logon.java

网络书店的设计与实现 网络书店的设计与实现

//: c11:Logon.java
// From 'Thinking in Java, 2nd ed.' by Bruce Eckel
// www.BruceEckel.com. See copyright notice in CopyRight.txt.
// Demonstrates the "transient" keyword.
import java.io.*;
import java.util.*;

class Logon implements Serializable {
  private Date date = new Date();
  private String username;
  private transient String password;
  Logon(String name, String pwd) {
    username = name;
    password = pwd;
  }
  public String toString() {
    String pwd =
      (password == null) ? "(n/a)" : password;
    return "logon info: \n   " +
      "username: " + username +
      "\n   date: " + date +
      "\n   password: " + pwd;
  }
  public static void main(String[] args) {
    Logon a = new Logon("Hulk", "myLittlePony");
    System.out.println( "logon a = " + a);
    try {
      ObjectOutputStream o =
        new ObjectOutputStream(
          new FileOutputStream("Logon.out"));
      o.writeObject(a);
      o.close();
      // Delay:
      int seconds = 5;
      long t = System.currentTimeMillis()
             + seconds * 1000;
      while(System.currentTimeMillis() < t)
        ;
      // Now get them back:
      ObjectInputStream in =
        new ObjectInputStream(
          new FileInputStream("Logon.out"));
      System.out.println(
        "Recovering object at " + new Date());
      a = (Logon)in.readObject();
      System.out.println( "logon a = " + a);
    } catch(Exception e) {
      e.printStackTrace();
    }
  }
} ///:~