gistfile1.java

package org.apache.cassandra.tools;

import java.io.IOException;
import java.util.Arrays;
import java.util.HashMap;
import java.util.Map;

import javax.management.JMX;
import javax.management.MBeanServerConnection;
import javax.management.MalformedObjectNameException;
import javax.management.ObjectName;
import javax.management.remote.JMXConnector;
import javax.management.remote.JMXConnectorFactory;
import javax.management.remote.JMXServiceURL;

import org.apache.cassandra.service.StorageServiceMBean;

public class Topology
{
    private static final String fmtUrl = "service:jmx:rmi:///jndi/rmi://%s:%d/jmxrmi";
    private static final String ssObjName = "org.apache.cassandra.db:type=StorageService";
    private static final int defaultPort = 7199;
    final String host;
    final int port;

    private JMXConnector jmxc;
    private MBeanServerConnection mbeanServerConn;
    private StorageServiceMBean ssProxy;

    public Topology(String host) throws IOException
    {
        this(host, defaultPort);
    }

    public Topology(String host, int port) throws IOException
    {
        this.host = host;
        this.port = port;
        connect();
    }

    /**
     * Create a connection to the JMX agent and setup the M[X]Bean proxies.
     *
     * @throws IOException on connection failures
     */
    private void connect() throws IOException
    {
        JMXServiceURL jmxUrl = new JMXServiceURL(String.format(fmtUrl, host, port));
        Map<String,Object> env = new HashMap<String,Object>();
        jmxc = JMXConnectorFactory.connect(jmxUrl, env);
        mbeanServerConn = jmxc.getMBeanServerConnection();

        try
        {
            ObjectName name = new ObjectName(ssObjName);
            ssProxy = JMX.newMBeanProxy(mbeanServerConn, name, StorageServiceMBean.class);
        } catch (MalformedObjectNameException e)
        {
            throw new RuntimeException(
                    "Invalid ObjectName? Please report this as a bug.", e);
        }
    }

    public static void main(String[] args) throws Exception
    {
        //args = new String[]{"26827489534178531658985394796824233139"};
        args = new String[]{"41929325298747031914175438363534668486"};
        new Topology("localhost", 7300).ssProxy.relocate(Arrays.asList(args));
    }
}