深入探究Java原型模式的魅力

public class Shape implements Cloneable { private String id; private String type; public void draw() { System.out.println("Shape: " + type + ", id: " + id); } public String getId() { return id; } public void setId(String id) { this.id = id; } public String getType() { return type; } public void setType(String type) { this.type = type; } public Object clone() { Object clone = null; try { clone = super.clone(); } catch (CloneNotSupportedException e) { e.printStackTrace(); } return clone; } } public class Rectangle extends Shape { public Rectangle() { setType("Rectangle"); } public void draw() { System.out.println("Inside Rectangle::draw() method."); } } public class Square extends Shape { public Square() { setType("Square"); } public void draw() { System.out.println("Inside Square::draw() method."); } } public class ShapeCache { private static Map shapeMap = new HashMap<>(); public static Shape getShape(String shapeId) { Shape cachedShape = shapeMap.get(shapeId); return (Shape) cachedShape.clone(); } public static void loadCache() { Rectangle rectangle = new Rectangle(); rectangle.setId("1"); shapeMap.put(rectangle.getId(), rectangle); Square square = new Square(); square.setId("2"); shapeMap.put(square.getId(), square); } } public class PrototypePatternDemo { public static void main(String[] args) { ShapeCache.loadCache(); Shape clonedShape = ShapeCache.getShape("1"); System.out.println("Shape : " + clonedShape.getType()); Shape clonedShape2 = ShapeCache.getShape("2"); System.out.println("Shape : " + clonedShape2.getType()); } } 

import java.io.*; public class Person implements Serializable, Cloneable { private String name; private int age; private Address address; public Person(String name, int age, Address address) { this.name = name; this.age = age; this.address = address; } @Override public Person clone() { try { Person clone = (Person) super.clone(); clone.address = address.clone(); return clone; } catch (CloneNotSupportedException e) { throw new RuntimeException(e); } } private static class Address implements Serializable, Cloneable { private String city; private String street; public Address(String city, String street) { this.city = city; this.street = street; } @Override public Address clone() { try { return (Address) super.clone(); } catch (CloneNotSupportedException e) { throw new RuntimeException(e); } } } public static void main(String[] args) { Address address = new Address("New York", "5th Avenue"); Person person1 = new Person("John", 30, address); Person person2 = person1.clone(); person2.setName("Jane"); person2.setAge(25); person2.getAddress().setCity("Los Angeles"); person2.getAddress().setStreet("Beverly Hills"); System.out.println(person1); System.out.println(person2); } // Getters and setters public String getName() { return name; } public void setName(String name) { this.name = name; } public int getAge() { return age; } public void setAge(int age) { this.age = age; } public Address getAddress() { return address; } public void setAddress(Address address) { this.address = address; } @Override public String toString() { return "Person{" + "name='" + name + '\'' + ", age=" + age + ", address=" + address + '}'; } }