priceserverimpl.java

来自「100多M的J2EE培训内容」· Java 代码 · 共 174 行

package bible.rmi.example3;

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

/**
 * PriceServerImpl implements the PriceServer remote interface, providing
 * prices on securities for remote clients.
 */
public class PriceServerImpl implements PriceServer {

  // Stock price database, implemented as a Hashtable.

  /** stockTable           */
  private Hashtable stockTable = null;

  // Hostname of the box where the server is running.

  /** hostname           */
  private String hostname = null;

  /**
   * Creates the stock price 'database'.
   */
  public PriceServerImpl() {

    stockTable = new Hashtable();

    Float f = new Float(0);
    stockTable.put("SUNW", f.valueOf("20"));
    stockTable.put("INTC", f.valueOf("30"));
    stockTable.put("BEAS", f.valueOf("40"));
  }

  /**
   * Returns the price of the given security.
   * @param symbol
   */
  public float getPrice(String symbol) throws java.rmi.RemoteException {

    Float f = (Float) stockTable.get(symbol);
    System.out.println("PriceServer: Call to getPrice for symbol : "
                       + symbol);

    return f.floatValue();
  }

  /**
   * Sets the price for the given security.
   * @param symbol
   * @param price
   */
  public void setPrice(String symbol, float price) throws java.rmi.RemoteException{

    Float f = new Float(price);
    stockTable.put(symbol, f);
    System.out.println("PriceServer: Call to setPrice for " + symbol + " to "
                       + price);
  }

  /**
   * Returns all ticker symbols in this server's database.
   */
  public String[] getSecurities() throws java.rmi.RemoteException{

    if (stockTable.size() > 0) {
      String[]    securities = new String [stockTable.size()];
      Enumeration enum       = stockTable.keys();
      int         i          = 0;
      while (enum.hasMoreElements()) {
        securities [i] = (String) enum.nextElement();

        i++;
      }

      return securities;
    }

    return null;
  }

  /**
   * Submits an order for the client, then asynchronously
   * notifies that client when the order gets executed.
   * @param order Order to be submitted by the client.
   * @param clientRef Remote reference for the client, used for asynchronous execution notification.
   */
  public void enterMarketOrder(Order order, ExecutionAlert clientRef) throws java.rmi.RemoteException{

    // Multi-threaded this so it returns to the client right away and
    // does its execution/callback work later.
    System.out.println("A client has placed an order!");
    System.out.println("Time: " + new Date());
    System.out.println(order + "\n");

    DoExecution exec = new DoExecution(order, clientRef);
    new Thread(exec).start();
  }

  /**
   * Inner-class providing asynchronous client callbacks of order activity.
   */
  private class DoExecution implements Runnable {

    /** order           */
    private Order order;

    /** client           */
    private ExecutionAlert client;

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

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

      try {

        // Wait 10 seconds to simulate submission of the order
        // to a stock exchange.
        Thread.currentThread().sleep(10000);

        // Create an Execution instance and execute the order.
        Execution execution = new Execution();

        // Copy order data into the execution.
        execution.setNumber(order.getNumber());
        execution.setSymbol(order.getSymbol());
        execution.setShares(order.getShares());

        // Execute at the stock's current price and write a status
        // message to standard output.
        execution.setPrice(getPrice(order.getSymbol()));
        System.out.println("An order has been executed!");
        System.out.println("Time: " + new Date());
        System.out.println(execution + "\n");

        // Make a remote call to the client to notify them
        // of the execution.
        client.notifyOfExecution(execution);
      } catch (Exception e) {
        e.printStackTrace();
      }
    }
  }

  /**
   * Instanciates and binds a PriceServer.
   * @param args
   */
  public static void main(String[] args) {

    try {
      PriceServerImpl server = new PriceServerImpl();
      Context         ctx    = new InitialContext();
      ctx.bind(PRICESERVERNAME, server);
      System.out.println("PriceServer was started and bound in the registry "
                         + "to the name " + PRICESERVERNAME);
    } catch (Exception e) {
      e.printStackTrace();
      System.exit(1);
    }
  }
}