实现Serializable接口到底什么用啊？
下面是个书上的小例子，如果没有实现Serializable和实现了有什么区别么？

附小程序：
import java.io.*;
import java.util.*;

class ObjectFileTest
{
public static void main(String[] args)
{
Manager boss = new Manager( "Carl Cracker ", 80000, 1987, 12, 15);
boss.setBonus(5000);

Employee[] staff = new Employee[3];

staff[0] = boss;
staff[1] = new Employee( "Harry Hacker ", 50000, 1989, 10, 1);
staff[2] = new Employee( "Tony Tester ", 40000, 1990, 3, 15);

try
{
// save all employee records to the file employee.dat
ObjectOutputStream out = new ObjectOutputStream(new FileOutputStream( "employee.dat "));
out.writeObject(staff);
out.close();

// retrieve all records into a new array
ObjectInputStream in = new ObjectInputStream(new FileInputStream( "employee.dat "));
Employee[] newStaff = (Employee[]) in.readObject();
in.close();

// print the newly read employee records
for (Employee e : newStaff)
System.out.println(e);
}
catch (Exception e)
{
e.printStackTrace();
}
}
}

class Employee implements Serializable
{
public Employee() {}

public Employee(String n, double s, int year, int month, int day)
{
name = n;
salary = s;
GregorianCalendar calendar = new GregorianCalendar(year, month - 1, day);

hireDay = calendar.getTime();
}

public String getName()
{
return name;
}

public double getSalary()
{
return salary;
}

public Date getHireDay()
{
return hireDay;
}

public void raiseSalary(double byPercent)
{
double raise = salary * byPercent / 100;
salary += raise;
}

public String toString()
{
return getClass().getName()
+ "[name= " + name
+ ",salary= " + salary
+ ",hireDay= " + hireDay
+ "] ";
}

private String name;
private double salary;
private Date hireDay;
}

class Manager extends Employee
{
/**
@param n the employee 's name
@param s the salary
@param year the hire year
@param month the hire month
@param day the hire day
*/
public Manager(String n, double s, int year, int month, int day)
{
super(n, s, year, month, day);
bonus = 0;
}

public double getSalary()
{
double baseSalary = super.getSalary();
return baseSalary + bonus;
}

public void setBonus(double b)
{
bonus = b;
}

public String toString()
{

return super.toString()
+ "[bonus= " + bonus
+ "] ";
}

private double bonus;
}


[解决办法]
Serializable只是一个标识，没有方法，所以有没有implements Serializable类本身没什么太大的变化（除了继承声明以外），它只是告诉虚拟机可以用默认的序列化机制来序列化此类。
当然你也可以自己写readObject, writeObject方法，自己来实现序列化。
你可以搜索Google，有很多这方面的介绍。
[解决办法]
什么叫做可以序列化

这个问题就不用在这里问吧,
你也太懒了, 随便一本基本的Java书上都会讲序列化.

你写的这个例子在 < <Core Java> > ( < <Java 核心技术> > ) 上面有, 这本书上就有很详细的解释.

[解决办法]
在网络上可以以流的形式传输
[解决办法]
实现此接口 即可进行 流 的传输
[解决办法]
使网络能够传输对象
[解决办法]
实现了serializable就可以实现对象的序列化