Java序列化是指將Java對象裝換為二進制數據流，以便在網絡中傳輸、存儲或復制。實現序列化需要實現Serializable接口，常見的序列化方式包括Java原生序列化和第三方庫的序列化。

在Java的原生序列化中，使用ObjectOutputStream類將對象輸出為字節流，而使用ObjectInputStream類將字節流反序列化回對象。以下是一個Java原生序列化的示例：

import java.io.*;
public class SerializationExample {
public static void main(String[] args) throws IOException, ClassNotFoundException {
FileOutputStream fileOut = new FileOutputStream("employee.ser");
ObjectOutputStream out = new ObjectOutputStream(fileOut);
Employee employee = new Employee("Tom", "Manager", 10000);
out.writeObject(employee);
out.close();
fileOut.close();
FileInputStream fileIn = new FileInputStream("employee.ser");
ObjectInputStream in = new ObjectInputStream(fileIn);
Employee employee2 = (Employee) in.readObject();
in.close();
fileIn.close();
System.out.println("Name: " + employee2.name);
System.out.println("Title: " + employee2.title);
System.out.println("Salary: " + employee2.salary);
}
}
class Employee implements Serializable {
String name;
String title;
transient int salary;
public Employee(String name, String title, int salary) {
this.name = name;
this.title = title;
this.salary = salary;
}
}

除了Java原生序列化，還有一些第三方庫可以用來實現序列化，例如Google的Protocol Buffer和Apache的Avro。這些庫一般都使用更加高效的序列化算法，同時可以提供跨語言支持。