- pythond的序列化: pickle 模块
- python 的pickle模块实现了基本的数据序列和反序列化。
- 通过pickle模块的序列化操作我们能够将程序中运行的对象信息保存到文件中去,永久存储。
- 通过pickle模块的反序列化操作,我们能够从文件中创建上一次程序保存的对象。
SerializeDemo.py
import pickle
class Employee:
def __init__(self):
name = None
address = None
SSN = None
number = None
def mailCheck(self):
{
print("Mailing a check to" + self.name + " " + self.address)
}
def set_name(self,name):
self.name = name
def set_address(self,address):
self.address = address
def set_number(self,number):
self.number = number
def set_SSN(self,SSN):
self.SSN = SSN
e = Employee()
e.set_name("Reyan Ali")
e.set_address("Phokka Kuan, Ambehta Peer")
e.set_number(101)
e.set_SSN(11122333)
print(e)
print(e.name)
print(e.address)
print(e.number)
print(e.SSN)
output = open('/tmp/data.pkl','wb')
pickle.dump(e,output)
output.close()
运行效果
用python 写反序列化操作:
import pickle
from SerializeDemo import Employee
pkl_file = open("/tmp/data.pkl",'rb')
data1 = pickle.load(pkl_file)
e = data1
print(e.name)
print(e.address)
print(e.number)
print(e.SSN)
e.mailCheck()
pkl_file.close()
2. Java 序列化
java 提供了一种对象序列化的机制,该机制中,一个对象可以被表示为一个字节序列,该字节序列包括该对象的数据、有关对象的类型的信息和存储在对象中数据的类型。
将 序列化 对象写入文件之后,可以从文件中读取出来,并且对它进行反序列化,也就是说,对象的类型信息、对象的数据,还有对象中的数据类型可以用来在内存中新建对象。
ObjectOutputStream 类用来序列化一个对象,如下的 SerializeDemo 例子实例化了一个 Employee 对象,并将该对象序列化到一个文件中。
该程序执行后,就创建了一个名为 employee.ser 文件。该程序没有任何输出,但是你可以通过代码研读来理解程序的作用。
注意: 当序列化一个对象到文件时, 按照 Java 的标准约定是给文件一个 .ser 扩展名。
// Employee.java
public class Employee implements java.io.Serializable
{
public String name;
public String address;
public transient int SSN ;
public int number;
public void mailCheck()
{
System.out.println("Mailing a check to " + name + " " + address);
}
}
//SerializeDemo.java
import java.io.*;
public class SerializeDemo
{
public static void main(String [] args)
{
Employee e = new Employee();
e.name = "Reyan Ali";
e.address = "Phokka Kuan, Ambehta Peer";
e.SSN = 11122333;
e.number = 101;
try
{
FileOutputStream fileOut = new FileOutputStream("/tmp/employee.ser");
ObjectOutputStream out = new ObjectOutputStream(fileOut);
out.writeObject(e);
out.close();
fileOut.close();
System.out.printf("Serialized data is saved in /tmp/employee.ser");
}catch(IO Exception i)
{
i.printStackTrace();
}
}
}
DeserializeDemo.java
import java.io.*;
public class DeserializeDemo
{
public static void main(String[] args)
{
Employee e = null;
try
{
FileInputStream fileIn = new FileInputStream("/tmp/employee.ser");
ObjectInputStream in = new Object InputStream (fileIn);
e = (Employee) in.readObject();
in.close();
fileIn.close();
}catch(IOException i)
{
i.printStackTrace();
return;
}catch(ClassNotFoundException c)
{
System.out.println("Employee class not found");
c.printStackTrace();
return;
}
System.out.println("Deserialized Employee...");
System.out.println("Name: " + e.name);
System.out.println("Address" + e.address);
System.out.println("SSN: " + e.SSN);
System.out.println("Number: "+e.number);
}
}