/*
* Copyright 2014 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.websocketx.extensions;
import io.netty.handler.codec.http.
HttpHeaderNames;
import io.netty.handler.codec.http.
HttpHeaderValues;
import io.netty.handler.codec.http.
HttpHeaders;
import java.util.
ArrayList;
import java.util.
Collections;
import java.util.
HashMap;
import java.util.
List;
import java.util.
Map;
import java.util.
Map.
Entry;
import java.util.regex.
Matcher;
import java.util.regex.
Pattern;
public final class
WebSocketExtensionUtil {
private static final
String EXTENSION_SEPARATOR = ",";
private static final
String PARAMETER_SEPARATOR = ";";
private static final char
PARAMETER_EQUAL = '=';
private static final
Pattern PARAMETER =
Pattern.
compile("^([^=]+)(=[\\\"]?([^\\\"]+)[\\\"]?)?$");
static boolean
isWebsocketUpgrade(
HttpHeaders headers) {
return
headers.
containsValue(
HttpHeaderNames.
CONNECTION,
HttpHeaderValues.
UPGRADE, true) &&
headers.
contains(
HttpHeaderNames.
UPGRADE,
HttpHeaderValues.
WEBSOCKET, true);
}
public static
List<
WebSocketExtensionData>
extractExtensions(
String extensionHeader) {
String[]
rawExtensions =
extensionHeader.
split(
EXTENSION_SEPARATOR);
if (
rawExtensions.length > 0) {
List<
WebSocketExtensionData>
extensions = new
ArrayList<
WebSocketExtensionData>(
rawExtensions.length);
for (
String rawExtension :
rawExtensions) {
String[]
extensionParameters =
rawExtension.
split(
PARAMETER_SEPARATOR);
String name =
extensionParameters[0].
trim();
Map<
String,
String>
parameters;
if (
extensionParameters.length > 1) {
parameters = new
HashMap<
String,
String>(
extensionParameters.length - 1);
for (int
i = 1;
i <
extensionParameters.length;
i++) {
String parameter =
extensionParameters[
i].
trim();
Matcher parameterMatcher =
PARAMETER.
matcher(
parameter);
if (
parameterMatcher.
matches() &&
parameterMatcher.
group(1) != null) {
parameters.
put(
parameterMatcher.
group(1),
parameterMatcher.
group(3));
}
}
} else {
parameters =
Collections.
emptyMap();
}
extensions.
add(new
WebSocketExtensionData(
name,
parameters));
}
return
extensions;
} else {
return
Collections.
emptyList();
}
}
static
String appendExtension(
String currentHeaderValue,
String extensionName,
Map<
String,
String>
extensionParameters) {
StringBuilder newHeaderValue = new
StringBuilder(
currentHeaderValue != null ?
currentHeaderValue.
length() :
extensionName.
length() + 1);
if (
currentHeaderValue != null && !
currentHeaderValue.
trim().
isEmpty()) {
newHeaderValue.
append(
currentHeaderValue);
newHeaderValue.
append(
EXTENSION_SEPARATOR);
}
newHeaderValue.
append(
extensionName);
for (
Entry<
String,
String>
extensionParameter :
extensionParameters.
entrySet()) {
newHeaderValue.
append(
PARAMETER_SEPARATOR);
newHeaderValue.
append(
extensionParameter.
getKey());
if (
extensionParameter.
getValue() != null) {
newHeaderValue.
append(
PARAMETER_EQUAL);
newHeaderValue.
append(
extensionParameter.
getValue());
}
}
return
newHeaderValue.
toString();
}
private
WebSocketExtensionUtil() {
// Unused
}
}