public class Student implements java.io.Serializable  {    
    private String name;
    private int age;
    private String gender;
    private transient String password;
    public Student(String name, int age,String gender){
        this.name=name;
        this.age=age;
        this.gender=gender;   
    }
    
    public Student(String name, int age,String gender,String password){
        this.name=name;
        this.age=age;
        this.gender=gender; 
        this.password=password;
    }
    public String getName() {
        return name;
    }
    public void setName(String name) {
        this.name = name;
    }
    public int getAge() {
        return age;
    }
    public void setAge(int age) {
        this.age = age;
    }
    public String getGender() {
        return gender;
    }
    public void setGender(String gender) {
        this.gender = gender;
    }
    
    public String getPassword() {
        return password;
    }
    public void setPassword(String password) {
        this.password = password;
    }
}
import java.io.*;

public class SerializableObj {
    public static void main(String[] args) throws IOException, ClassNotFoundException {
        ObjectOutputStream oos = null;
        ObjectInputStream ois=null;
        try {
            // 创建ObjectOutputStream输出流
            oos = new ObjectOutputStream(new FileOutputStream(
                    "c:\\myDoc\\stu.txt"));
            Student stu = new Student("安娜", 30, "女","aaaa");
            System.out.println("姓名为:"+stu.getName());
            System.out.println("年龄为:"+stu.getAge());
            System.out.println("性别为:"+stu.getGender());
            System.out.println("密码为:"+stu.getPassword());
            // 对象序列化,写入输出流
            oos.writeObject(stu);
            
            //创建ObjectInputStream输入流
            ois=new ObjectInputStream(new FileInputStream("c:\\myDoc\\stu.txt"));
            //反序列化,强转类型
            Student stu1=(Student)ois.readObject();
            //输出生成后对象信息
            System.out.println("姓名为:"+stu1.getName());
            System.out.println("年龄为:"+stu1.getAge());
            System.out.println("性别为:"+stu1.getGender());
            System.out.println("密码为:"+stu1.getPassword());
        } catch (IOException ex) {
            ex.printStackTrace();
        } finally {
            try {
                if (oos != null) {
                    oos.close();
                }
                if (ois != null) {
                    ois.close();
                }
            }catch (IOException ex) {
                ex.printStackTrace();
            }                     
        }
    }
}
public class Test {
    
    private String name;
    public Test(){
        this.name="小新";
    }
    public Test(String name){
        System.out.println("我是:"+this.name);
    }
    public static void main(String[] args) {
        Test test=new Test("小强");
    }
}