/*
 * Copyright (c) 1997, 2017, Oracle and/or its affiliates. All rights reserved.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation.  Oracle designates this
 * particular file as subject to the "Classpath" exception as provided
 * by Oracle in the LICENSE file that accompanied this code.
 *
 * This code is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
 * or visit www.oracle.com if you need additional information or have any
 * questions.
 */

package javax.activation;

import java.util.Hashtable;
import java.util.Enumeration;
import java.util.Locale;

A parameter list of a MimeType as defined in RFC 2045 and 2046. The Primary type of the object must already be stripped off.
See Also:
  • MimeType
Since:1.6
/** * A parameter list of a MimeType * as defined in RFC 2045 and 2046. The Primary type of the * object must already be stripped off. * * @see javax.activation.MimeType * * @since 1.6 */
public class MimeTypeParameterList { private Hashtable parameters;
A string that holds all the special chars.
/** * A string that holds all the special chars. */
private static final String TSPECIALS = "()<>@,;:/[]?=\\\"";
Default constructor.
/** * Default constructor. */
public MimeTypeParameterList() { parameters = new Hashtable(); }
Constructs a new MimeTypeParameterList with the passed in data.
Params:
  • parameterList – an RFC 2045, 2046 compliant parameter list.
Throws:
/** * Constructs a new MimeTypeParameterList with the passed in data. * * @param parameterList an RFC 2045, 2046 compliant parameter list. * @exception MimeTypeParseException if the MIME type can't be parsed */
public MimeTypeParameterList(String parameterList) throws MimeTypeParseException { parameters = new Hashtable(); // now parse rawdata parse(parameterList); }
A routine for parsing the parameter list out of a String.
Params:
  • parameterList – an RFC 2045, 2046 compliant parameter list.
Throws:
/** * A routine for parsing the parameter list out of a String. * * @param parameterList an RFC 2045, 2046 compliant parameter list. * @exception MimeTypeParseException if the MIME type can't be parsed */
protected void parse(String parameterList) throws MimeTypeParseException { if (parameterList == null) return; int length = parameterList.length(); if (length <= 0) return; int i; char c; for (i = skipWhiteSpace(parameterList, 0); i < length && (c = parameterList.charAt(i)) == ';'; i = skipWhiteSpace(parameterList, i)) { int lastIndex; String name; String value; // eat the ';' i++; // now parse the parameter name // skip whitespace i = skipWhiteSpace(parameterList, i); // tolerate trailing semicolon, even though it violates the spec if (i >= length) return; // find the end of the token char run lastIndex = i; while ((i < length) && isTokenChar(parameterList.charAt(i))) i++; name = parameterList.substring(lastIndex, i). toLowerCase(Locale.ENGLISH); // now parse the '=' that separates the name from the value i = skipWhiteSpace(parameterList, i); if (i >= length || parameterList.charAt(i) != '=') throw new MimeTypeParseException( "Couldn't find the '=' that separates a " + "parameter name from its value."); // eat it and parse the parameter value i++; i = skipWhiteSpace(parameterList, i); if (i >= length) throw new MimeTypeParseException( "Couldn't find a value for parameter named " + name); // now find out whether or not we have a quoted value c = parameterList.charAt(i); if (c == '"') { // yup it's quoted so eat it and capture the quoted string i++; if (i >= length) throw new MimeTypeParseException( "Encountered unterminated quoted parameter value."); lastIndex = i; // find the next unescaped quote while (i < length) { c = parameterList.charAt(i); if (c == '"') break; if (c == '\\') { // found an escape sequence // so skip this and the // next character i++; } i++; } if (c != '"') throw new MimeTypeParseException( "Encountered unterminated quoted parameter value."); value = unquote(parameterList.substring(lastIndex, i)); // eat the quote i++; } else if (isTokenChar(c)) { // nope it's an ordinary token so it // ends with a non-token char lastIndex = i; while (i < length && isTokenChar(parameterList.charAt(i))) i++; value = parameterList.substring(lastIndex, i); } else { // it ain't a value throw new MimeTypeParseException( "Unexpected character encountered at index " + i); } // now put the data into the hashtable parameters.put(name, value); } if (i < length) { throw new MimeTypeParseException( "More characters encountered in input than expected."); } }
Return the number of name-value pairs in this list.
Returns: the number of parameters
/** * Return the number of name-value pairs in this list. * * @return the number of parameters */
public int size() { return parameters.size(); }
Determine whether or not this list is empty.
Returns: true if there are no parameters
/** * Determine whether or not this list is empty. * * @return true if there are no parameters */
public boolean isEmpty() { return parameters.isEmpty(); }
Retrieve the value associated with the given name, or null if there is no current association.
Params:
  • name – the parameter name
Returns: the parameter's value
/** * Retrieve the value associated with the given name, or null if there * is no current association. * * @param name the parameter name * @return the parameter's value */
public String get(String name) { return (String)parameters.get(name.trim().toLowerCase(Locale.ENGLISH)); }
Set the value to be associated with the given name, replacing any previous association.
Params:
  • name – the parameter name
  • value – the parameter's value
/** * Set the value to be associated with the given name, replacing * any previous association. * * @param name the parameter name * @param value the parameter's value */
public void set(String name, String value) { parameters.put(name.trim().toLowerCase(Locale.ENGLISH), value); }
Remove any value associated with the given name.
Params:
  • name – the parameter name
/** * Remove any value associated with the given name. * * @param name the parameter name */
public void remove(String name) { parameters.remove(name.trim().toLowerCase(Locale.ENGLISH)); }
Retrieve an enumeration of all the names in this list.
Returns: an enumeration of all parameter names
/** * Retrieve an enumeration of all the names in this list. * * @return an enumeration of all parameter names */
public Enumeration getNames() { return parameters.keys(); }
Return a string representation of this object.
/** * Return a string representation of this object. */
public String toString() { StringBuffer buffer = new StringBuffer(); buffer.ensureCapacity(parameters.size() * 16); // heuristic: 8 characters per field Enumeration keys = parameters.keys(); while (keys.hasMoreElements()) { String key = (String)keys.nextElement(); buffer.append("; "); buffer.append(key); buffer.append('='); buffer.append(quote((String)parameters.get(key))); } return buffer.toString(); } // below here be scary parsing related things
Determine whether or not a given character belongs to a legal token.
/** * Determine whether or not a given character belongs to a legal token. */
private static boolean isTokenChar(char c) { return ((c > 040) && (c < 0177)) && (TSPECIALS.indexOf(c) < 0); }
return the index of the first non white space character in rawdata at or after index i.
/** * return the index of the first non white space character in * rawdata at or after index i. */
private static int skipWhiteSpace(String rawdata, int i) { int length = rawdata.length(); while ((i < length) && Character.isWhitespace(rawdata.charAt(i))) i++; return i; }
A routine that knows how and when to quote and escape the given value.
/** * A routine that knows how and when to quote and escape the given value. */
private static String quote(String value) { boolean needsQuotes = false; // check to see if we actually have to quote this thing int length = value.length(); for (int i = 0; (i < length) && !needsQuotes; i++) { needsQuotes = !isTokenChar(value.charAt(i)); } if (needsQuotes) { StringBuffer buffer = new StringBuffer(); buffer.ensureCapacity((int)(length * 1.5)); // add the initial quote buffer.append('"'); // add the properly escaped text for (int i = 0; i < length; ++i) { char c = value.charAt(i); if ((c == '\\') || (c == '"')) buffer.append('\\'); buffer.append(c); } // add the closing quote buffer.append('"'); return buffer.toString(); } else { return value; } }
A routine that knows how to strip the quotes and escape sequences from the given value.
/** * A routine that knows how to strip the quotes and * escape sequences from the given value. */
private static String unquote(String value) { int valueLength = value.length(); StringBuffer buffer = new StringBuffer(); buffer.ensureCapacity(valueLength); boolean escaped = false; for (int i = 0; i < valueLength; ++i) { char currentChar = value.charAt(i); if (!escaped && (currentChar != '\\')) { buffer.append(currentChar); } else if (escaped) { buffer.append(currentChar); escaped = false; } else { escaped = true; } } return buffer.toString(); } }