/*
* ====================================================================
* 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.apach3.http.contrib.sip;
import java.util.Map;
import java.util.HashMap;
import java.util.Collections;
/**
* Basic implementation of a {@link CompactHeaderMapper}.
* Header names are assumed to be case insensitive.
*
*
*/
public class BasicCompactHeaderMapper implements CompactHeaderMapper {
/**
* The map from compact names to full names.
* Keys are converted to lower case, values may be mixed case.
*/
protected Map<String,String> mapCompactToFull;
/**
* The map from full names to compact names.
* Keys are converted to lower case, values may be mixed case.
*/
protected Map<String,String> mapFullToCompact;
/**
* The default mapper.
* This mapper is initialized with the compact header names defined at
* <a href="http://www.iana.org/assignments/sip-parameters">
* http://www.iana.org/assignments/sip-parameters
* </a>
* on 2008-01-02.
*/
// see below for static initialization
public final static CompactHeaderMapper DEFAULT;
/**
* Creates a new header mapper with an empty mapping.
*/
public BasicCompactHeaderMapper() {
createMaps();
}
/**
* Initializes the two maps.
* The default implementation here creates an empty hash map for
* each attribute that is <code>null</code>.
* Derived implementations may choose to instantiate other
* map implementations, or to populate the maps by default.
* In the latter case, it is the responsibility of the dervied class
* to guarantee consistent mappings in both directions.
*/
protected void createMaps() {
if (mapCompactToFull == null) {
mapCompactToFull = new HashMap<String,String>();
}
if (mapFullToCompact == null) {
mapFullToCompact = new HashMap<String,String>();
}
}
/**
* Adds a header name mapping.
*
* @param compact the compact name of the header
* @param full the full name of the header
*/
public void addMapping(final String compact, final String full) {
if (compact == null) {
throw new IllegalArgumentException
("The compact name must not be null.");
}
if (full == null) {
throw new IllegalArgumentException
("The full name must not be null.");
}
if (compact.length() >= full.length()) {
throw new IllegalArgumentException
("The compact name must be shorter than the full name. " +
compact + " -> " + full);
}
mapCompactToFull.put(compact.toLowerCase(), full);
mapFullToCompact.put(full.toLowerCase(), compact);
}
/**
* Switches this mapper to read-only mode.
* Subsequent invocations of {@link #addMapping addMapping}
* will trigger an exception.
* <br/>
* The implementation here should be called only once.
* It replaces the internal maps with unmodifiable ones.
*/
protected void makeReadOnly() {
mapCompactToFull = Collections.unmodifiableMap(mapCompactToFull);
mapFullToCompact = Collections.unmodifiableMap(mapFullToCompact);
}
// non-javadoc, see interface CompactHeaderMapper
public String getCompactName(final String fullname) {
if (fullname == null) {
throw new IllegalArgumentException
("The full name must not be null.");
}
return mapFullToCompact.get(fullname.toLowerCase());
}
// non-javadoc, see interface CompactHeaderMapper
public String getFullName(final String compactname) {
if (compactname == null) {
throw new IllegalArgumentException
("The compact name must not be null.");
}
return mapCompactToFull.get(compactname.toLowerCase());
}
// non-javadoc, see interface CompactHeaderMapper
public String getAlternateName(final String name) {
if (name == null) {
throw new IllegalArgumentException
("The name must not be null.");
}
final String namelc = name.toLowerCase();
String result = null;
// to minimize lookups, use a heuristic to determine the direction
boolean iscompact = name.length() < 2;
if (iscompact) {
result = mapCompactToFull.get(namelc);
}
if (result == null) {
result = mapFullToCompact.get(namelc);
}
if ((result == null) && !iscompact) {
result = mapCompactToFull.get(namelc);
}
return result;
}
// initializes the default mapper and switches it to read-only mode
static {
BasicCompactHeaderMapper chm = new BasicCompactHeaderMapper();
chm.addMapping("a", "Accept-Contact");
chm.addMapping("u", "Allow-Events");
chm.addMapping("i", "Call-ID");
chm.addMapping("m", "Contact");
chm.addMapping("e", "Content-Encoding");
chm.addMapping("l", "Content-Length");
chm.addMapping("c", "Content-Type");
chm.addMapping("o", "Event");
chm.addMapping("f", "From");
chm.addMapping("y", "Identity");
chm.addMapping("n", "Identity-Info");
chm.addMapping("r", "Refer-To");
chm.addMapping("b", "Referred-By");
chm.addMapping("j", "Reject-Contact");
chm.addMapping("d", "Request-Disposition");
chm.addMapping("x", "Session-Expires");
chm.addMapping("s", "Subject");
chm.addMapping("k", "Supported");
chm.addMapping("t", "To");
chm.addMapping("v", "Via");
chm.makeReadOnly();
DEFAULT = chm;
}
}