org.springframework.amqp.core.AnonymousQueue Maven / Gradle / Ivy
/*
* Copyright 2002-2017 the original author or authors.
*
* 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 org.springframework.amqp.core;
import java.nio.ByteBuffer;
import java.util.Map;
import java.util.UUID;
import org.springframework.util.Assert;
import org.springframework.util.Base64Utils;
/**
* Represents an anonymous, non-durable, exclusive, auto-delete queue. The name has the
* form 'spring.gen-<base64UUID>' by default, but it can be modified by providing a
* {@link NamingStrategy}. Two naming strategies {@link Base64UrlNamingStrategy} and
* {@link UUIDNamingStrategy} are provided but you can implement your own. Names should be
* unique.
* @author Dave Syer
* @author Gary Russell
*
*/
public class AnonymousQueue extends Queue {
/**
* Construct a queue with a Base64-based name.
*/
public AnonymousQueue() {
this((Map) null);
}
/**
* Construct a queue with a Base64-based name with the supplied arguments.
* @param arguments the arguments.
*/
public AnonymousQueue(Map arguments) {
this(Base64UrlNamingStrategy.DEFAULT, arguments);
}
/**
* Construct a queue with a name provided by the supplied naming strategy.
* @param namingStrategy the naming strategy.
* @since 1.5.3
*/
public AnonymousQueue(NamingStrategy namingStrategy) {
this(namingStrategy, null);
}
/**
* Construct a queue with a name provided by the supplied naming strategy with the
* supplied arguments.
* @param namingStrategy the naming strategy.
* @param arguments the arguments.
* @since 1.5.3
*/
public AnonymousQueue(NamingStrategy namingStrategy, Map arguments) {
super(namingStrategy.generateName(), false, true, true, arguments);
}
/**
* A strategy to name anonymous queues.
* @since 1.5.3
*
*/
@FunctionalInterface
public interface NamingStrategy {
String generateName();
}
/**
* Generates names with the form {@code } where
* 'prefix' is 'spring.gen-' by default
* (e.g. spring.gen-eIwaZAYgQv6LvwaDCfVTNQ);
* the 'base64url' String is generated from a UUID. The base64 alphabet
* is the "URL and Filename Safe Alphabet"; see RFC-4648. Trailing padding
* characters (@code =) are removed.
* @since 1.5.3
*/
public static class Base64UrlNamingStrategy implements NamingStrategy {
/**
* The default instance - using {@code spring.gen-} as the prefix.
*/
public static final Base64UrlNamingStrategy DEFAULT = new Base64UrlNamingStrategy();
private final String prefix;
/**
* Construct an instance using the default prefix {@code spring.gen-}.
*/
public Base64UrlNamingStrategy() {
this("spring.gen-");
}
/**
* Construct an instance using the supplied prefix.
* @param prefix The prefix.
*/
public Base64UrlNamingStrategy(String prefix) {
Assert.notNull(prefix, "'prefix' cannot be null; use an empty String ");
this.prefix = prefix;
}
@Override
public String generateName() {
UUID uuid = UUID.randomUUID();
ByteBuffer bb = ByteBuffer.wrap(new byte[16]);
bb.putLong(uuid.getMostSignificantBits())
.putLong(uuid.getLeastSignificantBits());
// Convert to base64 and remove trailing =
return this.prefix + Base64Utils.encodeToUrlSafeString(bb.array())
.replaceAll("=", "");
}
}
/**
* Generates names using {@link UUID#randomUUID()}.
* (e.g. "f20c818a-006b-4416-bf91-643590fedb0e").
* @author Gary Russell
* @since 5.0
*/
public static class UUIDNamingStrategy implements NamingStrategy {
/**
* The default instance.
*/
public static final UUIDNamingStrategy DEFAULT = new UUIDNamingStrategy();
@Override
public String generateName() {
return UUID.randomUUID().toString();
}
}
}