/*
* JBoss, Home of Professional Open Source
*
* Copyright 2009, Red Hat Middleware LLC, and individual contributors
* by the @author tags. See the COPYRIGHT.txt in the distribution for a
* full listing of individual contributors.
*
* This is free software; you can redistribute it and/or modify it
* under the terms of the GNU Lesser General Public License as
* published by the Free Software Foundation; either version 2.1 of
* the License, or (at your option) any later version.
*
* This software 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
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this software; if not, write to the Free
* Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
* 02110-1301 USA, or see the FSF site: http://www.fsf.org.
*/
package org.jboss.netty.handler.codec.http;
import java.io.UnsupportedEncodingException;
import java.net.URI;
import java.net.URLDecoder;
import java.nio.charset.UnsupportedCharsetException;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
/**
* Splits an HTTP query string into a path string and key-value parameter pairs.
* This decoder is for one time use only. Create a new instance for each URI:
* <pre>
* QueryStringDecoder decoder = new QueryStringDecoder("/hello?recipient=world");
* assert decoder.getPath().equals("/hello");
* assert decoder.getParameters().get("recipient").equals("world");
* </pre>
*
* @author The Netty Project (netty-dev@lists.jboss.org)
* @author Andy Taylor (andy.taylor@jboss.org)
* @author Trustin Lee (tlee@redhat.com)
* @version $Rev: 1586 $, $Date: 2009-07-20 12:37:35 +0900 (Mon, 20 Jul 2009) $
*
* @see QueryStringEncoder
*
* @apiviz.stereotype utility
* @apiviz.has org.jboss.netty.handler.codec.http.HttpRequest oneway - - decodes
*/
public class QueryStringDecoder {
private static final Pattern PARAM_PATTERN = Pattern.compile("([^=]*)=([^&]*)&*");
private final String charset;
private final String uri;
private String path;
private final Map<String, List<String>> params = new HashMap<String, List<String>>();
/**
* Creates a new decoder that decodes the specified URI. The decoder will
* assume that the query string is encoded in UTF-8.
*/
public QueryStringDecoder(String uri) {
this(uri, HttpCodecUtil.DEFAULT_CHARSET);
}
/**
* Creates a new decoder that decodes the specified URI encoded in the
* specified charset.
*/
public QueryStringDecoder(String uri, String charset) {
if (uri == null) {
throw new NullPointerException("uri");
}
if (charset == null) {
throw new NullPointerException("charset");
}
this.uri = uri;
this.charset = charset;
}
/**
* Creates a new decoder that decodes the specified URI. The decoder will
* assume that the query string is encoded in UTF-8.
*/
public QueryStringDecoder(URI uri) {
this(uri, HttpCodecUtil.DEFAULT_CHARSET);
}
/**
* Creates a new decoder that decodes the specified URI encoded in the
* specified charset.
*/
public QueryStringDecoder(URI uri, String charset){
if (uri == null) {
throw new NullPointerException("uri");
}
if (charset == null) {
throw new NullPointerException("charset");
}
this.uri = uri.toASCIIString();
this.charset = charset;
}
/**
* Returns the decoded path string of the URI.
*/
public String getPath() {
//decode lazily
if(path == null) {
if(uri.contains("?")) {
decode();
}
else {
path = uri;
}
}
return path;
}
/**
* Returns the decoded key-value parameter pairs of the URI.
*/
public Map<String, List<String>> getParameters() {
if(path == null){
if(uri.contains("?")) {
decode();
}
else {
path = uri;
}
}
return params;
}
private void decode() {
int pathEndPos = uri.indexOf('?');
if (pathEndPos < 0) {
path = uri;
} else {
path = uri.substring(0, pathEndPos);
decodeParams(uri.substring(pathEndPos + 1));
}
}
private void decodeParams(String s) {
Matcher m = PARAM_PATTERN.matcher(s);
int pos = 0;
while (m.find(pos)) {
pos = m.end();
String key = decodeComponent(m.group(1), charset);
String value = decodeComponent(m.group(2), charset);
List<String> values = params.get(key);
if(values == null) {
values = new ArrayList<String>();
params.put(key,values);
}
values.add(value);
}
}
private static String decodeComponent(String s, String charset) {
if (s == null) {
return "";
}
try {
return URLDecoder.decode(s, charset);
} catch (UnsupportedEncodingException e) {
throw new UnsupportedCharsetException(charset);
}
}
}