transient關鍵字的使用

transient這個關鍵字不怎麼常用在web應用開發中。但也是要知道有這麼一個東西的。主要的用途在序列化中，下面貼上一段來自網上的例子就明白了

import java.io.*;

import java.util.*;

class logon implements serializable {

    private static final long serialversionuid = -732613846174452100l;

    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.tostring() + "\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(

            system.out.println();

            system.out.println("recovering object at " + new date());

            a = (logon) in.readobject();

            system.out.println("logon a = " + a);

        } catch (exception e) {

            e.printstacktrace();

        }

} // /:~