设计模式-原型模式

Author: dolyw

DesignPattern/src/main/java/com/design/prototype/Location.java

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+package com.design.prototype;
+
+/**
+ * 地址
+ *
+ * @author wliduo[i@dolyw.com]
+ * @date 2023/2/1 17:32
+ */
+public class Location implements Cloneable {
+
+    private StringBuffer address;
+    private String remark;
+
+    public Location(StringBuffer address, String remark) {
+        this.address = address;
+        this.remark = remark;
+    }
+
+    @Override
+    protected Object clone() throws CloneNotSupportedException {
+        // String基础属性可以不用处理，但是StringBuffer等引用对象需要处理
+        Location location = (Location) super.clone();
+        location.setAddress(new StringBuffer(address));
+        return location;
+    }
+
+    @Override
+    public String toString() {
+        return "Location{" +
+                "address=" + address +
+                ", remark='" + remark + '\'' +
+                '}';
+    }
+
+    public StringBuffer getAddress() {
+        return address;
+    }
+
+    public void setAddress(StringBuffer address) {
+        this.address = address;
+    }
+
+    public String getRemark() {
+        return remark;
+    }
+
+    public void setRemark(String remark) {
+        this.remark = remark;
+    }
+}

DesignPattern/src/main/java/com/design/prototype/Main.java

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+package com.design.prototype;
+
+/**
+ * 原型模式 - 克隆，拷贝
+ *
+ * @author wliduo[i@dolyw.com]
+ * @date 2023/2/1 17:32
+ */
+public class Main {
+
+    public static void main(String[] args) throws Exception {
+        StringBuffer address = new StringBuffer("深圳市南山区XXX");
+        Location location = new Location(address, "XXX村");
+        Person wangMing = new Person("李明", 20, location);
+        // 克隆wangMing
+        Person liMing = (Person) wangMing.clone();
+        // 修改原始对象
+        wangMing.setName("王明");
+        wangMing.setAge(30);
+        address.reverse();
+        location.setRemark("XXX路");
+        // 输出原始和克隆对象，正常应该是深拷贝
+        // 修改原始对象，克隆对象还是刚开始声明的属性
+        // 将Person重写的clone方法对Location的克隆注释放开
+        // 以及Location重写的clone方法对StringBuffer的克隆注释放开
+        // 不然就会出现浅拷贝的问题
+        System.out.println(wangMing);
+        System.out.println(liMing);
+    }
+
+}

DesignPattern/src/main/java/com/design/prototype/Person.java

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+package com.design.prototype;
+
+/**
+ * 人，姓名，年龄，地址
+ *
+ * @author wliduo[i@dolyw.com]
+ * @date 2023/2/1 17:32
+ */
+public class Person implements Cloneable {
+
+    private String name;
+    private int age;
+    private Location location;
+
+    public Person(String name, int age, Location location) {
+        this.name = name;
+        this.age = age;
+        this.location = location;
+    }
+
+    @Override
+    protected Object clone() throws CloneNotSupportedException {
+        Person person = (Person) super.clone();
+        // 基础属性String及int可以不用处理
+        // 内置引用不重新进行克隆是浅拷贝，会导致指向同一个Location
+        // 必须针对内部引用再次进行克隆，这样才是深拷贝
+        person.setLocation((Location) location.clone());
+        return person;
+    }
+
+    @Override
+    public String toString() {
+        return "Person{" +
+                "name='" + name + '\'' +
+                ", age=" + age +
+                ", location=" + location +
+                '}';
+    }
+
+    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 Location getLocation() {
+        return location;
+    }
+
+    public void setLocation(Location location) {
+        this.location = location;
+    }
+}