Java IO流——序列化的基本操作

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对象序列化，就是将Object转换成byte序列，反之叫对象的反序列化

序列化流(ObjectOutputStream),是过滤流—-writeObject 反序列化流(ObjectInputStream)—readObject

序列化接口(Serializable) 对象必须实现序列化接口，才能进行序列化，否则将出现异常这个接口，没有任何方法，只是一个标准

transient关键字
private void writeObject(java.io.ObjectOutputStream s)
throws java.io.IOException {}
private void readObject(java.io.ObjectInputStream s)
throws java.io.IOException, ClassNotFoundException {}
分析ArrayList源码中序列化和反序列化的问题

序列化与反序列化示例代码：

package com.sample.io;import java.io.Serializable;public class Student implements Serializable{    private String stuno;    private String stuname;    //该元素不会进行jvm默认的序列化,也可以自己完成这个元素的序列化    private transient int stuage;      public Student(String stuno, String stuname, int stuage) {        super();        this.stuno = stuno;        this.stuname = stuname;        this.stuage = stuage;    }    public String getStuno() {        return stuno;    }    public void setStuno(String stuno) {        this.stuno = stuno;    }    public String getStuname() {        return stuname;    }    public void setStuname(String stuname) {        this.stuname = stuname;    }    public int getStuage() {        return stuage;    }    public void setStuage(int stuage) {        this.stuage = stuage;    }    @Override    public String toString() {        return "Student [stuno=" + stuno + ", stuname=" + stuname + ", stuage="                + stuage + "]";    }     private void writeObject(java.io.ObjectOutputStream s)                throws java.io.IOException{         s.defaultWriteObject();//把jvm能默认序列化的元素进行序列化操作         s.writeInt(stuage);//自己完成stuage的序列化     }     private void readObject(java.io.ObjectInputStream s)                throws java.io.IOException, ClassNotFoundException{          s.defaultReadObject();//把jvm能默认反序列化的元素进行反序列化操作          this.stuage = s.readInt();//自己完成stuage的反序列化操作    }}package com.sample.io;import java.io.FileInputStream;import java.io.ObjectInputStream;public class ObjectSeriaDemo1 {    public static void main(String[] args) throws Exception{        String file = "demo/obj.dat";        //1.对象的序列化        /*ObjectOutputStream oos = new ObjectOutputStream(                new FileOutputStream(file));        Student stu = new Student("10001", "张三", 20);        oos.writeObject(stu);        oos.flush();        oos.close();*/        ObjectInputStream ois = new ObjectInputStream(                new FileInputStream(file));        Student stu = (Student)ois.readObject();        System.out.println(stu);        ois.close();    }}

5.序列化中子类和父类构造函数的调用问题

代码示例：

package com.sample.io;import java.io.FileInputStream;import java.io.ObjectInputStream;import java.io.Serializable;public class ObjectSeriaDemo2 {    public static void main(String[] args) throws Exception{        /*ObjectOutputStream oos = new ObjectOutputStream(                new FileOutputStream("demo/obj1.dat"));        Foo2 foo2 = new Foo2();        oos.writeObject(foo2);        oos.flush();        oos.close();*/        //反序列化是否递归调用父类的构造函数        /*ObjectInputStream ois = new ObjectInputStream(                new FileInputStream("demo/obj1.dat"));        Foo2 foo2 = (Foo2)ois.readObject();        System.out.println(foo2);        ois.close();*/        /*ObjectOutputStream oos = new ObjectOutputStream(                new FileOutputStream("demo/obj1.dat"));        Bar2 bar2 = new Bar2();        oos.writeObject(bar2);        oos.flush();        oos.close();*/        ObjectInputStream ois = new ObjectInputStream(                new FileInputStream("demo/obj1.dat"));        Bar2 bar2 = (Bar2)ois.readObject();        System.out.println(bar2);        ois.close();        /*         * 对子类对象进行反序列化操作时，         * 如果其父类没有实现序列化接口         * 那么其父类的构造函数会被调用         */    }}/* *   一个类实现了序列化接口，那么其子类都可以进行序列化 */class Foo implements Serializable{      public Foo(){        System.out.println("foo...");    }}class Foo1 extends Foo{    public Foo1(){        System.out.println("foo1...");    }}class Foo2 extends Foo1{    public Foo2(){        System.out.println("foo2...");    }}class Bar{    public Bar(){        System.out.println("bar");    }}class Bar1 extends Bar{    public Bar1(){        System.out.println("bar1..");    }}class Bar2 extends Bar1 implements Serializable{    public Bar2(){        System.out.println("bar2...");    }}

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