/*
* ====================================================================
* 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.impl.io;
import java.io.
IOException;
import java.util.
ArrayList;
import java.util.
List;
import org.apache.http.
Header;
import org.apache.http.
HttpException;
import org.apache.http.
HttpMessage;
import org.apache.http.
MessageConstraintException;
import org.apache.http.
ParseException;
import org.apache.http.
ProtocolException;
import org.apache.http.config.
MessageConstraints;
import org.apache.http.io.
HttpMessageParser;
import org.apache.http.io.
SessionInputBuffer;
import org.apache.http.message.
BasicLineParser;
import org.apache.http.message.
LineParser;
import org.apache.http.params.
HttpParamConfig;
import org.apache.http.params.
HttpParams;
import org.apache.http.util.
Args;
import org.apache.http.util.
CharArrayBuffer;
/**
* Abstract base class for HTTP message parsers that obtain input from
* an instance of {@link SessionInputBuffer}.
*
* @since 4.0
*/
@
SuppressWarnings("deprecation")
public abstract class
AbstractMessageParser<T extends
HttpMessage> implements
HttpMessageParser<T> {
private static final int
HEAD_LINE = 0;
private static final int
HEADERS = 1;
private final
SessionInputBuffer sessionBuffer;
private final
MessageConstraints messageConstraints;
private final
List<
CharArrayBuffer>
headerLines;
protected final
LineParser lineParser;
private int
state;
private T
message;
/**
* Creates an instance of AbstractMessageParser.
*
* @param buffer the session input buffer.
* @param parser the line parser.
* @param params HTTP parameters.
*
* @deprecated (4.3) use {@link AbstractMessageParser#AbstractMessageParser(SessionInputBuffer,
* LineParser, MessageConstraints)}
*/
@
Deprecated
public
AbstractMessageParser(
final
SessionInputBuffer buffer,
final
LineParser parser,
final
HttpParams params) {
super();
Args.
notNull(
buffer, "Session input buffer");
Args.
notNull(
params, "HTTP parameters");
this.
sessionBuffer =
buffer;
this.
messageConstraints =
HttpParamConfig.
getMessageConstraints(
params);
this.
lineParser = (
parser != null) ?
parser :
BasicLineParser.
INSTANCE;
this.
headerLines = new
ArrayList<
CharArrayBuffer>();
this.
state =
HEAD_LINE;
}
/**
* Creates new instance of AbstractMessageParser.
*
* @param buffer the session input buffer.
* @param lineParser the line parser. If {@code null} {@link BasicLineParser#INSTANCE}
* will be used.
* @param constraints the message constraints. If {@code null}
* {@link MessageConstraints#DEFAULT} will be used.
*
* @since 4.3
*/
public
AbstractMessageParser(
final
SessionInputBuffer buffer,
final
LineParser lineParser,
final
MessageConstraints constraints) {
super();
this.
sessionBuffer =
Args.
notNull(
buffer, "Session input buffer");
this.
lineParser =
lineParser != null ?
lineParser :
BasicLineParser.
INSTANCE;
this.
messageConstraints =
constraints != null ?
constraints :
MessageConstraints.
DEFAULT;
this.
headerLines = new
ArrayList<
CharArrayBuffer>();
this.
state =
HEAD_LINE;
}
/**
* Parses HTTP headers from the data receiver stream according to the generic
* format as given in Section 3.1 of RFC 822, RFC-2616 Section 4 and 19.3.
*
* @param inbuffer Session input buffer
* @param maxHeaderCount maximum number of headers allowed. If the number
* of headers received from the data stream exceeds maxCount value, an
* IOException will be thrown. Setting this parameter to a negative value
* or zero will disable the check.
* @param maxLineLen maximum number of characters for a header line,
* including the continuation lines. Setting this parameter to a negative
* value or zero will disable the check.
* @return array of HTTP headers
* @param parser line parser to use. Can be {@code null}, in which case
* the default implementation of this interface will be used.
*
* @throws IOException in case of an I/O error
* @throws HttpException in case of HTTP protocol violation
*/
public static
Header[]
parseHeaders(
final
SessionInputBuffer inbuffer,
final int
maxHeaderCount,
final int
maxLineLen,
final
LineParser parser) throws
HttpException,
IOException {
final
List<
CharArrayBuffer>
headerLines = new
ArrayList<
CharArrayBuffer>();
return
parseHeaders(
inbuffer,
maxHeaderCount,
maxLineLen,
parser != null ?
parser :
BasicLineParser.
INSTANCE,
headerLines);
}
/**
* Parses HTTP headers from the data receiver stream according to the generic
* format as given in Section 3.1 of RFC 822, RFC-2616 Section 4 and 19.3.
*
* @param inbuffer Session input buffer
* @param maxHeaderCount maximum number of headers allowed. If the number
* of headers received from the data stream exceeds maxCount value, an
* IOException will be thrown. Setting this parameter to a negative value
* or zero will disable the check.
* @param maxLineLen maximum number of characters for a header line,
* including the continuation lines. Setting this parameter to a negative
* value or zero will disable the check.
* @param parser line parser to use.
* @param headerLines List of header lines. This list will be used to store
* intermediate results. This makes it possible to resume parsing of
* headers in case of a {@link java.io.InterruptedIOException}.
*
* @return array of HTTP headers
*
* @throws IOException in case of an I/O error
* @throws HttpException in case of HTTP protocol violation
*
* @since 4.1
*/
public static
Header[]
parseHeaders(
final
SessionInputBuffer inbuffer,
final int
maxHeaderCount,
final int
maxLineLen,
final
LineParser parser,
final
List<
CharArrayBuffer>
headerLines) throws
HttpException,
IOException {
Args.
notNull(
inbuffer, "Session input buffer");
Args.
notNull(
parser, "Line parser");
Args.
notNull(
headerLines, "Header line list");
CharArrayBuffer current = null;
CharArrayBuffer previous = null;
for (;;) {
if (
current == null) {
current = new
CharArrayBuffer(64);
} else {
current.
clear();
}
final int
l =
inbuffer.
readLine(
current);
if (
l == -1 ||
current.
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 ((
current.
charAt(0) == ' ' ||
current.
charAt(0) == '\t') &&
previous != null) {
// we have continuation folded header
// so append value
int
i = 0;
while (
i <
current.
length()) {
final char
ch =
current.
charAt(
i);
if (
ch != ' ' &&
ch != '\t') {
break;
}
i++;
}
if (
maxLineLen > 0
&&
previous.
length() + 1 +
current.
length() -
i >
maxLineLen) {
throw new
MessageConstraintException("Maximum line length limit exceeded");
}
previous.
append(' ');
previous.
append(
current,
i,
current.
length() -
i);
} else {
headerLines.
add(
current);
previous =
current;
current = null;
}
if (
maxHeaderCount > 0 &&
headerLines.
size() >=
maxHeaderCount) {
throw new
MessageConstraintException("Maximum header count exceeded");
}
}
final
Header[]
headers = new
Header[
headerLines.
size()];
for (int
i = 0;
i <
headerLines.
size();
i++) {
final
CharArrayBuffer buffer =
headerLines.
get(
i);
try {
headers[
i] =
parser.
parseHeader(
buffer);
} catch (final
ParseException ex) {
throw new
ProtocolException(
ex.
getMessage());
}
}
return
headers;
}
/**
* Subclasses must override this method to generate an instance of
* {@link HttpMessage} based on the initial input from the session buffer.
* <p>
* Usually this method is expected to read just the very first line or
* the very first valid from the data stream and based on the input generate
* an appropriate instance of {@link HttpMessage}.
*
* @param sessionBuffer the session input buffer.
* @return HTTP message based on the input from the session buffer.
* @throws IOException in case of an I/O error.
* @throws HttpException in case of HTTP protocol violation.
* @throws ParseException in case of a parse error.
*/
protected abstract T
parseHead(
SessionInputBuffer sessionBuffer)
throws
IOException,
HttpException,
ParseException;
@
Override
public T
parse() throws
IOException,
HttpException {
final int
st = this.
state;
switch (
st) {
case
HEAD_LINE:
try {
this.
message =
parseHead(this.
sessionBuffer);
} catch (final
ParseException px) {
throw new
ProtocolException(
px.
getMessage(),
px);
}
this.
state =
HEADERS;
//$FALL-THROUGH$
case
HEADERS:
final
Header[]
headers =
AbstractMessageParser.
parseHeaders(
this.
sessionBuffer,
this.
messageConstraints.
getMaxHeaderCount(),
this.
messageConstraints.
getMaxLineLength(),
this.
lineParser,
this.
headerLines);
this.
message.
setHeaders(
headers);
final T
result = this.
message;
this.
message = null;
this.
headerLines.
clear();
this.
state =
HEAD_LINE;
return
result;
default:
throw new
IllegalStateException("Inconsistent parser state");
}
}
}