【GOF23设计模式】_备忘录模式_多点备忘_事务操作_回滚数据底层架构JAVA253

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一、S03E253_01【GOF23设计模式】_备忘录模式、多点备忘、事务操作、回滚数据底层架构

package com.test.memento;/** * 源发器类 */public class Emp {    private String ename;    private int age;    private double salary;    //进行备忘操作，并返回备忘录对象    public EmpMemento memento(){        return new EmpMemento(this);    }    //进行数据恢复，恢复成制定备忘录对象的值    public void recovery(EmpMemento mmt){        this.ename = mmt.getEname();        this.age = mmt.getAge();        this.salary = mmt.getSalary();    }    public Emp(String ename, int age, double salary) {        super();        this.ename = ename;        this.age = age;        this.salary = salary;    }    public String getEname() {        return ename;    }    public void setEname(String ename) {        this.ename = ename;    }    public int getAge() {        return age;    }    public void setAge(int age) {        this.age = age;    }    public double getSalary() {        return salary;    }    public void setSalary(double salary) {        this.salary = salary;    }}

package com.test.memento;/** * 备忘录类 */public class EmpMemento {    private String ename;    private int age;    private double salary;    public EmpMemento(Emp e){        this.ename = e.getEname();        this.age = e.getAge();        this.salary = e.getSalary();    }    public String getEname() {        return ename;    }    public void setEname(String ename) {        this.ename = ename;    }    public int getAge() {        return age;    }    public void setAge(int age) {        this.age = age;    }    public double getSalary() {        return salary;    }    public void setSalary(double salary) {        this.salary = salary;    }}

package com.test.memento;import java.util.ArrayList;/** * 负责人类 */public class CareTaker {    private EmpMemento memento;//  private List<EmpMemento> list = new ArrayList<EmpMemento>();    public EmpMemento getMemento() {        return memento;    }    public void setMemento(EmpMemento memento) {        this.memento = memento;    }}

package com.test.memento;public class Client {    public static void main(String[] args) {        CareTaker careTaker = new CareTaker();        Emp emp = new Emp("小高", 18, 900);        System.out.println("第一次打印对象："+emp.getEname()+"--"                +emp.getAge()+"--"+emp.getSalary());        careTaker.setMemento(emp.memento());//备忘一次        emp.setAge(38);        emp.setEname("小搞");        emp.setSalary(9000);        System.out.println("第二次打印对象："+emp.getEname()+"--"                +emp.getAge()+"--"+emp.getSalary());        emp.recovery(careTaker.getMemento());//恢复到备忘录对象保存的状态        System.out.println("第三次打印对象："+emp.getEname()+"--"                +emp.getAge()+"--"+emp.getSalary());    }}

控制台输出：第一次打印对象：小高--18--900.0第二次打印对象：小搞--38--9000.0第三次打印对象：小高--18--900.0