Java tutorial
/* * Copyright 2016 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 com.mycompany.springboot.cassandra2; import java.net.InetSocketAddress; import java.net.Socket; import java.util.concurrent.TimeUnit; import org.junit.AssumptionViolatedException; import org.junit.rules.ExternalResource; import org.springframework.data.util.Version; import org.springframework.util.Assert; import com.datastax.driver.core.Cluster; import com.datastax.driver.core.NettyOptions; import com.datastax.driver.core.Session; import io.netty.channel.EventLoopGroup; import java.util.logging.Level; import java.util.logging.Logger; /** * Implementation of an {@link ExternalResource} to verify Apache Cassandra is * running and listening on the given contact point. This rule also creates a * keyspace if it not exists. * * @author Mark Paluch */ public class RequiresCassandraKeyspace extends ExternalResource { private final int timeout = 30; private final String host; private final int port; private final String keyspaceName; private Version requiresVersion; private RequiresCassandraKeyspace(String host, int port, String keyspaceName) { this.host = host; this.port = port; this.keyspaceName = keyspaceName; try { this.before(); } catch (Throwable ex) { Logger.getLogger(RequiresCassandraKeyspace.class.getName()).log(Level.SEVERE, null, ex); } } /** * Require a running Cassandra instance on {@code localhost:9042}. * * @return the {@link RequiresCassandraKeyspace} rule */ public static RequiresCassandraKeyspace onLocalhost() { return new RequiresCassandraKeyspace("localhost", 9042, "test"); } /** * Setup a version requirement. * * @param version must not be {@literal null}. * @return the {@link RequiresCassandraKeyspace} rule */ public RequiresCassandraKeyspace atLeast(Version version) { Assert.notNull(version, "Required version must not be null!"); this.requiresVersion = version; return this; } /* * (non-Javadoc) * @see org.junit.rules.ExternalResource#before() */ @Override protected void before() throws Throwable { try (Socket socket = new Socket()) { socket.setTcpNoDelay(true); socket.setSoLinger(true, 0); socket.connect(new InetSocketAddress(host, port), timeout); } catch (Exception e) { throw new AssumptionViolatedException( String.format("Seems as Cassandra is not running at %s:%s.", host, port), e); } Cluster cluster = Cluster.builder().addContactPoint(host).withPort(port) .withNettyOptions(new NettyOptions() { @Override public void onClusterClose(EventLoopGroup eventLoopGroup) { eventLoopGroup.shutdownGracefully(0, 0, TimeUnit.MILLISECONDS).syncUninterruptibly(); } }).build(); Session session = cluster.newSession(); try { if (requiresVersion != null) { Version cassandraReleaseVersion = CassandraVersion.getReleaseVersion(session); if (cassandraReleaseVersion.isLessThan(requiresVersion)) { throw new AssumptionViolatedException( String.format("Cassandra at %s:%s runs in Version %s but we require at least %s", host, port, cassandraReleaseVersion, requiresVersion)); } } session.execute(String.format( "CREATE KEYSPACE IF NOT EXISTS %s \n" + "WITH REPLICATION = { 'class' : 'SimpleStrategy', 'replication_factor' : 1 };", keyspaceName)); } finally { session.close(); cluster.close(); } } }