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); } }