/*
* JBoss, Home of Professional Open Source.
* Copyright 2014 Red Hat, Inc., and individual contributors
* as indicated by the @author tags.
*
* Licensed 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.undertow.websockets;
import java.util.
ArrayList;
import java.util.
Collections;
import java.util.
Iterator;
import java.util.
List;
/**
* @author Stuart Douglas
*/
public class
WebSocketExtension {
private final
String name;
private final
List<
Parameter>
parameters;
public
WebSocketExtension(
String name) {
this.
name =
name;
this.
parameters = new
ArrayList<>();
}
public
WebSocketExtension(
String name,
List<
Parameter>
parameters) {
this.
name =
name;
this.
parameters =
Collections.
unmodifiableList(new
ArrayList<>(
parameters));
}
public
String getName() {
return
name;
}
public
List<
Parameter>
getParameters() {
return
parameters;
}
public static final class
Parameter {
private final
String name;
private final
String value;
public
Parameter(
String name,
String value) {
this.
name =
name;
this.
value =
value;
}
public
String getName() {
return
name;
}
public
String getValue() {
return
value;
}
@
Override
public
String toString() {
return "{'" +
name + '\'' +
": '" +
value + '\'' +
'}';
}
}
@
Override
public
String toString() {
return "WebSocketExtension{" +
"name='" +
name + '\'' +
", parameters=" +
parameters +
'}';
}
public static
List<
WebSocketExtension>
parse(final
String extensionHeader) {
if(
extensionHeader == null ||
extensionHeader.
isEmpty()) {
return
Collections.
emptyList();
}
List<
WebSocketExtension>
extensions = new
ArrayList<>();
//TODO: more efficient parsing algorithm
String[]
parts =
extensionHeader.
split(",");
for (
String part :
parts) {
String[]
items =
part.
split(";");
if (
items.length > 0) {
final
List<
Parameter>
params = new
ArrayList<>(
items.length - 1);
String name =
items[0].
trim();
for (int
i = 1;
i <
items.length; ++
i) {
/*
Extensions can have parameters without values
*/
if (
items[
i].
contains("=")) {
String[]
param =
items[
i].
split("=");
if (
param.length == 2) {
params.
add(new
Parameter(
param[0].
trim(),
param[1].
trim()));
}
} else {
params.
add(new
Parameter(
items[
i].
trim(), null));
}
}
extensions.
add(new
WebSocketExtension(
name,
params));
}
}
return
extensions;
}
/**
* Compose a String from a list of extensions to be used in the response of a protocol negotiation.
*
* @see io.undertow.util.Headers
*
* @param extensions list of {@link WebSocketExtension}
* @return a string representation of the extensions
*/
public static
String toExtensionHeader(final
List<
WebSocketExtension>
extensions) {
StringBuilder extensionsHeader = new
StringBuilder();
if (
extensions != null &&
extensions.
size() > 0) {
Iterator<
WebSocketExtension>
it =
extensions.
iterator();
while (
it.
hasNext()) {
WebSocketExtension extension =
it.
next();
extensionsHeader.
append(
extension.
getName());
for (
Parameter param :
extension.
getParameters()) {
extensionsHeader.
append("; ").
append(
param.
getName());
if (
param.
getValue() != null &&
param.
getValue().
length() > 0) {
extensionsHeader.
append("=").
append(
param.
getValue());
}
}
if (
it.
hasNext()) {
extensionsHeader.
append(", ");
}
}
}
return
extensionsHeader.
toString();
}
}