/*
* $HeadURL: http://svn.apache.org/repos/asf/httpcomponents/httpcore/trunk/module-main/src/main/java/org/apache/http/message/BasicLineParser.java $
* $Revision: 591798 $
* $Date: 2007-11-04 08:19:29 -0800 (Sun, 04 Nov 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.http.message;
import org.apache.http.HttpVersion;
import org.apache.http.ProtocolVersion;
import org.apache.http.ParseException;
import org.apache.http.RequestLine;
import org.apache.http.StatusLine;
import org.apache.http.Header;
import org.apache.http.protocol.HTTP;
import org.apache.http.util.CharArrayBuffer;
/**
* Basic parser for lines in the head section of an HTTP message.
* There are individual methods for parsing a request line, a
* status line, or a header line.
* The lines to parse are passed in memory, the parser does not depend
* on any specific IO mechanism.
* Instances of this class are stateless and thread-safe.
* Derived classes MUST maintain these properties.
*
* <p>
* Note: This class was created by refactoring parsing code located in
* various other classes. The author tags from those other classes have
* been replicated here, although the association with the parsing code
* taken from there has not been traced.
* </p>
*
* @author <a href="mailto:jsdever@apache.org">Jeff Dever</a>
* @author <a href="mailto:mbowler@GargoyleSoftware.com">Mike Bowler</a>
* @author <a href="mailto:oleg@ural.ru">Oleg Kalnichevski</a>
* @author and others
*/
public class BasicLineParser implements LineParser {
/**
* A default instance of this class, for use as default or fallback.
* Note that {@link BasicLineParser} is not a singleton, there can
* be many instances of the class itself and of derived classes.
* The instance here provides non-customized, default behavior.
*/
public final static BasicLineParser DEFAULT = new BasicLineParser();
/**
* A version of the protocol to parse.
* The version is typically not relevant, but the protocol name.
*/
protected final ProtocolVersion protocol;
/**
* Creates a new line parser for the given HTTP-like protocol.
*
* @param proto a version of the protocol to parse, or
* <code>null</code> for HTTP. The actual version
* is not relevant, only the protocol name.
*/
public BasicLineParser(ProtocolVersion proto) {
if (proto == null) {
proto = HttpVersion.HTTP_1_1;
}
this.protocol = proto;
}
/**
* Creates a new line parser for HTTP.
*/
public BasicLineParser() {
this(null);
}
public final static
ProtocolVersion parseProtocolVersion(String value,
LineParser parser)
throws ParseException {
if (value == null) {
throw new IllegalArgumentException
("Value to parse may not be null.");
}
if (parser == null)
parser = BasicLineParser.DEFAULT;
CharArrayBuffer buffer = new CharArrayBuffer(value.length());
buffer.append(value);
ParserCursor cursor = new ParserCursor(0, value.length());
return parser.parseProtocolVersion(buffer, cursor);
}
// non-javadoc, see interface LineParser
public ProtocolVersion parseProtocolVersion(final CharArrayBuffer buffer,
final ParserCursor cursor)
throws ParseException {
if (buffer == null) {
throw new IllegalArgumentException("Char array buffer may not be null");
}
if (cursor == null) {
throw new IllegalArgumentException("Parser cursor may not be null");
}
final String protoname = this.protocol.getProtocol();
final int protolength = protoname.length();
int indexFrom = cursor.getPos();
int indexTo = cursor.getUpperBound();
skipWhitespace(buffer, cursor);
int i = cursor.getPos();
// long enough for "HTTP/1.1"?
if (i + protolength + 4 > indexTo) {
throw new ParseException
("Not a valid protocol version: " +
buffer.substring(indexFrom, indexTo));
}
// check the protocol name and slash
boolean ok = true;
for (int j=0; ok && (j<protolength); j++) {
ok = (buffer.charAt(i+j) == protoname.charAt(j));
}
if (ok) {
ok = (buffer.charAt(i+protolength) == '/');
}
if (!ok) {
throw new ParseException
("Not a valid protocol version: " +
buffer.substring(indexFrom, indexTo));
}
i += protolength+1;
int period = buffer.indexOf('.', i, indexTo);
if (period == -1) {
throw new ParseException
("Invalid protocol version number: " +
buffer.substring(indexFrom, indexTo));
}
int major;
try {
major = Integer.parseInt(buffer.substringTrimmed(i, period));
} catch (NumberFormatException e) {
throw new ParseException
("Invalid protocol major version number: " +
buffer.substring(indexFrom, indexTo));
}
i = period + 1;
int blank = buffer.indexOf(' ', i, indexTo);
if (blank == -1) {
blank = indexTo;
}
int minor;
try {
minor = Integer.parseInt(buffer.substringTrimmed(i, blank));
} catch (NumberFormatException e) {
throw new ParseException(
"Invalid protocol minor version number: " +
buffer.substring(indexFrom, indexTo));
}
cursor.updatePos(blank);
return createProtocolVersion(major, minor);
} // parseProtocolVersion
/**
* Creates a protocol version.
* Called from {@link #parseProtocolVersion}.
*
* @param major the major version number, for example 1 in HTTP/1.0
* @param minor the minor version number, for example 0 in HTTP/1.0
*
* @return the protocol version
*/
protected ProtocolVersion createProtocolVersion(int major, int minor) {
return protocol.forVersion(major, minor);
}
// non-javadoc, see interface LineParser
public boolean hasProtocolVersion(final CharArrayBuffer buffer,
final ParserCursor cursor) {
if (buffer == null) {
throw new IllegalArgumentException("Char array buffer may not be null");
}
if (cursor == null) {
throw new IllegalArgumentException("Parser cursor may not be null");
}
int index = cursor.getPos();
final String protoname = this.protocol.getProtocol();
final int protolength = protoname.length();
if (buffer.length() < protolength+4)
return false; // not long enough for "HTTP/1.1"
if (index < 0) {
// end of line, no tolerance for trailing whitespace
// this works only for single-digit major and minor version
index = buffer.length() -4 -protolength;
} else if (index == 0) {
// beginning of line, tolerate leading whitespace
while ((index < buffer.length()) &&
HTTP.isWhitespace(buffer.charAt(index))) {
index++;
}
} // else within line, don't tolerate whitespace
if (index + protolength + 4 > buffer.length())
return false;
// just check protocol name and slash, no need to analyse the version
boolean ok = true;
for (int j=0; ok && (j<protolength); j++) {
ok = (buffer.charAt(index+j) == protoname.charAt(j));
}
if (ok) {
ok = (buffer.charAt(index+protolength) == '/');
}
return ok;
}
public final static
RequestLine parseRequestLine(final String value,
LineParser parser)
throws ParseException {
if (value == null) {
throw new IllegalArgumentException
("Value to parse may not be null.");
}
if (parser == null)
parser = BasicLineParser.DEFAULT;
CharArrayBuffer buffer = new CharArrayBuffer(value.length());
buffer.append(value);
ParserCursor cursor = new ParserCursor(0, value.length());
return parser.parseRequestLine(buffer, cursor);
}
/**
* Parses a request line.
*
* @param buffer a buffer holding the line to parse
*
* @return the parsed request line
*
* @throws ParseException in case of a parse error
*/
public RequestLine parseRequestLine(final CharArrayBuffer buffer,
final ParserCursor cursor)
throws ParseException {
if (buffer == null) {
throw new IllegalArgumentException("Char array buffer may not be null");
}
if (cursor == null) {
throw new IllegalArgumentException("Parser cursor may not be null");
}
int indexFrom = cursor.getPos();
int indexTo = cursor.getUpperBound();
try {
skipWhitespace(buffer, cursor);
int i = cursor.getPos();
int blank = buffer.indexOf(' ', i, indexTo);
if (blank < 0) {
throw new ParseException("Invalid request line: " +
buffer.substring(indexFrom, indexTo));
}
String method = buffer.substringTrimmed(i, blank);
cursor.updatePos(blank);
skipWhitespace(buffer, cursor);
i = cursor.getPos();
blank = buffer.indexOf(' ', i, indexTo);
if (blank < 0) {
throw new ParseException("Invalid request line: " +
buffer.substring(indexFrom, indexTo));
}
String uri = buffer.substringTrimmed(i, blank);
cursor.updatePos(blank);
ProtocolVersion ver = parseProtocolVersion(buffer, cursor);
skipWhitespace(buffer, cursor);
if (!cursor.atEnd()) {
throw new ParseException("Invalid request line: " +
buffer.substring(indexFrom, indexTo));
}
return createRequestLine(method, uri, ver);
} catch (IndexOutOfBoundsException e) {
throw new ParseException("Invalid request line: " +
buffer.substring(indexFrom, indexTo));
}
} // parseRequestLine
/**
* Instantiates a new request line.
* Called from {@link #parseRequestLine}.
*
* @param method the request method
* @param uri the requested URI
* @param ver the protocol version
*
* @return a new status line with the given data
*/
protected RequestLine createRequestLine(final String method,
final String uri,
final ProtocolVersion ver) {
return new BasicRequestLine(method, uri, ver);
}
public final static
StatusLine parseStatusLine(final String value,
LineParser parser)
throws ParseException {
if (value == null) {
throw new IllegalArgumentException
("Value to parse may not be null.");
}
if (parser == null)
parser = BasicLineParser.DEFAULT;
CharArrayBuffer buffer = new CharArrayBuffer(value.length());
buffer.append(value);
ParserCursor cursor = new ParserCursor(0, value.length());
return parser.parseStatusLine(buffer, cursor);
}
// non-javadoc, see interface LineParser
public StatusLine parseStatusLine(final CharArrayBuffer buffer,
final ParserCursor cursor)
throws ParseException {
if (buffer == null) {
throw new IllegalArgumentException("Char array buffer may not be null");
}
if (cursor == null) {
throw new IllegalArgumentException("Parser cursor may not be null");
}
int indexFrom = cursor.getPos();
int indexTo = cursor.getUpperBound();
try {
// handle the HTTP-Version
ProtocolVersion ver = parseProtocolVersion(buffer, cursor);
// handle the Status-Code
skipWhitespace(buffer, cursor);
int i = cursor.getPos();
int blank = buffer.indexOf(' ', i, indexTo);
if (blank < 0) {
blank = indexTo;
}
int statusCode = 0;
try {
statusCode =
Integer.parseInt(buffer.substringTrimmed(i, blank));
} catch (NumberFormatException e) {
throw new ParseException(
"Unable to parse status code from status line: "
+ buffer.substring(indexFrom, indexTo));
}
//handle the Reason-Phrase
i = blank;
String reasonPhrase = null;
if (i < indexTo) {
reasonPhrase = buffer.substringTrimmed(i, indexTo);
} else {
reasonPhrase = "";
}
return createStatusLine(ver, statusCode, reasonPhrase);
} catch (IndexOutOfBoundsException e) {
throw new ParseException("Invalid status line: " +
buffer.substring(indexFrom, indexTo));
}
} // parseStatusLine
/**
* Instantiates a new status line.
* Called from {@link #parseStatusLine}.
*
* @param ver the protocol version
* @param status the status code
* @param reason the reason phrase
*
* @return a new status line with the given data
*/
protected StatusLine createStatusLine(final ProtocolVersion ver,
final int status,
final String reason) {
return new BasicStatusLine(ver, status, reason);
}
public final static
Header parseHeader(final String value,
LineParser parser)
throws ParseException {
if (value == null) {
throw new IllegalArgumentException
("Value to parse may not be null");
}
if (parser == null)
parser = BasicLineParser.DEFAULT;
CharArrayBuffer buffer = new CharArrayBuffer(value.length());
buffer.append(value);
return parser.parseHeader(buffer);
}
// non-javadoc, see interface LineParser
public Header parseHeader(CharArrayBuffer buffer)
throws ParseException {
// the actual parser code is in the constructor of BufferedHeader
return new BufferedHeader(buffer);
}
/**
* Helper to skip whitespace.
*/
protected void skipWhitespace(final CharArrayBuffer buffer, final ParserCursor cursor) {
int pos = cursor.getPos();
int indexTo = cursor.getUpperBound();
while ((pos < indexTo) &&
HTTP.isWhitespace(buffer.charAt(pos))) {
pos++;
}
cursor.updatePos(pos);
}
} // class BasicLineParser