/*
* $HeadURL: http://svn.apache.org/repos/asf/httpcomponents/httpclient/trunk/module-client/src/main/java/org/apache/http/client/utils/URLEncodedUtils.java $
* $Revision: 655107 $
* $Date: 2008-05-10 08:20:42 -0700 (Sat, 10 May 2008) $
* ====================================================================
* 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.apache.http.client.utils;
import java.io.IOException;
import java.io.UnsupportedEncodingException;
import java.net.URI;
import java.net.URLDecoder;
import java.net.URLEncoder;
import java.util.ArrayList;
import java.util.Collections;
import java.util.List;
import java.util.Scanner;
import org.apache.http.Header;
import org.apache.http.HttpEntity;
import org.apache.http.NameValuePair;
import org.apache.http.message.BasicNameValuePair;
import org.apache.http.protocol.HTTP;
import org.apache.http.util.EntityUtils;
/**
* A collection of utilities for encoding URLs.
*/
public class URLEncodedUtils {
public static final String CONTENT_TYPE = "application/x-www-form-urlencoded";
private static final String PARAMETER_SEPARATOR = "&";
private static final String NAME_VALUE_SEPARATOR = "=";
/**
* Returns a list of {@link NameValuePair NameValuePairs} as built from the
* URI's query portion. For example, a URI of
* http://example.org/path/to/file?a=1&b=2&c=3 would return a list of three
* NameValuePairs, one for a=1, one for b=2, and one for c=3.
* <p>
* This is typically useful while parsing an HTTP PUT.
*
* @param uri
* uri to parse
* @param encoding
* encoding to use while parsing the query
*/
public static List <NameValuePair> parse (final URI uri, final String encoding) {
List <NameValuePair> result = Collections.emptyList();
final String query = uri.getRawQuery();
if (query != null && query.length() > 0) {
result = new ArrayList <NameValuePair>();
parse(result, new Scanner(query), encoding);
}
return result;
}
/**
* Returns a list of {@link NameValuePair NameValuePairs} as parsed from an
* {@link HttpEntity}. The encoding is taken from the entity's
* Content-Encoding header.
* <p>
* This is typically used while parsing an HTTP POST.
*
* @param entity
* The entity to parse
* @throws IOException
* If there was an exception getting the entity's data.
*/
public static List <NameValuePair> parse (
final HttpEntity entity) throws IOException {
List <NameValuePair> result = Collections.emptyList();
if (isEncoded(entity)) {
final String content = EntityUtils.toString(entity);
final Header encoding = entity.getContentEncoding();
if (content != null && content.length() > 0) {
result = new ArrayList <NameValuePair>();
parse(result, new Scanner(content),
encoding != null ? encoding.getValue() : null);
}
}
return result;
}
/**
* Returns true if the entity's Content-Type header is
* <code>application/x-www-form-urlencoded</code>.
*/
public static boolean isEncoded (final HttpEntity entity) {
final Header contentType = entity.getContentType();
return (contentType != null && contentType.getValue().equalsIgnoreCase(CONTENT_TYPE));
}
/**
* Adds all parameters within the Scanner to the list of
* <code>parameters</code>, as encoded by <code>encoding</code>. For
* example, a scanner containing the string <code>a=1&b=2&c=3</code> would
* add the {@link NameValuePair NameValuePairs} a=1, b=2, and c=3 to the
* list of parameters.
*
* @param parameters
* List to add parameters to.
* @param scanner
* Input that contains the parameters to parse.
* @param encoding
* Encoding to use when decoding the parameters.
*/
public static void parse (
final List <NameValuePair> parameters,
final Scanner scanner,
final String encoding) {
scanner.useDelimiter(PARAMETER_SEPARATOR);
while (scanner.hasNext()) {
final String[] nameValue = scanner.next().split(NAME_VALUE_SEPARATOR);
if (nameValue.length == 0 || nameValue.length > 2)
throw new IllegalArgumentException("bad parameter");
final String name = decode(nameValue[0], encoding);
String value = null;
if (nameValue.length == 2)
value = decode(nameValue[1], encoding);
parameters.add(new BasicNameValuePair(name, value));
}
}
/**
* Returns a String that is suitable for use as an <code>application/x-www-form-urlencoded</code>
* list of parameters in an HTTP PUT or HTTP POST.
*
* @param parameters The parameters to include.
* @param encoding The encoding to use.
*/
public static String format (
final List <? extends NameValuePair> parameters,
final String encoding) {
final StringBuilder result = new StringBuilder();
for (final NameValuePair parameter : parameters) {
final String encodedName = encode(parameter.getName(), encoding);
final String value = parameter.getValue();
final String encodedValue = value != null ? encode(value, encoding) : "";
if (result.length() > 0)
result.append(PARAMETER_SEPARATOR);
result.append(encodedName);
result.append(NAME_VALUE_SEPARATOR);
result.append(encodedValue);
}
return result.toString();
}
private static String decode (final String content, final String encoding) {
try {
return URLDecoder.decode(content,
encoding != null ? encoding : HTTP.DEFAULT_CONTENT_CHARSET);
} catch (UnsupportedEncodingException problem) {
throw new IllegalArgumentException(problem);
}
}
private static String encode (final String content, final String encoding) {
try {
return URLEncoder.encode(content,
encoding != null ? encoding : HTTP.DEFAULT_CONTENT_CHARSET);
} catch (UnsupportedEncodingException problem) {
throw new IllegalArgumentException(problem);
}
}
}