michael@0: /*
michael@0:  * ====================================================================
michael@0:  * Licensed to the Apache Software Foundation (ASF) under one
michael@0:  * or more contributor license agreements.  See the NOTICE file
michael@0:  * distributed with this work for additional information
michael@0:  * regarding copyright ownership.  The ASF licenses this file
michael@0:  * to you under the Apache License, Version 2.0 (the
michael@0:  * "License"); you may not use this file except in compliance
michael@0:  * with the License.  You may obtain a copy of the License at
michael@0:  *
michael@0:  *   http://www.apache.org/licenses/LICENSE-2.0
michael@0:  *
michael@0:  * Unless required by applicable law or agreed to in writing,
michael@0:  * software distributed under the License is distributed on an
michael@0:  * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
michael@0:  * KIND, either express or implied.  See the License for the
michael@0:  * specific language governing permissions and limitations
michael@0:  * under the License.
michael@0:  * ====================================================================
michael@0:  *
michael@0:  * This software consists of voluntary contributions made by many
michael@0:  * individuals on behalf of the Apache Software Foundation.  For more
michael@0:  * information on the Apache Software Foundation, please see
michael@0:  * <http://www.apache.org/>.
michael@0:  *
michael@0:  */
michael@0: 
michael@0: package ch.boye.httpclientandroidlib.message;
michael@0: 
michael@0: import java.util.List;
michael@0: import java.util.ArrayList;
michael@0: 
michael@0: import ch.boye.httpclientandroidlib.HeaderElement;
michael@0: import ch.boye.httpclientandroidlib.NameValuePair;
michael@0: import ch.boye.httpclientandroidlib.ParseException;
michael@0: import ch.boye.httpclientandroidlib.protocol.HTTP;
michael@0: import ch.boye.httpclientandroidlib.util.CharArrayBuffer;
michael@0: 
michael@0: /**
michael@0:  * Basic implementation for parsing header values into elements.
michael@0:  * Instances of this class are stateless and thread-safe.
michael@0:  * Derived classes are expected to maintain these properties.
michael@0:  *
michael@0:  * @since 4.0
michael@0:  */
michael@0: public class BasicHeaderValueParser implements HeaderValueParser {
michael@0: 
michael@0:     /**
michael@0:      * A default instance of this class, for use as default or fallback.
michael@0:      * Note that {@link BasicHeaderValueParser} is not a singleton, there
michael@0:      * can be many instances of the class itself and of derived classes.
michael@0:      * The instance here provides non-customized, default behavior.
michael@0:      */
michael@0:     public final static
michael@0:         BasicHeaderValueParser DEFAULT = new BasicHeaderValueParser();
michael@0: 
michael@0:     private final static char PARAM_DELIMITER                = ';';
michael@0:     private final static char ELEM_DELIMITER                 = ',';
michael@0:     private final static char[] ALL_DELIMITERS               = new char[] {
michael@0:                                                                 PARAM_DELIMITER,
michael@0:                                                                 ELEM_DELIMITER
michael@0:                                                                 };
michael@0: 
michael@0:     // public default constructor
michael@0: 
michael@0: 
michael@0:     /**
michael@0:      * Parses elements with the given parser.
michael@0:      *
michael@0:      * @param value     the header value to parse
michael@0:      * @param parser    the parser to use, or <code>null</code> for default
michael@0:      *
michael@0:      * @return  array holding the header elements, never <code>null</code>
michael@0:      */
michael@0:     public final static
michael@0:         HeaderElement[] parseElements(final String value,
michael@0:                                       HeaderValueParser parser)
michael@0:         throws ParseException {
michael@0: 
michael@0:         if (value == null) {
michael@0:             throw new IllegalArgumentException
michael@0:                 ("Value to parse may not be null");
michael@0:         }
michael@0: 
michael@0:         if (parser == null)
michael@0:             parser = BasicHeaderValueParser.DEFAULT;
michael@0: 
michael@0:         CharArrayBuffer buffer = new CharArrayBuffer(value.length());
michael@0:         buffer.append(value);
michael@0:         ParserCursor cursor = new ParserCursor(0, value.length());
michael@0:         return parser.parseElements(buffer, cursor);
michael@0:     }
michael@0: 
michael@0: 
michael@0:     // non-javadoc, see interface HeaderValueParser
michael@0:     public HeaderElement[] parseElements(final CharArrayBuffer buffer,
michael@0:                                          final ParserCursor cursor) {
michael@0: 
michael@0:         if (buffer == null) {
michael@0:             throw new IllegalArgumentException("Char array buffer may not be null");
michael@0:         }
michael@0:         if (cursor == null) {
michael@0:             throw new IllegalArgumentException("Parser cursor may not be null");
michael@0:         }
michael@0: 
michael@0:         List elements = new ArrayList();
michael@0:         while (!cursor.atEnd()) {
michael@0:             HeaderElement element = parseHeaderElement(buffer, cursor);
michael@0:             if (!(element.getName().length() == 0 && element.getValue() == null)) {
michael@0:                 elements.add(element);
michael@0:             }
michael@0:         }
michael@0:         return (HeaderElement[])
michael@0:             elements.toArray(new HeaderElement[elements.size()]);
michael@0:     }
michael@0: 
michael@0: 
michael@0:     /**
michael@0:      * Parses an element with the given parser.
michael@0:      *
michael@0:      * @param value     the header element to parse
michael@0:      * @param parser    the parser to use, or <code>null</code> for default
michael@0:      *
michael@0:      * @return  the parsed header element
michael@0:      */
michael@0:     public final static
michael@0:         HeaderElement parseHeaderElement(final String value,
michael@0:                                          HeaderValueParser parser)
michael@0:         throws ParseException {
michael@0: 
michael@0:         if (value == null) {
michael@0:             throw new IllegalArgumentException
michael@0:                 ("Value to parse may not be null");
michael@0:         }
michael@0: 
michael@0:         if (parser == null)
michael@0:             parser = BasicHeaderValueParser.DEFAULT;
michael@0: 
michael@0:         CharArrayBuffer buffer = new CharArrayBuffer(value.length());
michael@0:         buffer.append(value);
michael@0:         ParserCursor cursor = new ParserCursor(0, value.length());
michael@0:         return parser.parseHeaderElement(buffer, cursor);
michael@0:     }
michael@0: 
michael@0: 
michael@0:     // non-javadoc, see interface HeaderValueParser
michael@0:     public HeaderElement parseHeaderElement(final CharArrayBuffer buffer,
michael@0:                                             final ParserCursor cursor) {
michael@0: 
michael@0:         if (buffer == null) {
michael@0:             throw new IllegalArgumentException("Char array buffer may not be null");
michael@0:         }
michael@0:         if (cursor == null) {
michael@0:             throw new IllegalArgumentException("Parser cursor may not be null");
michael@0:         }
michael@0: 
michael@0:         NameValuePair nvp = parseNameValuePair(buffer, cursor);
michael@0:         NameValuePair[] params = null;
michael@0:         if (!cursor.atEnd()) {
michael@0:             char ch = buffer.charAt(cursor.getPos() - 1);
michael@0:             if (ch != ELEM_DELIMITER) {
michael@0:                 params = parseParameters(buffer, cursor);
michael@0:             }
michael@0:         }
michael@0:         return createHeaderElement(nvp.getName(), nvp.getValue(), params);
michael@0:     }
michael@0: 
michael@0: 
michael@0:     /**
michael@0:      * Creates a header element.
michael@0:      * Called from {@link #parseHeaderElement}.
michael@0:      *
michael@0:      * @return  a header element representing the argument
michael@0:      */
michael@0:     protected HeaderElement createHeaderElement(
michael@0:             final String name,
michael@0:             final String value,
michael@0:             final NameValuePair[] params) {
michael@0:         return new BasicHeaderElement(name, value, params);
michael@0:     }
michael@0: 
michael@0: 
michael@0:     /**
michael@0:      * Parses parameters with the given parser.
michael@0:      *
michael@0:      * @param value     the parameter list to parse
michael@0:      * @param parser    the parser to use, or <code>null</code> for default
michael@0:      *
michael@0:      * @return  array holding the parameters, never <code>null</code>
michael@0:      */
michael@0:     public final static
michael@0:         NameValuePair[] parseParameters(final String value,
michael@0:                                         HeaderValueParser parser)
michael@0:         throws ParseException {
michael@0: 
michael@0:         if (value == null) {
michael@0:             throw new IllegalArgumentException
michael@0:                 ("Value to parse may not be null");
michael@0:         }
michael@0: 
michael@0:         if (parser == null)
michael@0:             parser = BasicHeaderValueParser.DEFAULT;
michael@0: 
michael@0:         CharArrayBuffer buffer = new CharArrayBuffer(value.length());
michael@0:         buffer.append(value);
michael@0:         ParserCursor cursor = new ParserCursor(0, value.length());
michael@0:         return parser.parseParameters(buffer, cursor);
michael@0:     }
michael@0: 
michael@0: 
michael@0: 
michael@0:     // non-javadoc, see interface HeaderValueParser
michael@0:     public NameValuePair[] parseParameters(final CharArrayBuffer buffer,
michael@0:                                            final ParserCursor cursor) {
michael@0: 
michael@0:         if (buffer == null) {
michael@0:             throw new IllegalArgumentException("Char array buffer may not be null");
michael@0:         }
michael@0:         if (cursor == null) {
michael@0:             throw new IllegalArgumentException("Parser cursor may not be null");
michael@0:         }
michael@0: 
michael@0:         int pos = cursor.getPos();
michael@0:         int indexTo = cursor.getUpperBound();
michael@0: 
michael@0:         while (pos < indexTo) {
michael@0:             char ch = buffer.charAt(pos);
michael@0:             if (HTTP.isWhitespace(ch)) {
michael@0:                 pos++;
michael@0:             } else {
michael@0:                 break;
michael@0:             }
michael@0:         }
michael@0:         cursor.updatePos(pos);
michael@0:         if (cursor.atEnd()) {
michael@0:             return new NameValuePair[] {};
michael@0:         }
michael@0: 
michael@0:         List params = new ArrayList();
michael@0:         while (!cursor.atEnd()) {
michael@0:             NameValuePair param = parseNameValuePair(buffer, cursor);
michael@0:             params.add(param);
michael@0:             char ch = buffer.charAt(cursor.getPos() - 1);
michael@0:             if (ch == ELEM_DELIMITER) {
michael@0:                 break;
michael@0:             }
michael@0:         }
michael@0: 
michael@0:         return (NameValuePair[])
michael@0:             params.toArray(new NameValuePair[params.size()]);
michael@0:     }
michael@0: 
michael@0:     /**
michael@0:      * Parses a name-value-pair with the given parser.
michael@0:      *
michael@0:      * @param value     the NVP to parse
michael@0:      * @param parser    the parser to use, or <code>null</code> for default
michael@0:      *
michael@0:      * @return  the parsed name-value pair
michael@0:      */
michael@0:     public final static
michael@0:        NameValuePair parseNameValuePair(final String value,
michael@0:                                         HeaderValueParser parser)
michael@0:         throws ParseException {
michael@0: 
michael@0:         if (value == null) {
michael@0:             throw new IllegalArgumentException
michael@0:                 ("Value to parse may not be null");
michael@0:         }
michael@0: 
michael@0:         if (parser == null)
michael@0:             parser = BasicHeaderValueParser.DEFAULT;
michael@0: 
michael@0:         CharArrayBuffer buffer = new CharArrayBuffer(value.length());
michael@0:         buffer.append(value);
michael@0:         ParserCursor cursor = new ParserCursor(0, value.length());
michael@0:         return parser.parseNameValuePair(buffer, cursor);
michael@0:     }
michael@0: 
michael@0: 
michael@0:     // non-javadoc, see interface HeaderValueParser
michael@0:     public NameValuePair parseNameValuePair(final CharArrayBuffer buffer,
michael@0:                                             final ParserCursor cursor) {
michael@0:         return parseNameValuePair(buffer, cursor, ALL_DELIMITERS);
michael@0:     }
michael@0: 
michael@0:     private static boolean isOneOf(final char ch, final char[] chs) {
michael@0:         if (chs != null) {
michael@0:             for (int i = 0; i < chs.length; i++) {
michael@0:                 if (ch == chs[i]) {
michael@0:                     return true;
michael@0:                 }
michael@0:             }
michael@0:         }
michael@0:         return false;
michael@0:     }
michael@0: 
michael@0:     public NameValuePair parseNameValuePair(final CharArrayBuffer buffer,
michael@0:                                             final ParserCursor cursor,
michael@0:                                             final char[] delimiters) {
michael@0: 
michael@0:         if (buffer == null) {
michael@0:             throw new IllegalArgumentException("Char array buffer may not be null");
michael@0:         }
michael@0:         if (cursor == null) {
michael@0:             throw new IllegalArgumentException("Parser cursor may not be null");
michael@0:         }
michael@0: 
michael@0:         boolean terminated = false;
michael@0: 
michael@0:         int pos = cursor.getPos();
michael@0:         int indexFrom = cursor.getPos();
michael@0:         int indexTo = cursor.getUpperBound();
michael@0: 
michael@0:         // Find name
michael@0:         String name = null;
michael@0:         while (pos < indexTo) {
michael@0:             char ch = buffer.charAt(pos);
michael@0:             if (ch == '=') {
michael@0:                 break;
michael@0:             }
michael@0:             if (isOneOf(ch, delimiters)) {
michael@0:                 terminated = true;
michael@0:                 break;
michael@0:             }
michael@0:             pos++;
michael@0:         }
michael@0: 
michael@0:         if (pos == indexTo) {
michael@0:             terminated = true;
michael@0:             name = buffer.substringTrimmed(indexFrom, indexTo);
michael@0:         } else {
michael@0:             name = buffer.substringTrimmed(indexFrom, pos);
michael@0:             pos++;
michael@0:         }
michael@0: 
michael@0:         if (terminated) {
michael@0:             cursor.updatePos(pos);
michael@0:             return createNameValuePair(name, null);
michael@0:         }
michael@0: 
michael@0:         // Find value
michael@0:         String value = null;
michael@0:         int i1 = pos;
michael@0: 
michael@0:         boolean qouted = false;
michael@0:         boolean escaped = false;
michael@0:         while (pos < indexTo) {
michael@0:             char ch = buffer.charAt(pos);
michael@0:             if (ch == '"' && !escaped) {
michael@0:                 qouted = !qouted;
michael@0:             }
michael@0:             if (!qouted && !escaped && isOneOf(ch, delimiters)) {
michael@0:                 terminated = true;
michael@0:                 break;
michael@0:             }
michael@0:             if (escaped) {
michael@0:                 escaped = false;
michael@0:             } else {
michael@0:                 escaped = qouted && ch == '\\';
michael@0:             }
michael@0:             pos++;
michael@0:         }
michael@0: 
michael@0:         int i2 = pos;
michael@0:         // Trim leading white spaces
michael@0:         while (i1 < i2 && (HTTP.isWhitespace(buffer.charAt(i1)))) {
michael@0:             i1++;
michael@0:         }
michael@0:         // Trim trailing white spaces
michael@0:         while ((i2 > i1) && (HTTP.isWhitespace(buffer.charAt(i2 - 1)))) {
michael@0:             i2--;
michael@0:         }
michael@0:         // Strip away quotes if necessary
michael@0:         if (((i2 - i1) >= 2)
michael@0:             && (buffer.charAt(i1) == '"')
michael@0:             && (buffer.charAt(i2 - 1) == '"')) {
michael@0:             i1++;
michael@0:             i2--;
michael@0:         }
michael@0:         value = buffer.substring(i1, i2);
michael@0:         if (terminated) {
michael@0:             pos++;
michael@0:         }
michael@0:         cursor.updatePos(pos);
michael@0:         return createNameValuePair(name, value);
michael@0:     }
michael@0: 
michael@0:     /**
michael@0:      * Creates a name-value pair.
michael@0:      * Called from {@link #parseNameValuePair}.
michael@0:      *
michael@0:      * @param name      the name
michael@0:      * @param value     the value, or <code>null</code>
michael@0:      *
michael@0:      * @return  a name-value pair representing the arguments
michael@0:      */
michael@0:     protected NameValuePair createNameValuePair(final String name, final String value) {
michael@0:         return new BasicNameValuePair(name, value);
michael@0:     }
michael@0: 
michael@0: }
michael@0: