Single responsibility principle

Principle of single responsibility

Definition

Principle of single responsibility （SRP）, In terms of a class , There should be only one cause for it to change .

Simply speaking , Let a class do only part of the work , This reduces the coupling , Improve reusability , Improve readability , Reduce the risk caused by changes .

【 Common code 】

package pers.keafmd.accumulate.designmode.singleresponsibility;/** * Keafmd * * @ClassName: FreshmenSelected * @Description:  New students  * @author:  Cowherd Conan  * @date: 2022-06-27 19:39 */public class FreshmenSelected {    public void distributeBooks(){        System.out.println(" Distribute books ...");    }    public void allocateDormitory(){        System.out.println(" Assign dormitories ...");    }    public static void main(String[] args) {        System.out.println(" Start arranging for new students ：");        FreshmenSelected freshmenSelected = new FreshmenSelected();        freshmenSelected.distributeBooks();        freshmenSelected.allocateDormitory();        System.out.println(" end-of-job ！");    }}

effect ：

 Start arranging for new students ： Distribute books ... Assign dormitories ... end-of-job ！Process finished with exit code 0

【 Principle of single responsibility 】

StudyMembers

package pers.keafmd.accumulate.designmode.singleresponsibility;/** * Keafmd * * @ClassName: StudyMembers * @Description:  Study commissar  * @author:  Cowherd Conan  * @date: 2022-06-27 19:46 */public class StudyMembers {    public void distributeBooks(){        System.out.println(" The study committee is responsible for ： Distribute books ...");    }}

LifeCommittee

package pers.keafmd.accumulate.designmode.singleresponsibility;/** * Keafmd * * @ClassName: LifeCommittee * @Description:  Life Commissioner  * @author:  Cowherd Conan  * @date: 2022-06-27 19:47 */public class LifeCommittee {    public void allocateDormitory(){        System.out.println(" The life committee is responsible for ： Assign dormitories ...");    }}

ClassMonitor

package pers.keafmd.accumulate.designmode.singleresponsibility;/** * Keafmd * * @ClassName: ClassMonitor * @Description:  Monitor of the class  * @author:  Cowherd Conan  * @date: 2022-06-27 19:46 */public class ClassMonitor {    private StudyMembers studyMembers;    private LifeCommittee lifeCommittee;    public ClassMonitor() {        studyMembers = new StudyMembers();        lifeCommittee = new LifeCommittee();    }    public void assignWork(){        System.out.println(" The monitor began to assign jobs to different class cadres , Work together to complete the enrollment of new students ：");        studyMembers.distributeBooks();        lifeCommittee.allocateDormitory();        System.out.println(" end-of-job ！");    }    public static void main(String[] args) {        System.out.println(" Start arranging for new students ：");        ClassMonitor classMonitor = new ClassMonitor();        classMonitor.assignWork();    }}

effect ：

 Start arranging for new students ： The monitor began to assign jobs to different class cadres , Work together to complete the enrollment of new students ： The study committee is responsible for ： Distribute books ... The life committee is responsible for ： Assign dormitories ... end-of-job ！Process finished with exit code 0