Java 编程中的标记接口。
java 8object oriented programmingprogramming
Java 中的空接口称为标记接口，即它不包含任何方法或字段。通过实现这些接口，类将表现出与所实现接口相关的特殊行为。java.lang.Cloneable 和 java.io.Serializable 就是标记接口的示例。
示例 1
考虑以下示例，这里有一个名为 Student 的类，它实现了标记接口 Cloneable。在 main 方法中，我们尝试创建 Student 类的一个对象，并使用 clone() 方法对其进行克隆。
import java.util.Scanner;
public class Student implements Cloneable {
int age;
String name;
public Student (String name, int age){
this.age = age;
this.name = name;
}
public void display() {
System.out.println("Name of the student is: "+name);
System.out.println("Age of the student is: "+age);
}
public static void main (String args[]) throws CloneNotSupportedException {
Scanner sc = new Scanner(System.in);
System.out.println("Enter your name: ");
String name = sc.next();
System.out.println("Enter your age: ");
int age = sc.nextInt();
Student obj = new Student(name, age);
Student obj2 = (Student) obj.clone();
obj2.display();
}
}
输出
Enter your name: Krishna Enter your age: 29 Name of the student is: Krishna Age of the student is: 29
示例2
在以下 Java 程序中，Student 类有两个实例变量 name 和 age，其中 age 声明为瞬态变量。在另一个名为 ExampleSerialize 的类中，我们尝试序列化和反序列化 Student 对象，并显示其实例变量。由于 age 被声明为不可见(瞬态)，因此仅显示 name-value 变量。
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.io.Serializable;
class Student implements Serializable{
private String name;
private transient int age;
public Student(String name, int age){
this.name = name;
this.age = age;
}
public String getName() {
return this.name;
}
public void setName(String name) {
this.name = name;
}
public void setAge(int age) {
this.age = age;
}
public int getAge() {
return this.age;
}
}
public class ExampleSerialize {
public static void main(String args[]) throws Exception{
Student std1 = new Student("Krishna", 30);
FileOutputStream fos = new FileOutputStream("e:\student.ser");
ObjectOutputStream oos = new ObjectOutputStream(fos);
oos.writeObject(std1);
FileInputStream fis = new FileInputStream("e:\student.ser");
ObjectInputStream ois = new ObjectInputStream(fis);
Student std2 = (Student) ois.readObject();
System.out.println(std2.getName());
}
}
输出
Krishna
