对类来说的，即一个类应该只负责一项职责。如类A负责两个不同的职责，职责1，职责2。当职责1需求变更而改变A时，可能造成职责2智行错误，所以要将类A的粒度分解为A1，A2
错误的应用实例
package org.example.demo0;
/**
* @description: 单一职责原则
* @author: abel.he
* @date: 2023-07-31
**/
public class SingleResponsibility {
public static void main(String[] args) {
Vehicle vehicle = new Vehicle();
vehicle.run("摩托车");
vehicle.run("汽车");
vehicle.run("飞机");
}
}
class Vehicle {
public void run(String vehicleName) {
System.out.println(vehicleName + "在公路上运行");
}
}
正确的实例
package org.example.demo0;
/**
* @description: 单一职责原则(正确)
* @author: abel.he
* @date: 2023-07-31
**/
public class SingleResponsibilityCorrect {
public static void main(String[] args) {
Vehicle1 vehicle1 = new Vehicle1();
vehicle1.run("小汽车");
Air air = new Air();
air.run("飞机");
}
}
/**
* 汽车工具类
*/
class Vehicle1 {
public void run(String vehicleName) {
System.out.println(vehicleName + "在地上跑");
}
}
class Air {
public void run(String airName) {
System.out.println(airName + "在天上飞");
}
}