netty5/codec-http/src/main/java/io/netty/handler/codec/http/QueryStringEncoder.java
Nikolay Fedorovskikh d672a5a483 Optimizations in QueryStringEncoder
Motivation:

A life cycle of QueryStringEncoder is simple: create, append params, convert to String. Current realization collect params in the list, and calculate an URI string in `toString` method. We can simplify this: don't store params to the list, and immediately append parameters to the `StringBuilder`.

Modifications:

- Remove list for params and remove a tuple class `Param`.
- Use one common `StringBuilder` and append parameters into it.
- Resolve `TODO` in the `encodeParam` method.

Result:

Less allocations (no `ArrayList`, no `Param` tuples). Second `toString` call is faster.
2017-06-23 14:03:32 -07:00

123 lines
3.8 KiB
Java

/*
* 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 io.netty.util.internal.ObjectUtil;
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;
/**
* 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 String charsetName;
private final StringBuilder uriBuilder;
private boolean hasParams;
/**
* 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) {
uriBuilder = new StringBuilder(uri);
charsetName = charset.name();
}
/**
* Adds a parameter with the specified name and value to this encoder.
*/
public void addParam(String name, String value) {
ObjectUtil.checkNotNull(name, "name");
if (hasParams) {
uriBuilder.append('&');
} else {
uriBuilder.append('?');
hasParams = true;
}
appendComponent(name, charsetName, uriBuilder);
if (value != null) {
uriBuilder.append('=');
appendComponent(value, charsetName, uriBuilder);
}
}
/**
* 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)} method.
*/
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)} method.
*/
@Override
public String toString() {
return uriBuilder.toString();
}
private static void appendComponent(String s, String charset, StringBuilder sb) {
try {
s = URLEncoder.encode(s, charset);
} catch (UnsupportedEncodingException ignored) {
throw new UnsupportedCharsetException(charset);
}
// replace all '+' with "%20"
int idx = s.indexOf('+');
if (idx == -1) {
sb.append(s);
return;
}
sb.append(s, 0, idx).append("%20");
int size = s.length();
idx++;
for (; idx < size; idx++) {
char c = s.charAt(idx);
if (c != '+') {
sb.append(c);
} else {
sb.append("%20");
}
}
}
}