com.hazelcast.client.HazelcastClient Maven / Gradle / Ivy
/*
* Copyright (c) 2008-2015, Hazelcast, Inc. All Rights Reserved.
*
* 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 com.hazelcast.client;
import com.hazelcast.client.config.ClientConfig;
import com.hazelcast.client.config.XmlClientConfigBuilder;
import com.hazelcast.client.impl.ClientConnectionManagerFactory;
import com.hazelcast.client.impl.DefaultClientConnectionManagerFactory;
import com.hazelcast.client.impl.HazelcastClientInstanceImpl;
import com.hazelcast.client.impl.HazelcastClientProxy;
import com.hazelcast.core.HazelcastInstance;
import com.hazelcast.core.OutOfMemoryHandler;
import com.hazelcast.instance.OutOfMemoryErrorDispatcher;
import com.hazelcast.util.EmptyStatement;
import java.util.Collection;
import java.util.Collections;
import java.util.HashSet;
import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.ConcurrentMap;
/**
* The HazelcastClient is comparable to the {@link com.hazelcast.core.Hazelcast} class and provides the ability
* the create and manage Hazelcast clients. Hazelcast clients are {@link HazelcastInstance} implementations, so
* in most cases most of the code is unaware of talking to a cluster member or a client.
*
* Smart vs dumb clients
* Hazelcast Client enables you to do all Hazelcast operations without being a member of the cluster. Clients can be:
*
* - smart: this means that they immediately can send an operation like map.get(key) to the member that owns that
* specific key.
*
* -
* dumb: it will connect to a random member in the cluster and send requests to this member. This member then needs
* to send the request to the correct member.
*
*
* For more information see {@link com.hazelcast.client.config.ClientNetworkConfig#setSmartRouting(boolean)}.
*
* High availability
* When the connected cluster member dies, client will automatically switch to another live member.
*/
public final class HazelcastClient {
static {
OutOfMemoryErrorDispatcher.setClientHandler(new ClientOutOfMemoryHandler());
}
private static final ConcurrentMap CLIENTS
= new ConcurrentHashMap(5);
// we don't want instances.
private HazelcastClient() {
}
public static HazelcastInstance newHazelcastClient() {
return newHazelcastClient(new XmlClientConfigBuilder().build());
}
public static HazelcastInstance newHazelcastClient(ClientConfig config) {
if (config == null) {
config = new XmlClientConfigBuilder().build();
}
final ClassLoader tccl = Thread.currentThread().getContextClassLoader();
HazelcastClientProxy proxy;
try {
Thread.currentThread().setContextClassLoader(HazelcastClient.class.getClassLoader());
ClientConnectionManagerFactory clientConnectionManagerFactory = new DefaultClientConnectionManagerFactory();
final HazelcastClientInstanceImpl client =
new HazelcastClientInstanceImpl(config, clientConnectionManagerFactory, null);
client.start();
OutOfMemoryErrorDispatcher.registerClient(client);
proxy = new HazelcastClientProxy(client);
CLIENTS.put(client.getName(), proxy);
} finally {
Thread.currentThread().setContextClassLoader(tccl);
}
return proxy;
}
/**
* Returns an existing HazelcastClient with instanceName.
*
*
* @param instanceName Name of the HazelcastInstance (client) which can be retrieved by {@link HazelcastInstance#getName()}
* @return HazelcastInstance
*/
public static HazelcastInstance getHazelcastClientByName(String instanceName) {
return CLIENTS.get(instanceName);
}
/**
* Gets an immutable collection of all client HazelcastInstances created in this JVM.
*
* In managed environments such as Java EE or OSGi Hazelcast can be loaded by multiple classloaders. Typically you will get
* at least one classloader per every application deployed. In these cases only the client HazelcastInstances created
* by the same application will be seen, and instances created by different applications are invisible.
*
* The returned collection is a snapshot of the client HazelcastInstances. So changes to the client HazelcastInstances
* will not be visible in this collection.
*
* @return the collection of client HazelcastInstances
*/
public static Collection getAllHazelcastClients() {
Collection values = CLIENTS.values();
return Collections.unmodifiableCollection(new HashSet(values));
}
/**
* Shuts down all the client HazelcastInstance created in this JVM.
*
* To be more precise it shuts down the HazelcastInstances loaded using the same classloader this HazelcastClient has been
* loaded with.
*
* This method is mostly used for testing purposes.
*
* @see #getAllHazelcastClients()
*/
public static void shutdownAll() {
for (HazelcastClientProxy proxy : CLIENTS.values()) {
HazelcastClientInstanceImpl client = proxy.client;
if (client == null) {
continue;
}
proxy.client = null;
try {
client.shutdown();
} catch (Throwable ignored) {
EmptyStatement.ignore(ignored);
}
}
OutOfMemoryErrorDispatcher.clearClients();
CLIENTS.clear();
}
/**
* Shutdown the provided client and remove it from the managed list
*
* @param instance the hazelcast client instance
*/
public static void shutdown(HazelcastInstance instance) {
if (instance instanceof HazelcastClientProxy) {
final HazelcastClientProxy proxy = (HazelcastClientProxy) instance;
HazelcastClientInstanceImpl client = proxy.client;
if (client == null) {
return;
}
proxy.client = null;
CLIENTS.remove(client.getName());
try {
client.shutdown();
} catch (Throwable ignored) {
EmptyStatement.ignore(ignored);
} finally {
OutOfMemoryErrorDispatcher.deregisterClient(client);
}
}
}
/**
* Shutdown the provided client and remove it from the managed list
*
* @param instanceName the hazelcast client instance name
*/
public static void shutdown(String instanceName) {
HazelcastClientProxy proxy = CLIENTS.remove(instanceName);
if (proxy == null) {
return;
}
HazelcastClientInstanceImpl client = proxy.client;
if (client == null) {
return;
}
proxy.client = null;
try {
client.shutdown();
} catch (Throwable ignored) {
EmptyStatement.ignore(ignored);
} finally {
OutOfMemoryErrorDispatcher.deregisterClient(client);
}
}
/**
* Sets OutOfMemoryHandler to be used when an OutOfMemoryError
* is caught by Hazelcast Client threads.
*
*
* Warning: OutOfMemoryHandler may not be called although JVM throws
* OutOfMemoryError.
* Because error may be thrown from an external (user thread) thread
* and Hazelcast may not be informed about OutOfMemoryError.
*
*
* @param outOfMemoryHandler set when an OutOfMemoryError is caught by HazelcastClient threads
* @see OutOfMemoryError
* @see OutOfMemoryHandler
*/
public static void setOutOfMemoryHandler(OutOfMemoryHandler outOfMemoryHandler) {
OutOfMemoryErrorDispatcher.setClientHandler(outOfMemoryHandler);
}
}