创建型模式-原型模式

　　有的对象比较复杂，创建消耗较大，可以用一个对象原型不断复制出其它对象

　　有三种方式

　　浅拷贝

package creational.pattern.prototype.shallowclone; public class Prototype implements Cloneable{ public Prototype clone(){ Prototype prototype = null; try{ prototype = (Prototype)super.clone(); }catch(CloneNotSupportedException e){ e.printStackTrace(); } return prototype; } } package creational.pattern.prototype.shallowclone; public class ConcretePrototype extends Prototype { public void show() { System.out.println("原型模式实现类"); } }

　　测试代码

package creational.pattern.prototype.shallowclone; public class Client { public static void main(String[] args) { ConcretePrototype cp = new ConcretePrototype(); for(int i=0; i< 10; i++) { ConcretePrototype clonecp = (ConcretePrototype)cp.clone(); clonecp.show(); System.out.println(clonecp); } } }

　　运行结果

　　浅拷贝的问题在对于对象属性，克隆出的对象和原对象的对象属性是同一个

　　深拷贝

package creational.pattern.prototype.deepclone; import java.util.ArrayList; public class Prototype implements Cloneable { private ArrayList list = new ArrayList(); public Prototype clone(){ Prototype prototype = null; try{ prototype = (Prototype)super.clone(); prototype.list = (ArrayList) this.list.clone(); }catch(CloneNotSupportedException e){ e.printStackTrace(); } return prototype; } } package creational.pattern.prototype.deepclone; public class ConcretePrototype extends Prototype { public void show() { System.out.println("原型模式实现类"); } }

　　测试代码

package creational.pattern.prototype.deepclone; public class Client { public static void main(String[] args) { ConcretePrototype cp = new ConcretePrototype(); for(int i=0; i< 10; i++) { ConcretePrototype clonecp = (ConcretePrototype)cp.clone(); clonecp.show(); System.out.println(clonecp); } } }

　　运行结果

　　深拷贝在于将对类中的对象属性也进行了克隆，上面两个要实现Cloneabl接口

　　序列化

package creational.pattern.prototype.serilizable; import java.io.Serializable; public class SerializableObject implements Serializable { private static final long serialVersionUID = -6071344933545997422L; } package creational.pattern.prototype.serilizable; import java.io.ByteArrayInputStream; import java.io.ByteArrayOutputStream; import java.io.IOException; import java.io.ObjectInputStream; import java.io.ObjectOutputStream; import java.io.Serializable; public class Prototpye implements Serializable, Cloneable { private static final long serialVersionUID = -1045333494067611913L; // String类型，可以clone拷贝 private String string; // 引用类型，无法clone拷贝 private SerializableObject obj; //浅复制.利用Object的clone（）方法 public Object clone()throws CloneNotSupportedException { Prototpye proto=(Prototpye)super.clone(); return proto; } //要实现深复制，需要采用流的形式读入当前对象的二进制输入，再写出二进制数据对应的对象。 public Object deepClone()throws IOException ,ClassNotFoundException{ ByteArrayOutputStream bos=new ByteArrayOutputStream(); ObjectOutputStream oos=new ObjectOutputStream(bos); oos.writeObject(this); ByteArrayInputStream bis=new ByteArrayInputStream(bos.toByteArray()); ObjectInputStream ois=new ObjectInputStream(bis); return ois.readObject(); } public String getString() { return string; } public void setString(String str) { this.string=str; } public SerializableObject getObj() { return obj; } }

　　上面有浅拷贝和序列化两种方法实现，要实现序列化，必须实现Serializable接口

转载于:https://www.cnblogs.com/liunianfeiyu/p/10093039.html