CommunicatorServerHandler.java

package org.opensource.clearpool.console;

import java.io.IOException;
import java.lang.management.ManagementFactory;
import java.net.ServerSocket;
import java.util.HashMap;
import java.util.Map;

import javax.management.MBeanServer;
import javax.management.ObjectName;

import org.opensource.clearpool.configuration.console.Console;
import org.opensource.clearpool.console.hook.HtmlAdaptorHook;
import org.opensource.clearpool.core.ConnectionPoolManager;
import org.opensource.clearpool.exception.ConnectionPoolMBeanException;
import org.opensource.clearpool.logging.PoolLogger;
import org.opensource.clearpool.logging.PoolLoggerFactory;

import com.sun.jdmk.comm.CommunicatorServer;

/**
 * This class is used to control MBean.
 *
 * @author xionghui
 * @date 26.07.2014
 * @version 1.0
 */
class CommunicatorServerHandler {
  private static final PoolLogger LOGGER =
      PoolLoggerFactory.getLogger(CommunicatorServerHandler.class);

  private static MBeanServer server = ManagementFactory.getPlatformMBeanServer();

  // this map is used to unregister ObjectName while remove the pool
  private static Map<String, ObjectNameCarry> objectNameMap =
      new HashMap<String, ObjectNameCarry>();

  private static CommunicatorServer communicatorServer;

  /**
   * Register a MBean
   */
  public static void registerMBean(ConnectionPoolManager pool, String mbeanName, String poolName) {
    ConnectionPoolMBean bean = new ConnectionPool(pool);
    try {
      ObjectName objectName = new ObjectName(mbeanName);
      server.registerMBean(bean, objectName);
      ObjectNameCarry carry = new ObjectNameCarry(objectName, mbeanName);
      objectNameMap.put(poolName, carry);
    } catch (Exception e) {
      LOGGER.error("registerMBean error: ", e);
      throw new ConnectionPoolMBeanException(e);
    }
    LOGGER.info("register " + poolName + "'s MBean:" + mbeanName);
  }

  /**
   * Unregister a MBean
   */
  public static void unregisterMBean(String poolName) {
    ObjectNameCarry carry = objectNameMap.get(poolName);
    if (carry == null) {
      return;
    }
    ObjectName objectName = carry.objectName;
    String mbeanName = carry.mbeanName;
    try {
      server.unregisterMBean(objectName);
    } catch (Exception e) {
      // If we use Unregister button to stop it,we will get this exception
      // and log it.
      LOGGER.error("unregisterMBean error: ", e);
    }
    LOGGER.info("unregister " + poolName + "'s MBean:" + mbeanName);
  }

  /**
   * Start communicatorServer
   */
  public static void start() {
    if (communicatorServer != null) {
      return;
    }
    checkPort(MBeanFacade.console.getPort());
    // start it.
    communicatorServer = HtmlAdaptorHook.startHook(server);
  }

  /**
   * check if port is valid.
   */
  private static void checkPort(int port) {
    try {
      ServerSocket server = new ServerSocket(port);
      server.close();
    } catch (IOException e) {
      LOGGER.error("checkPort error: ", e);
      throw new ConnectionPoolMBeanException(Console.PORT + " is used");
    }
  }

  /**
   * Stop HtmlAdaptorServer,note:never stop the thread,instead of we should set stopRequested true
   * and close sockListen.Want to know the reason,please to see the source of CommunicatorServer and
   * HtmlAdaptorServer.
   */
  public static void stop() {
    if (communicatorServer != null) {
      // stop it
      HtmlAdaptorHook.stop(communicatorServer);
      // help gc
      communicatorServer = null;
      objectNameMap = new HashMap<String, ObjectNameCarry>();
    }
  }

  /**
   * This class used to carry mbeanName of the ObjectName,we can't log mbeanName with it while we
   * unregister the MBean.
   *
   * @author xionghui
   * @date 26.07.2014
   * @version 1.0
   */
  private static class ObjectNameCarry {
    ObjectName objectName;
    String mbeanName;

    ObjectNameCarry(ObjectName objectName, String mbeanName) {
      this.objectName = objectName;
      this.mbeanName = mbeanName;
    }
  }
}