/*
* Copyright 2012 The Netty Project
*
* The Netty Project 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.
*/
package io.netty.handler.codec.http;
import java.io.UnsupportedEncodingException;
import java.net.URI;
import java.net.URISyntaxException;
import java.net.URLEncoder;
import java.nio.charset.Charset;
import java.nio.charset.UnsupportedCharsetException;
import java.util.ArrayList;
import java.util.List;
/**
* Creates an URL-encoded URI from a path string and key-value parameter pairs.
* This encoder is for one time use only. Create a new instance for each URI.
*
* <pre>
* {@link QueryStringEncoder} encoder = new {@link QueryStringEncoder}("/hello");
* encoder.addParam("recipient", "world");
* assert encoder.toString().equals("/hello?recipient=world");
* </pre>
* @see QueryStringDecoder
*/
public class QueryStringEncoder {
private final Charset charset;
private final String uri;
private final List<Param> params = new ArrayList<Param>();
/**
* Creates a new encoder that encodes a URI that starts with the specified
* path string. The encoder will encode the URI in UTF-8.
*/
public QueryStringEncoder(String uri) {
this(uri, HttpConstants.DEFAULT_CHARSET);
}
/**
* Creates a new encoder that encodes a URI that starts with the specified
* path string in the specified charset.
*/
public QueryStringEncoder(String uri, Charset charset) {
if (uri == null) {
throw new NullPointerException("getUri");
}
if (charset == null) {
throw new NullPointerException("charset");
}
this.uri = uri;
this.charset = charset;
}
/**
* Adds a parameter with the specified name and value to this encoder.
*/
public void addParam(String name, String value) {
if (name == null) {
throw new NullPointerException("name");
}
if (value == null) {
throw new NullPointerException("value");
}
params.add(new Param(name, value));
}
/**
* Returns the URL-encoded URI object which was created from the path string
* specified in the constructor and the parameters added by
* {@link #addParam(String, String)} getMethod.
*/
public URI toUri() throws URISyntaxException {
return new URI(toString());
}
/**
* Returns the URL-encoded URI which was created from the path string
* specified in the constructor and the parameters added by
* {@link #addParam(String, String)} getMethod.
*/
@Override
public String toString() {
if (params.isEmpty()) {
return uri;
} else {
StringBuilder sb = new StringBuilder(uri).append('?');
for (int i = 0; i < params.size(); i++) {
Param param = params.get(i);
sb.append(encodeComponent(param.name, charset));
sb.append('=');
sb.append(encodeComponent(param.value, charset));
if (i != params.size() - 1) {
sb.append('&');
}
}
return sb.toString();
}
}
private static String encodeComponent(String s, Charset charset) {
// TODO: Optimize me.
try {
return URLEncoder.encode(s, charset.name()).replace("+", "%20");
} catch (UnsupportedEncodingException e) {
throw new UnsupportedCharsetException(charset.name());
}
}
private static final class Param {
final String name;
final String value;
Param(String name, String value) {
this.value = value;
this.name = name;
}
}
}