aoqi@0: /*
aoqi@0:  * Copyright (c) 1997, 2005, Oracle and/or its affiliates. All rights reserved.
aoqi@0:  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
aoqi@0:  *
aoqi@0:  * This code is free software; you can redistribute it and/or modify it
aoqi@0:  * under the terms of the GNU General Public License version 2 only, as
aoqi@0:  * published by the Free Software Foundation.  Oracle designates this
aoqi@0:  * particular file as subject to the "Classpath" exception as provided
aoqi@0:  * by Oracle in the LICENSE file that accompanied this code.
aoqi@0:  *
aoqi@0:  * This code is distributed in the hope that it will be useful, but WITHOUT
aoqi@0:  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
aoqi@0:  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
aoqi@0:  * version 2 for more details (a copy is included in the LICENSE file that
aoqi@0:  * accompanied this code).
aoqi@0:  *
aoqi@0:  * You should have received a copy of the GNU General Public License version
aoqi@0:  * 2 along with this work; if not, write to the Free Software Foundation,
aoqi@0:  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
aoqi@0:  *
aoqi@0:  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
aoqi@0:  * or visit www.oracle.com if you need additional information or have any
aoqi@0:  * questions.
aoqi@0:  */
aoqi@0: 
aoqi@0: package javax.activation;
aoqi@0: 
aoqi@0: import java.util.Hashtable;
aoqi@0: import java.util.Enumeration;
aoqi@0: import java.util.Locale;
aoqi@0: 
aoqi@0: /**
aoqi@0:  * A parameter list of a MimeType
aoqi@0:  * as defined in RFC 2045 and 2046. The Primary type of the
aoqi@0:  * object must already be stripped off.
aoqi@0:  *
aoqi@0:  * @see javax.activation.MimeType
aoqi@0:  *
aoqi@0:  * @since 1.6
aoqi@0:  */
aoqi@0: public class MimeTypeParameterList {
aoqi@0:     private Hashtable parameters;
aoqi@0: 
aoqi@0:     /**
aoqi@0:      * A string that holds all the special chars.
aoqi@0:      */
aoqi@0:     private static final String TSPECIALS = "()<>@,;:/[]?=\\\"";
aoqi@0: 
aoqi@0: 
aoqi@0:     /**
aoqi@0:      * Default constructor.
aoqi@0:      */
aoqi@0:     public MimeTypeParameterList() {
aoqi@0:         parameters = new Hashtable();
aoqi@0:     }
aoqi@0: 
aoqi@0:     /**
aoqi@0:      * Constructs a new MimeTypeParameterList with the passed in data.
aoqi@0:      *
aoqi@0:      * @param parameterList an RFC 2045, 2046 compliant parameter list.
aoqi@0:      */
aoqi@0:     public MimeTypeParameterList(String parameterList)
aoqi@0:                                         throws MimeTypeParseException {
aoqi@0:         parameters = new Hashtable();
aoqi@0: 
aoqi@0:         //    now parse rawdata
aoqi@0:         parse(parameterList);
aoqi@0:     }
aoqi@0: 
aoqi@0:     /**
aoqi@0:      * A routine for parsing the parameter list out of a String.
aoqi@0:      *
aoqi@0:      * @param parameterList an RFC 2045, 2046 compliant parameter list.
aoqi@0:      */
aoqi@0:     protected void parse(String parameterList) throws MimeTypeParseException {
aoqi@0:         if (parameterList == null)
aoqi@0:             return;
aoqi@0: 
aoqi@0:         int length = parameterList.length();
aoqi@0:         if (length <= 0)
aoqi@0:             return;
aoqi@0: 
aoqi@0:         int i;
aoqi@0:         char c;
aoqi@0:         for (i = skipWhiteSpace(parameterList, 0);
aoqi@0:                 i < length && (c = parameterList.charAt(i)) == ';';
aoqi@0:                 i = skipWhiteSpace(parameterList, i)) {
aoqi@0:             int lastIndex;
aoqi@0:             String name;
aoqi@0:             String value;
aoqi@0: 
aoqi@0:             //    eat the ';'
aoqi@0:             i++;
aoqi@0: 
aoqi@0:             //    now parse the parameter name
aoqi@0: 
aoqi@0:             //    skip whitespace
aoqi@0:             i = skipWhiteSpace(parameterList, i);
aoqi@0: 
aoqi@0:             // tolerate trailing semicolon, even though it violates the spec
aoqi@0:             if (i >= length)
aoqi@0:                 return;
aoqi@0: 
aoqi@0:             //    find the end of the token char run
aoqi@0:             lastIndex = i;
aoqi@0:             while ((i < length) && isTokenChar(parameterList.charAt(i)))
aoqi@0:                 i++;
aoqi@0: 
aoqi@0:             name = parameterList.substring(lastIndex, i).
aoqi@0:                                                 toLowerCase(Locale.ENGLISH);
aoqi@0: 
aoqi@0:             //    now parse the '=' that separates the name from the value
aoqi@0:             i = skipWhiteSpace(parameterList, i);
aoqi@0: 
aoqi@0:             if (i >= length || parameterList.charAt(i) != '=')
aoqi@0:                 throw new MimeTypeParseException(
aoqi@0:                     "Couldn't find the '=' that separates a " +
aoqi@0:                     "parameter name from its value.");
aoqi@0: 
aoqi@0:             //    eat it and parse the parameter value
aoqi@0:             i++;
aoqi@0:             i = skipWhiteSpace(parameterList, i);
aoqi@0: 
aoqi@0:             if (i >= length)
aoqi@0:                 throw new MimeTypeParseException(
aoqi@0:                         "Couldn't find a value for parameter named " + name);
aoqi@0: 
aoqi@0:             //    now find out whether or not we have a quoted value
aoqi@0:             c = parameterList.charAt(i);
aoqi@0:             if (c == '"') {
aoqi@0:                 //    yup it's quoted so eat it and capture the quoted string
aoqi@0:                 i++;
aoqi@0:                 if (i >= length)
aoqi@0:                     throw new MimeTypeParseException(
aoqi@0:                             "Encountered unterminated quoted parameter value.");
aoqi@0: 
aoqi@0:                 lastIndex = i;
aoqi@0: 
aoqi@0:                 //    find the next unescaped quote
aoqi@0:                 while (i < length) {
aoqi@0:                     c = parameterList.charAt(i);
aoqi@0:                     if (c == '"')
aoqi@0:                         break;
aoqi@0:                     if (c == '\\') {
aoqi@0:                         //    found an escape sequence
aoqi@0:                         //    so skip this and the
aoqi@0:                         //    next character
aoqi@0:                         i++;
aoqi@0:                     }
aoqi@0:                     i++;
aoqi@0:                 }
aoqi@0:                 if (c != '"')
aoqi@0:                     throw new MimeTypeParseException(
aoqi@0:                         "Encountered unterminated quoted parameter value.");
aoqi@0: 
aoqi@0:                 value = unquote(parameterList.substring(lastIndex, i));
aoqi@0:                 //    eat the quote
aoqi@0:                 i++;
aoqi@0:             } else if (isTokenChar(c)) {
aoqi@0:                 //    nope it's an ordinary token so it
aoqi@0:                 //    ends with a non-token char
aoqi@0:                 lastIndex = i;
aoqi@0:                 while (i < length && isTokenChar(parameterList.charAt(i)))
aoqi@0:                     i++;
aoqi@0:                 value = parameterList.substring(lastIndex, i);
aoqi@0:             } else {
aoqi@0:                 //    it ain't a value
aoqi@0:                 throw new MimeTypeParseException(
aoqi@0:                         "Unexpected character encountered at index " + i);
aoqi@0:             }
aoqi@0: 
aoqi@0:             //    now put the data into the hashtable
aoqi@0:             parameters.put(name, value);
aoqi@0:         }
aoqi@0:         if (i < length) {
aoqi@0:             throw new MimeTypeParseException(
aoqi@0:                 "More characters encountered in input than expected.");
aoqi@0:         }
aoqi@0:     }
aoqi@0: 
aoqi@0:     /**
aoqi@0:      * Return the number of name-value pairs in this list.
aoqi@0:      *
aoqi@0:      * @return  the number of parameters
aoqi@0:      */
aoqi@0:     public int size() {
aoqi@0:         return parameters.size();
aoqi@0:     }
aoqi@0: 
aoqi@0:     /**
aoqi@0:      * Determine whether or not this list is empty.
aoqi@0:      *
aoqi@0:      * @return  true if there are no parameters
aoqi@0:      */
aoqi@0:     public boolean isEmpty() {
aoqi@0:         return parameters.isEmpty();
aoqi@0:     }
aoqi@0: 
aoqi@0:     /**
aoqi@0:      * Retrieve the value associated with the given name, or null if there
aoqi@0:      * is no current association.
aoqi@0:      *
aoqi@0:      * @param name      the parameter name
aoqi@0:      * @return          the parameter's value
aoqi@0:      */
aoqi@0:     public String get(String name) {
aoqi@0:         return (String)parameters.get(name.trim().toLowerCase(Locale.ENGLISH));
aoqi@0:     }
aoqi@0: 
aoqi@0:     /**
aoqi@0:      * Set the value to be associated with the given name, replacing
aoqi@0:      * any previous association.
aoqi@0:      *
aoqi@0:      * @param name      the parameter name
aoqi@0:      * @param value     the parameter's value
aoqi@0:      */
aoqi@0:     public void set(String name, String value) {
aoqi@0:         parameters.put(name.trim().toLowerCase(Locale.ENGLISH), value);
aoqi@0:     }
aoqi@0: 
aoqi@0:     /**
aoqi@0:      * Remove any value associated with the given name.
aoqi@0:      *
aoqi@0:      * @param name      the parameter name
aoqi@0:      */
aoqi@0:     public void remove(String name) {
aoqi@0:         parameters.remove(name.trim().toLowerCase(Locale.ENGLISH));
aoqi@0:     }
aoqi@0: 
aoqi@0:     /**
aoqi@0:      * Retrieve an enumeration of all the names in this list.
aoqi@0:      *
aoqi@0:      * @return  an enumeration of all parameter names
aoqi@0:      */
aoqi@0:     public Enumeration getNames() {
aoqi@0:         return parameters.keys();
aoqi@0:     }
aoqi@0: 
aoqi@0:     /**
aoqi@0:      * Return a string representation of this object.
aoqi@0:      */
aoqi@0:     public String toString() {
aoqi@0:         StringBuffer buffer = new StringBuffer();
aoqi@0:         buffer.ensureCapacity(parameters.size() * 16);
aoqi@0:                         //    heuristic: 8 characters per field
aoqi@0: 
aoqi@0:         Enumeration keys = parameters.keys();
aoqi@0:         while (keys.hasMoreElements()) {
aoqi@0:             String key = (String)keys.nextElement();
aoqi@0:             buffer.append("; ");
aoqi@0:             buffer.append(key);
aoqi@0:             buffer.append('=');
aoqi@0:             buffer.append(quote((String)parameters.get(key)));
aoqi@0:         }
aoqi@0: 
aoqi@0:         return buffer.toString();
aoqi@0:     }
aoqi@0: 
aoqi@0:     //    below here be scary parsing related things
aoqi@0: 
aoqi@0:     /**
aoqi@0:      * Determine whether or not a given character belongs to a legal token.
aoqi@0:      */
aoqi@0:     private static boolean isTokenChar(char c) {
aoqi@0:         return ((c > 040) && (c < 0177)) && (TSPECIALS.indexOf(c) < 0);
aoqi@0:     }
aoqi@0: 
aoqi@0:     /**
aoqi@0:      * return the index of the first non white space character in
aoqi@0:      * rawdata at or after index i.
aoqi@0:      */
aoqi@0:     private static int skipWhiteSpace(String rawdata, int i) {
aoqi@0:         int length = rawdata.length();
aoqi@0:         while ((i < length) && Character.isWhitespace(rawdata.charAt(i)))
aoqi@0:             i++;
aoqi@0:         return i;
aoqi@0:     }
aoqi@0: 
aoqi@0:     /**
aoqi@0:      * A routine that knows how and when to quote and escape the given value.
aoqi@0:      */
aoqi@0:     private static String quote(String value) {
aoqi@0:         boolean needsQuotes = false;
aoqi@0: 
aoqi@0:         //    check to see if we actually have to quote this thing
aoqi@0:         int length = value.length();
aoqi@0:         for (int i = 0; (i < length) && !needsQuotes; i++) {
aoqi@0:             needsQuotes = !isTokenChar(value.charAt(i));
aoqi@0:         }
aoqi@0: 
aoqi@0:         if (needsQuotes) {
aoqi@0:             StringBuffer buffer = new StringBuffer();
aoqi@0:             buffer.ensureCapacity((int)(length * 1.5));
aoqi@0: 
aoqi@0:             //    add the initial quote
aoqi@0:             buffer.append('"');
aoqi@0: 
aoqi@0:             //    add the properly escaped text
aoqi@0:             for (int i = 0; i < length; ++i) {
aoqi@0:                 char c = value.charAt(i);
aoqi@0:                 if ((c == '\\') || (c == '"'))
aoqi@0:                     buffer.append('\\');
aoqi@0:                 buffer.append(c);
aoqi@0:             }
aoqi@0: 
aoqi@0:             //    add the closing quote
aoqi@0:             buffer.append('"');
aoqi@0: 
aoqi@0:             return buffer.toString();
aoqi@0:         } else {
aoqi@0:             return value;
aoqi@0:         }
aoqi@0:     }
aoqi@0: 
aoqi@0:     /**
aoqi@0:      * A routine that knows how to strip the quotes and
aoqi@0:      * escape sequences from the given value.
aoqi@0:      */
aoqi@0:     private static String unquote(String value) {
aoqi@0:         int valueLength = value.length();
aoqi@0:         StringBuffer buffer = new StringBuffer();
aoqi@0:         buffer.ensureCapacity(valueLength);
aoqi@0: 
aoqi@0:         boolean escaped = false;
aoqi@0:         for (int i = 0; i < valueLength; ++i) {
aoqi@0:             char currentChar = value.charAt(i);
aoqi@0:             if (!escaped && (currentChar != '\\')) {
aoqi@0:                 buffer.append(currentChar);
aoqi@0:             } else if (escaped) {
aoqi@0:                 buffer.append(currentChar);
aoqi@0:                 escaped = false;
aoqi@0:             } else {
aoqi@0:                 escaped = true;
aoqi@0:             }
aoqi@0:         }
aoqi@0: 
aoqi@0:         return buffer.toString();
aoqi@0:     }
aoqi@0: }