package com.datasift.dropwizard.zookeeper;
import com.datasift.dropwizard.zookeeper.config.ZooKeeperConfiguration;
import com.datasift.dropwizard.zookeeper.health.ZooKeeperHealthCheck;
import com.yammer.dropwizard.config.Environment;
import org.apache.zookeeper.Watcher;
import org.apache.zookeeper.ZooKeeper;
import java.io.IOException;
/**
* A Factory for creating configured and managed {@link ZooKeeper} client instances.
* <p/>
* A {@link ZooKeeperHealthCheck} will be registered for each {@link ZooKeeper} client isntance that
* checks for the existence of the configured {@link ZooKeeperConfiguration#namespace namespace}.
*
* @see ZooKeeperConfiguration
* @see ZooKeeperHealthCheck
* @see ManagedZooKeeper
*/
public class ZooKeeperFactory {
private static final String DEFAULT_NAME = "default";
private final Environment environment;
/**
* Creates a new {@link ZooKeeperFactory} instance for the specified {@link Environment}.
*
* @param environment the environment to build {@link ZooKeeper} instances for.
*/
public ZooKeeperFactory(final Environment environment) {
this.environment = environment;
}
/**
* Builds a default {@link ZooKeeper} instance from the given {@link ZooKeeperConfiguration}.
* <p/>
* No {@link Watcher} will be configured for the built {@link ZooKeeper} instance. If you wish
* to watch all events on the {@link ZooKeeper} client, use
* {@link #build(ZooKeeperConfiguration, Watcher)}.
*
* @param configuration the configuration to configure the {@link ZooKeeper} instance with.
*
* @return a {@link ZooKeeper} client, managed and configured according to the {@code
* configuration}.
*
* @throws IOException if there is a network failure.
*/
public ZooKeeper build(final ZooKeeperConfiguration configuration) throws IOException {
return build(configuration, null, DEFAULT_NAME);
}
/**
* Builds a default {@link ZooKeeper} instance from the given {@link ZooKeeperConfiguration}.
* <p/>
* The given {@link Watcher} will be assigned to watch for all events on the {@link ZooKeeper}
* client instance. If you wish to ignore events, use {@link #build(ZooKeeperConfiguration)}.
*
* @param configuration the configuration to configure the {@link ZooKeeper} instance with.
* @param watcher the watcher to handle all events that occur on the {@link ZooKeeper} client.
*
* @return a {@link ZooKeeper} client, managed and configured according to the {@code
* configuration}.
*
* @throws IOException if there is a network failure.
*/
public ZooKeeper build(final ZooKeeperConfiguration configuration, final Watcher watcher)
throws IOException {
return build(configuration, watcher, DEFAULT_NAME);
}
/**
* Builds a named {@link ZooKeeper} instance from the given {@link ZooKeeperConfiguration}.
* <p/>
* No {@link Watcher} will be configured for the built {@link ZooKeeper} instance. If you wish
* to watch all events on the {@link ZooKeeper} client, use {@link
* #build(ZooKeeperConfiguration, Watcher, String)}.
*
* @param configuration the configuration to configure the {@link ZooKeeper} instance with.
* @param name the name for this {@link ZooKeeper instance}.
*
* @return a {@link ZooKeeper} client, managed and configured according to the {@code
* configuration}.
*
* @throws IOException if there is a network failure.
*/
public ZooKeeper build(final ZooKeeperConfiguration configuration, final String name)
throws IOException {
return build(configuration, null, name);
}
/**
* Builds a named {@link ZooKeeper} instance from the given {@link ZooKeeperConfiguration}.
* <p/>
* The given {@link Watcher} will be assigned to watch for all events on the {@link ZooKeeper}
* client instance. If you wish to ignore events, use {@link
* #build(ZooKeeperConfiguration, String)}.
*
* @param configuration the configuration to configure the {@link ZooKeeper} instance with.
* @param watcher the watcher to handle all events that occur on the {@link ZooKeeper} client.
* @param name the name for this {@link ZooKeeper instance}.
*
* @return a {@link ZooKeeper} client, managed and configured according to the {@code
* configuration}.
*
* @throws IOException if there is a network failure.
*/
public ZooKeeper build(final ZooKeeperConfiguration configuration,
final Watcher watcher,
final String name) throws IOException {
final String quorumSpec = configuration.getQuorumSpec();
final String namespace = configuration.getNamespace();
final ZooKeeper client = new ZooKeeper(
quorumSpec + namespace,
(int) configuration.getSessionTimeout().toMilliseconds(),
watcher,
configuration.canBeReadOnly());
final ZooKeeperConfiguration.Auth auth = configuration.getAuth();
if (auth != null) {
client.addAuthInfo(auth.getScheme(), auth.getId());
}
environment.addHealthCheck(new ZooKeeperHealthCheck(client, quorumSpec, namespace, name));
environment.manage(new ManagedZooKeeper(client));
return client;
}
}