java序列化反序列化

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:

publicinterfaceSerializable {

}

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:

/**

*将对象序列化到磁盘文件中

*@paramo

*@throwsException

*/

publicstaticvoidwriteObject(Object o)throwsException{

File f=newFile("d:""user.tmp");

if(f.exists()){

f.delete();

}

FileOutputStream os=newFileOutputStream(f);

//ObjectOutputStream核心类

ObjectOutputStream oos=newObjectOutputStream(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:

/**

*反序列化,将磁盘文件转化为对象

*@paramf

*@return

*@throwsException

*/

publicstaticUser readObject(File f)throwsException{

InputStream is=newFileInputStream(f);

//ObjectOutputStream核心类

ObjectInputStream ois=newObjectInputStream(is);

return(User)ois.readObject();

}

贴出完整的demo

Java对象:

packagecom.io.bean;

importjava.io.Serializable;

publicclassUserimplementsSerializable{

privateintuserId;

privateStringuserName;

privateStringuserSex;

privateintuserAge;

publicintgetUserAge() {

returnuserAge;

}

publicvoidsetUserAge(intuserAge) {

this.userAge= userAge;

}

publicintgetUserId() {

returnuserId;

}

publicvoidsetUserId(intuserId) {

this.userId= userId;

}

publicString getUserName() {

returnuserName;

}

publicvoidsetUserName(String userName) {

this.userName= userName;

}

publicString getUserSex() {

returnuserSex;

}

publicvoidsetUserSex(String userSex) {

this.userSex= userSex;

}

@Override

publicString toString() {

returnthis.getUserId() +" "+this.getUserName() +" "

+this.getUserSex() +" "+this.getUserAge();

}

}

序列化与反序列化

packagecom.io.test;

importjava.io.File;

importjava.io.FileInputStream;

importjava.io.FileOutputStream;

importjava.io.InputStream;

importjava.io.ObjectInputStream;

importjava.io.ObjectOutputStream;

importcom.io.bean.User;

publicclassTestSerializable {

/**

*将对象序列化到磁盘文件中

*@paramo

*@throwsException

*/

publicstaticvoidwriteObject(Object o)throwsException{

File f=newFile("d:""user.tmp");

if(f.exists()){

f.delete();

}

FileOutputStream os=newFileOutputStream(f);

//ObjectOutputStream核心类

ObjectOutputStream oos=newObjectOutputStream(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

*/

publicstaticUser readObject(File f)throwsException{

InputStream is=newFileInputStream(f);

//ObjectOutputStream核心类

ObjectInputStream ois=newObjectInputStream(is);

return(User)ois.readObject();

}

publicstaticvoidmain(String[] args)throwsException{

/*****************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(newFile("d:""user.tmp"));

System.out.println(user);

}

}