原型模式-蒲公英云

原型模式：用原型实例指定创建指定对象的种类，并且通过复制这些原型创建新的对象，同时又能保证性能。这种模式是实现了一个原型接口，该接口用于创建当前对象的克隆。当直接创建对象的代价比较大时，则采用这种模式。

注意：如果字段是值类型的，则对该字段执行逐位复制，如果字段是引用类型，则复制引用但是不复制引用的对象，因此，原始对象及其复本引用同一对象。

潜复制：被复制对象的所有变量都含有原来的对象相同的值，而所有的对其他对象的引用仍然指向原来的对象。

深复制：把引用对象的变量指向复制过来的新对象，而不是原有的被引用的对象；

潜复制实例UML图

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深复制实例UML图：

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潜复制代码：

/**
 * @author Shuyu.Wang
 * @package:com.shuyu.prototype
 * @description:
 * @date 2018-11-16 23:11
 **/
@Data
public class WorkExperience {
    private String workDate;
    private String company;
}
/**
 * @author Shuyu.Wang
 * @package:com.shuyu.prototype
 * @description:原型类,实现Cloneable，重写clone(),实现浅复制
 * @date 2018-11-16 23:05
 **/
@Slf4j
public class Resume implements Cloneable{
    private String name;
    private String sex;
    private String age;
    private WorkExperience workExperience;
    public Resume(String name){
        this.name=name;
        workExperience=new WorkExperience();
    }
    public void setPersonInfo(String sex,String age){
        this.sex=sex;
        this.age=age;
    }
    public void setWorkExperience(String workDate,String company){
        workExperience.setWorkDate(workDate);
        workExperience.setCompany(company);
    }
    public void show(){
        log.info("name="+name,",sex="+sex,",age="+age);
        log.info("company="+workExperience.getCompany(),"workDate="+workExperience.getWorkDate());
    }
    @Override
    public Object clone() {
        Object clone = null;
        try {
            clone = super.clone();
        } catch (CloneNotSupportedException e) {
            e.printStackTrace();
        }
        return clone;
    }
}

深复制代码：

/**
 * @author Shuyu.Wang
 * @package:com.shuyu.prototype
 * @description:
 * @date 2018-11-16 23:11
 **/
@Data
public class WorkExperience2 implements Cloneable{
    private String workDate;
    private String company;
    @Override
    public Object clone() {
        Object clone = null;
        try {
            clone = super.clone();
        } catch (CloneNotSupportedException e) {
            e.printStackTrace();
        }
        return clone;
    }
}
/**
 * @author Shuyu.Wang
 * @package:com.shuyu.prototype
 * @description:原型类,实现Cloneable，重写clone(),实现深复制
 * @date 2018-11-16 23:05
 **/
@Slf4j
public class Resume2 implements Cloneable{
    private String name;
    private String sex;
    private String age;
    private WorkExperience2 workExperience;
    public Resume2(String name){
        this.name=name;
        workExperience=new WorkExperience2();
    }
    public void setPersonInfo(String sex,String age){
        this.sex=sex;
        this.age=age;
    }
    public void setWorkExperience(String workDate,String company){
        workExperience.setWorkDate(workDate);
        workExperience.setCompany(company);
    }
    public void show(){
        log.info("name="+name,",sex="+sex,",age="+age);
        log.info("company="+workExperience.getCompany(),"workDate="+workExperience.getWorkDate());
    }
    @Override
    public Object clone() {
        Resume2 clone = null;
        try {
            clone = (Resume2)super.clone();
            clone.workExperience=(WorkExperience2) workExperience.clone();
        } catch (CloneNotSupportedException e) {
            e.printStackTrace();
        }
        return clone;
    }
}

测试代码：

@RunWith(SpringRunner.class)
@SpringBootTest
public class PrototypeApplicationTests {
    @Test
    public void clone1() {
        Resume resume=new Resume("测试1");
        resume.setPersonInfo("男","25");
        resume.setWorkExperience("2016-2017","台达");
        Resume resume1=(Resume)resume.clone();
        resume1.setWorkExperience("2017-2018","百度");
        Resume resume2=(Resume)resume.clone();
        resume2.setWorkExperience("2018-2019","阿里");
        resume.show();
        resume1.show();
        resume2.show();
    }
    @Test
    public void clone2() {
        Resume2 resume=new Resume2("测试1");
        resume.setPersonInfo("男","25");
        resume.setWorkExperience("2016-2017","台达");
        Resume2 resume1=(Resume2)resume.clone();
        resume1.setWorkExperience("2017-2018","百度");
        Resume2 resume2=(Resume2)resume.clone();
        resume2.setWorkExperience("2018-2019","阿里");
        resume.show();
        resume1.show();
        resume2.show();
    }
}

运行结果如下：

2018-11-16 23:40:51.859 INFO 44132 —- [ main] com.shuyu.prototype.Resume : name=测试1
2018-11-16 23:40:51.859 INFO 44132 —- [ main] com.shuyu.prototype.Resume : company=阿里
2018-11-16 23:40:51.859 INFO 44132 —- [ main] com.shuyu.prototype.Resume : name=测试1
2018-11-16 23:40:51.859 INFO 44132 —- [ main] com.shuyu.prototype.Resume : company=阿里
2018-11-16 23:40:51.859 INFO 44132 —- [ main] com.shuyu.prototype.Resume : name=测试1
2018-11-16 23:40:51.859 INFO 44132 —- [ main] com.shuyu.prototype.Resume : company=阿里

代码github地址：https://github.com/iot-wangshuyu/designpatterns/tree/master/prototype