executetrade.java

来自「100多M的J2EE培训内容」· Java 代码 · 共 125 行

package bible.rmi.example4;

import java.rmi.*;
import javax.ejb.*;
import javax.naming.*;
import java.util.*;

/**
 * Implementation of the ExecuteTrade Session EJB.
 * Executes a trade and notifies via client callback of execution.
 */
public class ExecuteTrade implements SessionBean {

  /** sessionContext           */
  private SessionContext sessionContext;

  /**
   * Method ejbCreate
   *
   *
   */
  public void ejbCreate() {}

  /**
   * Method ejbRemove
   *
   *
   */
  public void ejbRemove() {}

  /**
   * Method ejbActivate
   *
   *
   */
  public void ejbActivate() {}

  /**
   * Method ejbPassivate
   *
   *
   */
  public void ejbPassivate() {}

  /**
   * Method setSessionContext
   *
   *
   * @param context
   *
   */
  public void setSessionContext(SessionContext context) {
    sessionContext = context;
  }

  /**
   * Executes an order and alerts the client of the execution.
   * @param order Order to be executed.
   * @param alert Client to be alerted upon execution.
   * @throws RemoteException
   */
  public void executeTrade(Order order, ExecutionAlert alert)
    throws RemoteException {

    // Multi-threaded this so it returns to the client right away and
    // does its execution/callback work later.
    DoExecution exec = new DoExecution(order, alert);
    new Thread(exec).start();
  }

  /**
   * DoExecution
   */
  private class DoExecution implements Runnable {

    /** order           */
    private Order order;

    /** client           */
    private ExecutionAlert client;

    /**
     * Constructor DoExecution
     *
     *
     * @param ord
     * @param alert
     *
     */
    public DoExecution(Order ord, ExecutionAlert alert) {
      order  = ord;
      client = alert;
    }

    /**
     * Method run
     *
     *
     */
    public void run() {

      try {
        Thread.currentThread().sleep(15000);  // sleep 15 seconds.

        InitialContext ctx       = Environment.getInitialContext();
        PriceServer    server    =
          (PriceServer) ctx.lookup(PriceServer.PRICESERVERNAME);
        Execution      execution = new Execution();
        execution.setNumber(order.getNumber());
        execution.setPrice(server.getPrice(order.getSymbol()));

        // execution.setPrice(order.getPrice());
        execution.setShares(order.getShares());
        execution.setSymbol(order.getSymbol());
        System.out.println("An order has been executed!");
        System.out.println("Time: " + new Date());
        System.out.println(execution + "\n");
        client.notifyOfExecution(execution);
      } catch (Exception e) {
        e.printStackTrace();
      }
    }
  }
}