Java对对象的序列化和反序列化

Java提供了将对象以字节的形式写入到磁盘中，在需要的时候在从磁盘中恢复的功能，在网络传输中非常有用，下面将代码贴上，分别用两种形式实现了对象的序列化，其中第二种当时能将指定的变量序列化，更加人性化的随心所欲

    package com.bird.thinking; import java.io.FileInputStream; import java.io.FileOutputStream; import java.io.ObjectInputStream; import java.io.ObjectOutputStream; import java.io.Serializable; /** * @use 实现对对象的序列化和反序列化 * @author Bird * */ public class Data { public static void writeObject() throws Exception{ Worm worm = new Worm("Bird"); ObjectOutputStream out = new ObjectOutputStream(new FileOutputStream("d://worm.out")); out.writeObject(worm); out.close();//关闭的同时也刷新清空了缓冲区 } public static void readObject() throws Exception{ ObjectInputStream in = new ObjectInputStream(new FileInputStream("d://worm.out")); Worm s2 = (Worm) in.readObject(); System.out.println(s2); } public static void main(String[] args) throws Exception{ // writeObject(); readObject(); } } class Worm implements Serializable{ private static final long serialVersionUID = 1L; private String name = null; public Worm(String name){ this.name = name; } public String toString(){ return name; } }

下面是第二种方式

package com.bird.thinking; import java.io.Externalizable; import java.io.FileInputStream; import java.io.FileNotFoundException; import java.io.FileOutputStream; import java.io.IOException; import java.io.ObjectInput; import java.io.ObjectInputStream; import java.io.ObjectOutput; import java.io.ObjectOutputStream; /** * @use 第二种可控制序列化变量个数的方式 * @author Bird * */ public class Blip3 implements Externalizable { private int i; private String s;//没有实例化 public Blip3(){ System.out.println("Blip3 Constructor!!"); } //注意 这里的s没有实例化 public Blip3(String x, int a){ System.out.println("Blip3(String x, int a)"); s = x; i = a; //s 和 i实例化在非默认构造函数中 } public String toString(){ return s + i; } public void writeExternal(ObjectOutput out){//可选择写入变量 System.out.println("Blip3.writeExternal"); try { out.writeObject(s); out.writeInt(i); } catch (IOException e) { throw new RuntimeException(e); }//必须进行这两项，否则就一个变量也不出初始化 } public void readExternal(ObjectInput in){//可选择读入数据 System.out.println("Blip3.readExternal"); try { s = (String)in.readObject(); i = in.readInt(); } catch (ClassNotFoundException e) { } catch (IOException e) { throw new RuntimeException(e); } } public void read() throws FileNotFoundException, IOException, ClassNotFoundException{//读取序列化的类 ObjectInputStream in = new ObjectInputStream(new FileInputStream("d://Blip3.out")); System.out.println("Revovering b3"); Blip3 b3 = (Blip3)in.readObject(); System.out.println(b3); } public void write() throws Exception{//写入对象 Blip3 b3 = new Blip3("A String", 47); System.out.println(b3); ObjectOutputStream o = new ObjectOutputStream(new FileOutputStream("d://Blip3.out")); System.out.println("Saving Object"); o.writeObject(b3); o.close(); } public static void main(String[] args) throws Exception{ Blip3 b = new Blip3(); // b.write(); b.read(); } }
输出结果为

Blip3 Constructor!! Blip3(String x, int a) A String47 Saving Object Blip3.writeExternal
Blip3 Constructor!! Revovering b3 Blip3 Constructor!! Blip3.readExternal A String47