Serialization and deserialization of java Analysis

Read article directory

First, what is the serialization and de-serialization
Second, serialization and de-serialization major role in
three prerequisites to achieve serialization and de-serialization
Fourth, how to implement serialization and de-serialization
V. code implementation
Precautions

First, what is the serialization and de-serialization

Java serialization (Serialization): to convert a java object sequence of bytes

java deserialization (Anti-Serialization): new java object by the sequence of bytes in memory process.

This byte sequence contains: type information of an object, the object data and object type data.

Second, the serialization and deserialization major role

1. Byte saved (persisted) to a hard disk, are generally written to a file;

2. The sequence of bytes transferred objects on the network;

Third, to achieve serialization and deserialization prerequisite

Object serialization of a class in order to succeed, two conditions must be met:

1. implement java.io.Serializable
all the attributes of the class 2 must be serializable. If a property is not serializable, the property must be marked transient ( transient ).

Fourth, how to implement serialization and de-serialization

ObjectInputStream ObjectOutputStream class and high-level data stream, which comprises a method and deserialize serialized objects.
1.ObjectOutputStream class: using writeObject (Object x) a method for serialization .

public final void writeObject(Object x) throws IOException

2.ObjectInputStream categories: using Object readObject () method deserialization .

public final Object readObject() throws IOException, ClassNotFoundException

Fifth, code implementation

Employees entity class (Employee.java)

 1 package com.cdh;
 2 
 3 /**
 4  * @author chudonghai
 5  * @editor
 6  * @date 2019年9月23日 下午2:16:27
 7  * @version v1.0
 8  * @since 1.0
 9  * @ClassName Employee
10  * @Description 雇员类
11  */
12 public class Employee implements java.io.Serializable
13 
14 {
15     /**
16      * generated serial version ID
17      */
18 is      Private  static  Final  Long serialVersionUID = -4308926516970571240L ;
 . 19  
20 is      public String name;
 21 is      public String address;
 22 is      public  transient  int an SSN;
 23 is      public  int Number;
 24  
25      / ** 
26 is       * Description: The purpose of this method is to write, purely for let class more complete and no other purpose. Do not tangled.
27       * * / 
28      public  void MailCheck () {
 29          System.out.println ( "Check to Mailing A" + name + "" + address);
 30      }
31 }

Serialization achieve Demo:

1  Package Penalty for com.cdh;
 2  / ** 
3  * @author chudonghai
 4  * @editor
 5  * @date 2019 Nian 9 23 afternoon 2:29:01
 6  * @version  
7  * @Since  
8  * @ClassName SerializationDemo
 9  * @Description serialization achieved Demo
 10  * / 
. 11  Import the java.io. * ;
 12 is  
13 is  public  class SerializationDemo
 14  {
 15     public  static  void main (String [] args)
 16     {
 . 17       Employee e = new Employee();
18       e.name = "chudonghai";
19       e.address = "beijing";
20       e.SSN = 999999999;
21       e.number = 101;
22       try
23       {
24          FileOutputStream fileOut =
25          new FileOutputStream("E://aaa//employee.ser");
26          ObjectOutputStream out = new ObjectOutputStream(fileOut);
27          out.writeObject(e);
28          out.close();
29          fileOut.close();
30          System.out.printf("Serialized data is saved in E:/aaa/employee.ser");
31       }catch(IOException i)
32       {
33           i.printStackTrace();
34       }
35    }
36 }

Deserialize achieve Demo:

1  Package Penalty for com.cdh;
 2  / ** 
3  * @author chudonghai
 4  * @editor 
 5  * @date 2019 Nian 9 23 afternoon 2:29:58
 6  * @version  
7  * @Since  
8  * @ClassName DeserializationDemo
 9  * @Description deserialized achieve Demo
 10  * / 
. 11  Import the java.io. * ;
 12 is  
13 is  public  class DeserializationDemo
 14  {
 15     public  static  void main (String [] args)
 16     {
17       Employee e = null;
18       try
19       {
20          FileInputStream fileIn = new FileInputStream("E://aaa//employee.ser");
21          ObjectInputStream in = new ObjectInputStream(fileIn);
22          e = (Employee) in.readObject();
23          in.close();
24          fileIn.close();
25       }catch(IOException i)
26       {
27          i.printStackTrace();
28          return;
29       }catch(ClassNotFoundException c)
30       {
31          System.out.println("Employee class not found");
32          c.printStackTrace();
33          return;
34       }
35       System.out.println("Deserialized Employee...");
36       System.out.println("Name: " + e.name);
37       System.out.println("Address: " + e.address);
38       System.out.println("SSN: " + e.SSN);
39       System.out.println("Number: " + e.number);
40     }
41 }

important point

DETAILED objects need to convert readObject used.

Deserialization, if the sequence of the previous generation can not find the file, it will be reported ClassNotFound.