/*
* ====================================================================
* 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 java.util.ArrayList;
import java.util.BitSet;
import java.util.List;
import org.apache.http.HeaderElement;
import org.apache.http.NameValuePair;
import org.apache.http.ParseException;
import org.apache.http.annotation.Immutable;
import org.apache.http.util.Args;
import org.apache.http.util.CharArrayBuffer;
/**
* Basic implementation for parsing header values into elements.
* Instances of this class are stateless and thread-safe.
* Derived classes are expected to maintain these properties.
*
* @since 4.0
*/
@Immutable
public class BasicHeaderValueParser implements HeaderValueParser {
/**
* A default instance of this class, for use as default or fallback.
* Note that {@link BasicHeaderValueParser} 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.
*
* @deprecated (4.3) use {@link #INSTANCE}
*/
@Deprecated
public final static
BasicHeaderValueParser DEFAULT = new BasicHeaderValueParser();
public final static BasicHeaderValueParser INSTANCE = new BasicHeaderValueParser();
private final static char PARAM_DELIMITER = ';';
private final static char ELEM_DELIMITER = ',';
// IMPORTANT!
// These private static variables must be treated as immutable and never exposed outside this class
private static final BitSet TOKEN_DELIMS = TokenParser.INIT_BITSET('=', PARAM_DELIMITER, ELEM_DELIMITER);
private static final BitSet VALUE_DELIMS = TokenParser.INIT_BITSET(PARAM_DELIMITER, ELEM_DELIMITER);
private final TokenParser tokenParser;
public BasicHeaderValueParser() {
this.tokenParser = TokenParser.INSTANCE;
}
/**
* Parses elements with the given parser.
*
* @param value the header value to parse
* @param parser the parser to use, or {@code null} for default
*
* @return array holding the header elements, never {@code null}
* @throws ParseException in case of a parsing error
*/
public static
HeaderElement[] parseElements(final String value,
final HeaderValueParser parser) throws ParseException {
Args.notNull(value, "Value");
final CharArrayBuffer buffer = new CharArrayBuffer(value.length());
buffer.append(value);
final ParserCursor cursor = new ParserCursor(0, value.length());
return (parser != null ? parser : BasicHeaderValueParser.INSTANCE)
.parseElements(buffer, cursor);
}
// non-javadoc, see interface HeaderValueParser
@Override
public HeaderElement[] parseElements(final CharArrayBuffer buffer,
final ParserCursor cursor) {
Args.notNull(buffer, "Char array buffer");
Args.notNull(cursor, "Parser cursor");
final List<HeaderElement> elements = new ArrayList<HeaderElement>();
while (!cursor.atEnd()) {
final HeaderElement element = parseHeaderElement(buffer, cursor);
if (!(element.getName().length() == 0 && element.getValue() == null)) {
elements.add(element);
}
}
return elements.toArray(new HeaderElement[elements.size()]);
}
/**
* Parses an element with the given parser.
*
* @param value the header element to parse
* @param parser the parser to use, or {@code null} for default
*
* @return the parsed header element
*/
public static
HeaderElement parseHeaderElement(final String value,
final HeaderValueParser parser) throws ParseException {
Args.notNull(value, "Value");
final CharArrayBuffer buffer = new CharArrayBuffer(value.length());
buffer.append(value);
final ParserCursor cursor = new ParserCursor(0, value.length());
return (parser != null ? parser : BasicHeaderValueParser.INSTANCE)
.parseHeaderElement(buffer, cursor);
}
// non-javadoc, see interface HeaderValueParser
@Override
public HeaderElement parseHeaderElement(final CharArrayBuffer buffer,
final ParserCursor cursor) {
Args.notNull(buffer, "Char array buffer");
Args.notNull(cursor, "Parser cursor");
final NameValuePair nvp = parseNameValuePair(buffer, cursor);
NameValuePair[] params = null;
if (!cursor.atEnd()) {
final char ch = buffer.charAt(cursor.getPos() - 1);
if (ch != ELEM_DELIMITER) {
params = parseParameters(buffer, cursor);
}
}
return createHeaderElement(nvp.getName(), nvp.getValue(), params);
}
/**
* Creates a header element.
* Called from {@link #parseHeaderElement}.
*
* @return a header element representing the argument
*/
protected HeaderElement createHeaderElement(
final String name,
final String value,
final NameValuePair[] params) {
return new BasicHeaderElement(name, value, params);
}
/**
* Parses parameters with the given parser.
*
* @param value the parameter list to parse
* @param parser the parser to use, or {@code null} for default
*
* @return array holding the parameters, never {@code null}
*/
public static
NameValuePair[] parseParameters(final String value,
final HeaderValueParser parser) throws ParseException {
Args.notNull(value, "Value");
final CharArrayBuffer buffer = new CharArrayBuffer(value.length());
buffer.append(value);
final ParserCursor cursor = new ParserCursor(0, value.length());
return (parser != null ? parser : BasicHeaderValueParser.INSTANCE)
.parseParameters(buffer, cursor);
}
// non-javadoc, see interface HeaderValueParser
@Override
public NameValuePair[] parseParameters(final CharArrayBuffer buffer,
final ParserCursor cursor) {
Args.notNull(buffer, "Char array buffer");
Args.notNull(cursor, "Parser cursor");
tokenParser.skipWhiteSpace(buffer, cursor);
final List<NameValuePair> params = new ArrayList<NameValuePair>();
while (!cursor.atEnd()) {
final NameValuePair param = parseNameValuePair(buffer, cursor);
params.add(param);
final char ch = buffer.charAt(cursor.getPos() - 1);
if (ch == ELEM_DELIMITER) {
break;
}
}
return params.toArray(new NameValuePair[params.size()]);
}
/**
* Parses a name-value-pair with the given parser.
*
* @param value the NVP to parse
* @param parser the parser to use, or {@code null} for default
*
* @return the parsed name-value pair
*/
public static
NameValuePair parseNameValuePair(final String value,
final HeaderValueParser parser) throws ParseException {
Args.notNull(value, "Value");
final CharArrayBuffer buffer = new CharArrayBuffer(value.length());
buffer.append(value);
final ParserCursor cursor = new ParserCursor(0, value.length());
return (parser != null ? parser : BasicHeaderValueParser.INSTANCE)
.parseNameValuePair(buffer, cursor);
}
// non-javadoc, see interface HeaderValueParser
@Override
public NameValuePair parseNameValuePair(final CharArrayBuffer buffer,
final ParserCursor cursor) {
Args.notNull(buffer, "Char array buffer");
Args.notNull(cursor, "Parser cursor");
final String name = tokenParser.parseToken(buffer, cursor, TOKEN_DELIMS);
if (cursor.atEnd()) {
return new BasicNameValuePair(name, null);
}
final int delim = buffer.charAt(cursor.getPos());
cursor.updatePos(cursor.getPos() + 1);
if (delim != '=') {
return createNameValuePair(name, null);
}
final String value = tokenParser.parseValue(buffer, cursor, VALUE_DELIMS);
if (!cursor.atEnd()) {
cursor.updatePos(cursor.getPos() + 1);
}
return createNameValuePair(name, value);
}
/**
* @deprecated (4.4) use {@link org.apache.http.message.TokenParser}
*/
@Deprecated
public NameValuePair parseNameValuePair(final CharArrayBuffer buffer,
final ParserCursor cursor,
final char[] delimiters) {
Args.notNull(buffer, "Char array buffer");
Args.notNull(cursor, "Parser cursor");
final BitSet delimSet = new BitSet();
if (delimiters != null) {
for (char delimiter: delimiters) {
delimSet.set(delimiter);
}
}
delimSet.set('=');
final String name = tokenParser.parseToken(buffer, cursor, delimSet);
if (cursor.atEnd()) {
return new BasicNameValuePair(name, null);
}
final int delim = buffer.charAt(cursor.getPos());
cursor.updatePos(cursor.getPos() + 1);
if (delim != '=') {
return createNameValuePair(name, null);
}
delimSet.clear('=');
final String value = tokenParser.parseValue(buffer, cursor, delimSet);
if (!cursor.atEnd()) {
cursor.updatePos(cursor.getPos() + 1);
}
return createNameValuePair(name, value);
}
/**
* Creates a name-value pair.
* Called from {@link #parseNameValuePair}.
*
* @param name the name
* @param value the value, or {@code null}
*
* @return a name-value pair representing the arguments
*/
protected NameValuePair createNameValuePair(final String name, final String value) {
return new BasicNameValuePair(name, value);
}
}