eu.redzoo.article.planetcassandra.reactive.CassandraDB.java Source code

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Here is the source code for eu.redzoo.article.planetcassandra.reactive.CassandraDB.java

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/*
 * 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 eu.redzoo.article.planetcassandra.reactive;

import java.io.Closeable;
import java.io.File;
import java.io.IOException;

import java.util.UUID;

import com.datastax.driver.core.Cluster;
import com.datastax.driver.core.Session;
import com.google.common.base.Charsets;
import com.google.common.collect.ImmutableSet;
import com.google.common.io.Files;
import com.google.common.io.Resources;

public class CassandraDB implements Closeable {

    private Cluster cluster;
    private final Session session;
    private final String keyspace;

    /**
     * @return a new cassandra database instance (SimpleStrategy with RF=1) with random keyspacename
     */
    public static CassandraDB newInstance() {
        return newInstance("ks_" + UUID.randomUUID().toString().replace("-", ""));
    }

    /**
     * @param keyspacename  the keyspacename to use 
     * @return  new cassandra database instance (SimpleStrategy with RF=1) with requested keyspacename
     */
    public static CassandraDB newInstance(String keyspacename) {
        return new CassandraDB(keyspacename);
    }

    private CassandraDB(String keyspacename) {
        this.keyspace = keyspacename;
        try {
            EmbeddedCassandra.start();

            cluster = Cluster.builder()
                    .addContactPointsWithPorts(ImmutableSet.of(EmbeddedCassandra.getNodeaddress())).build();

            createKeyspace(keyspacename);

            session = cluster.connect(keyspacename);
        } catch (IOException ioe) {
            throw new RuntimeException(ioe);
        }
    }

    private void createKeyspace(String keyspacename) {
        try (Session session = cluster.connect("system")) {
            session.execute("create keyspace " + keyspacename
                    + " WITH REPLICATION = { 'class' : 'SimpleStrategy', 'replication_factor' : 1 };");
        }
    }

    public void close() {
        cluster.close();
    }

    public int getPort() {
        return EmbeddedCassandra.getPort();
    }

    public String getKeyspace() {
        return keyspace;
    }

    public Session getSession() {
        return session;
    }

    /**
     * executes a CQL file 
     * 
     * @param cqlFile    the CQL file name 
     * @throws IOException  if the file could not be found
     */
    public void executeCqlFile(String cqlFile) throws IOException {
        File file = new File(cqlFile);
        if (file.exists()) {
            executeCql(Files.toString(new File(cqlFile), Charsets.UTF_8));
        } else {
            executeCql(Resources.toString(Resources.getResource(cqlFile), Charsets.UTF_8));
        }
    }

    /**
     * executes a CQL file. CQL processing errors will be ignored 
     * 
     * @param cqlFile    the CQL file name 
     * @throws IOException  if the file could not be found
     */
    public void tryExecuteCqlFile(String cqlFile) {
        try {
            File file = new File(cqlFile);
            if (file.exists()) {
                tryExecuteCql(Files.toString(new File(cqlFile), Charsets.UTF_8));
            } else {
                tryExecuteCql(Resources.toString(Resources.getResource(cqlFile), Charsets.UTF_8));
            }
        } catch (IOException ioe) {
            throw new RuntimeException(cqlFile + " not found");
        }
    }

    /**
     * executes CQL 
     * 
     * @param cql    the CQL to execute  
     */
    public void executeCql(String cql) {
        session.execute(cql);
    }

    /**
     * executes CQL. CQL processing errors will be ignored 
     * 
     * @param cql  the CQL to execute
     */
    public void tryExecuteCql(String cql) {
        try {
            session.execute(cql);
        } catch (RuntimeException e) {
            e.printStackTrace();
        }
    }
}