org.sglover.alfrescoextensions.common.CassandraSession.java Source code

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Here is the source code for org.sglover.alfrescoextensions.common.CassandraSession.java

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/*
 * Copyright 2015 Alfresco Software, Ltd.  All rights reserved.
 *
 * License rights for this program may be obtained from Alfresco Software, Ltd. 
 * pursuant to a written agreement and any use of this program without such an 
 * agreement is prohibited. 
 */
package org.sglover.alfrescoextensions.common;

import java.util.LinkedList;
import java.util.List;
import java.util.StringTokenizer;

import javax.annotation.PostConstruct;

import org.springframework.beans.factory.annotation.Value;
import org.springframework.stereotype.Component;

import com.datastax.driver.core.Cluster;
import com.datastax.driver.core.KeyspaceMetadata;
import com.datastax.driver.core.Session;
import com.datastax.driver.core.policies.DCAwareRoundRobinPolicy;
import com.datastax.driver.core.policies.DefaultRetryPolicy;
import com.datastax.driver.core.policies.TokenAwarePolicy;

/**
 * 
 * @author sglover
 *
 */
@Component
public class CassandraSession {
    @Value("${cassandra.host}")
    private String hosts;

    @Value("${cassandra.keyspace}")
    private String keyspace;

    private boolean recreate = false;

    private Cluster cluster;
    private Session cassandraSession;

    public CassandraSession(String hosts, String keyspace, boolean recreate) {
        this.hosts = hosts;
        this.keyspace = keyspace;
        this.recreate = recreate;
    }

    public CassandraSession() {
    }

    public CassandraSession(boolean recreate) {
        this.recreate = recreate;
    }

    @PostConstruct
    public void init() {
        this.cassandraSession = buildCassandraSession(hosts);

        if (recreate) {
            deleteKeyspace();
            createKeyspace();
        } else {
            if (cassandraSession.getCluster().getMetadata().getKeyspace(keyspace) == null) {
                createKeyspace();
            }
        }
    }

    public String getKeyspace() {
        return keyspace;
    }

    private Session buildCassandraSession(String hostsStr) {
        List<String> hosts = new LinkedList<>();
        StringTokenizer st = new StringTokenizer(hostsStr, ",");
        while (st.hasMoreTokens()) {
            hosts.add(st.nextToken());
        }

        this.cluster = Cluster.builder().addContactPoints(hosts.toArray(new String[0]))
                .withRetryPolicy(DefaultRetryPolicy.INSTANCE)
                .withLoadBalancingPolicy(new TokenAwarePolicy(new DCAwareRoundRobinPolicy())).build();
        Session session = cluster.connect();
        return session;
    }

    private void deleteKeyspace() {
        cassandraSession.execute("DROP KEYSPACE IF EXISTS " + keyspace + ";");
        //        KeyspaceMetadata keySpaceMetadata = cassandraSession.getCluster().getMetadata().getKeyspace("alfresco");
        //        if(keySpaceMetadata != null)
        //        {
        //            cassandraSession.execute("DROP KEYSPACE IF EXISTS alfresco;");
        //        }
        KeyspaceMetadata keySpaceMetadata = null;
        do {
            keySpaceMetadata = cassandraSession.getCluster().getMetadata().getKeyspace(keyspace);
        } while (keySpaceMetadata != null);
    }

    private void createKeyspace() {
        cassandraSession.execute("CREATE KEYSPACE IF NOT EXISTS " + keyspace + " WITH replication "
                + "= {'class':'SimpleStrategy', 'replication_factor':3};");
    }

    public Cluster getCluster() {
        return cluster;
    }

    public Session getCassandraSession() {
        return cassandraSession;
    }

    public void shutdown() {
        cassandraSession.getCluster().close();
    }
}