutput = result + "\r\n";
else if (offset == 1)
logoutput = result + "\n";
Wire.HEADER_WIRE.input(logoutput);
}
return result;
}
/**
* Read up to <tt>"\n"</tt> from an (unchunked) input stream.
* If the stream ends before the line terminator is found,
* the last part of the string will still be returned.
* If no input data available, <code>null</code> is returned
*
* @param inputStream the stream to read from
*
* @throws IOException if an I/O problem occurs
* @return a line from the stream
*
* @deprecated use #readLine(InputStream, String)
*/
public static String readLine(InputStream inputStream) throws IOException {
LOG.trace("enter HttpParser.readLine(InputStream)");
return readLine(inputStream, "US-ASCII");
}
/**
* Parses headers from the given stream. Headers with the same name are not
* combined.
*
* @param is the stream to read headers from
* @param charset the charset to use for reading the data
*
* @return an array of headers in the order in which they were parsed
*
* @throws IOException if an IO error occurs while reading from the stream
* @throws HttpException if there is an error parsing a header value
*
* @since 3.0
*/
public static Header[] parseHeaders(InputStream is, String charset) throws IOException, HttpException {
LOG.trace("enter HeaderParser.parseHeaders(InputStream, String)");
ArrayList headers = new ArrayList();
String name = null;
StringBuffer value = null;
for (; ;) {
String line = HttpParser.readLine(is, charset);
if ((line == null) || (line.trim().length() < 1)) {
break;
}
// Parse the header name and value
// Check for folded headers first
// Detect LWS-char see HTTP/1.0 or HTTP/1.1 Section 2.2
// discussion on folded headers
if ((line.charAt(0) == ' ') || (line.charAt(0) == '\t')) {
// we have continuation folded header
// so append value
if (value != null) {
value.append(' ');
value.append(line.trim());
}
} else {
// make sure we save the previous name,value pair if present
if (name != null) {
headers.add(new Header(name, value.toString()));
}
// Otherwise we should have normal HTTP header line
// Parse the header name and value
int colon = line.indexOf(":");
if (colon < 0) {
throw new ProtocolException("Unable to parse header: " + line);
}
name = line.substring(0, colon).trim();
value = new StringBuffer(line.substring(colon + 1).trim());
}
}
// make sure we save the last name,value pair if present
if (name != null) {
headers.add(new Header(name, value.toString()));
}
return (Header[]) headers.toArray(new Header[headers.size()]);
}
/**
* Parses headers from the given stream. Headers with the same name are not
* combined.
*
* @param is the stream to read headers from
*
* @return an array of headers in the order in which they were parsed
*
* @throws IOException if an IO error occurs while reading from the stream
* @throws HttpException if there is an error parsing a header value
*
* @deprecated use #parseHeaders(InputStream, String)
*/
public static Header[] parseHeaders(InputStream is) throws IOException, HttpException {
LOG.trace("enter HeaderParser.parseHeaders(InputStream, String)");
return parseHeaders(is, "US-ASCII");
}
}