/* * Copyright (C) 2012-2015 DataStax Inc. * * 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.datastax.driver.examples.basic; import com.datastax.driver.core.*; /** * Gathers information about a Cassandra cluster's topology (which nodes belong to the cluster) and schema (what * keyspaces, tables, etc. exist in this cluster). * <p/> * Preconditions: * - a Cassandra cluster is running and accessible through the contacts points identified by CONTACT_POINTS and PORT. * <p/> * Side effects: none. * * @see <a href="http://datastax.github.io/java-driver/manual/">Java driver online manual</a> */ public class ReadTopologyAndSchemaMetadata { static String[] CONTACT_POINTS = {"127.0.0.1"}; static int PORT = 9042; public static void main(String[] args) { Cluster cluster = null; try { cluster = Cluster.builder() .addContactPoints(CONTACT_POINTS).withPort(PORT) .build(); Metadata metadata = cluster.getMetadata(); System.out.printf("Connected to cluster: %s%n", metadata.getClusterName()); for (Host host : metadata.getAllHosts()) { System.out.printf("Datatacenter: %s; Host: %s; Rack: %s%n", host.getDatacenter(), host.getAddress(), host.getRack()); } for (KeyspaceMetadata keyspace : metadata.getKeyspaces()) { for (TableMetadata table : keyspace.getTables()) { System.out.printf("Keyspace: %s; Table: %s%n", keyspace.getName(), table.getName()); } } } finally { if (cluster != null) cluster.close(); } } }