java中Serializable序列化与反序列化的作用
首先解释两个概念,何为序列化?何为反序列化?
序列化:将对象转化成流的过程称为序列化
反序列化:将流转化成对象的过程称之为反序列化
序列化与反序列化必须遵守的原则
a) Java对象
在java中要想使一个java对象可以实现序列化与反序列化,必须让该类实现java.io.Serializable接口
java.io.Serializable接口定义如下:
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publicinterface Serializable { } |
从上述定义中可以看到该接口中未定义任何方法,这大大的简化了开发者
b) 序列化主要依赖java.io.ObjectOutputStream类,该类对java.io.FileOutputStream进一步做了封装,这里主要使用ObjectOutputStream类的writeObject()方法实现序列化功能
Demo:
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/** *将对象序列化到磁盘文件中 *@paramo *@throwsException */ publicstaticvoid writeObject(Object o) throws Exception{ File f=new File("d:""user.tmp"); if(f.exists()){ f.delete(); } FileOutputStream os=new FileOutputStream(f); //ObjectOutputStream 核心类 ObjectOutputStream oos=new ObjectOutputStream(os); oos.writeObject(o); oos.close(); os.close(); } |
c) 反序列化主要依赖java.io.ObjectInputStream类,该类对java.io.InputStream进一步做了封装,这里主要使用ObjectInputStream类的readObject()方法实现序列化功能
Demo:
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/** *反序列化,将磁盘文件转化为对象 *@paramf *@return *@throwsException */ publicstatic User readObject(File f) throws Exception{ InputStream is=new FileInputStream(f); //ObjectOutputStream 核心类 ObjectInputStream ois=new ObjectInputStream(is); return (User)ois.readObject(); } |
贴出完整的demo
Java对象:
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package com.io.bean; import java.io.Serializable; publicclass User implements Serializable {
privateintuserId; private String userName; private String userSex; privateintuserAge; publicint getUserAge() { returnuserAge; } publicvoid setUserAge(int userAge) { this.userAge = userAge; } publicint getUserId() { returnuserId; } publicvoid setUserId(int userId) { this.userId = userId; } public String getUserName() { returnuserName; } publicvoid setUserName(String userName) { this.userName = userName; } public String getUserSex() { returnuserSex; } publicvoid setUserSex(String userSex) { this.userSex = userSex; } @Override public String toString() { returnthis.getUserId() + " " + this.getUserName() + " " + this.getUserSex() + " " + this.getUserAge(); } } |
序列化与反序列化
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package com.io.test; import java.io.File; import java.io.FileInputStream; import java.io.FileOutputStream; import java.io.InputStream; import java.io.ObjectInputStream; import java.io.ObjectOutputStream; import com.io.bean.User; publicclass TestSerializable { /** *将对象序列化到磁盘文件中 *@paramo *@throwsException */ publicstaticvoid writeObject(Object o) throws Exception{ File f=new File("d:""user.tmp"); if(f.exists()){ f.delete(); } FileOutputStream os=new FileOutputStream(f); //ObjectOutputStream 核心类 ObjectOutputStream oos=new ObjectOutputStream(os); oos.writeObject(o); oos.close(); os.close(); }
/** *反序列化,将磁盘文件转化为对象 *@paramf *@return *@throwsException */ publicstatic User readObject(File f) throws Exception{ InputStream is=new FileInputStream(f); //ObjectOutputStream 核心类 ObjectInputStream ois=new ObjectInputStream(is); return (User)ois.readObject(); }
publicstaticvoid main(String[] args) throws Exception{
/*****************将对象序列化***************/
/* User user=new User(); user.setUserId(1); user.setUserName("张艺谋"); user.setUserSex("男"); user.setUserAge(50); TestSerializable.writeObject(user); */
/*****************将对象序反列化***************/
User user=TestSerializable.readObject(new File("d:""user.tmp")); System.out.println(user); } } |
