org.springframework.amqp.core.Base64UrlNamingStrategy Maven / Gradle / Ivy
/*
* Copyright 2018-2019 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
*
* https://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.UUID;
import org.springframework.util.Assert;
import org.springframework.util.Base64Utils;
/**
* 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.
*
* @author Gary Russell
*
* @since 2.1
*/
public class Base64UrlNamingStrategy implements NamingStrategy {
private static final int SIXTEEN = 16;
/**
* 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[SIXTEEN]);
bb.putLong(uuid.getMostSignificantBits())
.putLong(uuid.getLeastSignificantBits());
// Convert to base64 and remove trailing =
return this.prefix + Base64Utils.encodeToUrlSafeString(bb.array())
.replaceAll("=", "");
}
}