原型模式

2019-11-06 07:23:49

字体：大中小

来源：转载

供稿：网友

参考《设计模式的艺术软件开发人员内功修炼之道》-刘伟著

实验目的

原型模式作为创建对象方式的一种，新对象为原型对象的拷贝；分为浅拷贝和深拷贝

实验代码

package PRototypeManager;import java.io.ByteArrayInputStream;import java.io.ByteArrayOutputStream;import java.io.IOException;import java.io.ObjectInputStream;import java.io.ObjectOutputStream;import java.io.Serializable;import java.util.HashMap;abstract class ShallowCopyAttachment implements Cloneable { private String name; private ShallowCopyAttachment subAttach; public void setName(String name) { this.name = name; } String getName() { return this.name; } public void setAttachment(ShallowCopyAttachment attach) { subAttach = attach; } public ShallowCopyAttachment getAttachment() { return subAttach; } @Override public ShallowCopyAttachment clone() { // TODO Auto-generated method stub Object scAttch = null; try { scAttch = super.clone(); return (ShallowCopyAttachment) (scAttch); } catch (CloneNotSupportedException e) { e.printStackTrace(); return null; } }}class ShallowCopyAttachmentA extends ShallowCopyAttachment { public ShallowCopyAttachmentA(){ this.setName("ShallowCopyAttachmentA"); }}abstract class DeepCopyAttachment implements Serializable { private String name; private DeepCopyAttachment subAttach; public void setName(String name) { this.name = name; } String getName() { return this.name; } public void setAttachment(DeepCopyAttachment attach) { subAttach = attach; } public DeepCopyAttachment getAttachment() { return subAttach; } /** * */ private static final long serialVersionUID = -1025197199068560319L; /** * */ //private static final long serialVersionUID = 1L; public DeepCopyAttachment deepClone() throws IOException, ClassNotFoundException { ByteArrayOutputStream bao = new ByteArrayOutputStream(); ObjectOutputStream oos = new ObjectOutputStream(bao); oos.writeObject(this); ByteArrayInputStream bis = new ByteArrayInputStream(bao.toByteArray()); ObjectInputStream ois = new ObjectInputStream(bis); return (DeepCopyAttachment)ois.readObject(); }}class DeepCopyAttachmentA extends DeepCopyAttachment { /** * */ private static final long serialVersionUID = -4458940275684875744L; public DeepCopyAttachmentA(){ this.setName("DeepCopyAttachmentA"); }}class AttachmentManager { private HashMap<String, ShallowCopyAttachment> scHashMap; private HashMap<String, DeepCopyAttachment> dcHashMap; private AttachmentManager() { scHashMap = new HashMap<String, ShallowCopyAttachment>(); dcHashMap = new HashMap<String, DeepCopyAttachment>(); } static class ManagerBuilder { static final AttachmentManager attach = new AttachmentManager(); } public static AttachmentManager getAttachmentManager() { return ManagerBuilder.attach; } public void addShallowCopyAttachment(String key, ShallowCopyAttachment scAttach) { scHashMap.put(key, scAttach); } public ShallowCopyAttachment getShallowCopyAttachment(String key) { return ((ShallowCopyAttachment) (scHashMap.get(key))).clone(); } public void addDeepCopyAttachment(String key, DeepCopyAttachment dcAttach) { dcHashMap.put(key, dcAttach); } public DeepCopyAttachment getDeepCopyAttachment(String key) { try { DeepCopyAttachment a = ((DeepCopyAttachment) (dcHashMap.get(key))).deepClone(); //System.out.println(a.getName() + ":" + a.getAttachment()); return a; } catch (ClassNotFoundException e) { // TODO Auto-generated catch block e.printStackTrace(); } catch (IOException e) { // TODO Auto-generated catch block e.printStackTrace(); } return null; }}public class CloneTest { public static void main(String[] args) { // TODO Auto-generated method stub AttachmentManager attach = AttachmentManager.getAttachmentManager(); ShallowCopyAttachment scAttach = new ShallowCopyAttachmentA(); ShallowCopyAttachment subSCAttach = new ShallowCopyAttachmentA(); subSCAttach.setAttachment(null); scAttach.setAttachment(subSCAttach); DeepCopyAttachment dcAttach = new DeepCopyAttachmentA(); DeepCopyAttachment subDCAttach = new DeepCopyAttachmentA(); subDCAttach.setAttachment(null); dcAttach.setAttachment(subDCAttach); attach.addShallowCopyAttachment("scAttach", scAttach); attach.addDeepCopyAttachment("dcAttach", dcAttach); ShallowCopyAttachment scAttach1 = attach.getShallowCopyAttachment("scAttach"); DeepCopyAttachment dcAttach1 = attach.getDeepCopyAttachment("dcAttach"); System.out.println("dcAttach1 = " + dcAttach1); System.out.println(scAttach.getName() + " ; " + scAttach.getAttachment()); System.out.println(scAttach1.getName() + " ; " + scAttach1.getAttachment()); System.out.println(scAttach == scAttach1); System.out.println(scAttach.getAttachment() == scAttach1.getAttachment()); System.out.println(dcAttach.getName() + " ; " + dcAttach.getAttachment()); System.out.println(dcAttach1.getName() + " ; " + dcAttach1.getAttachment()); System.out.println(dcAttach == dcAttach1); System.out.println(dcAttach.getAttachment() == dcAttach1.getAttachment()); }}

结果输出

dcAttach1 = PrototypeManager.DeepCopyAttachmentA@4eec7777ShallowCopyAttachmentA ; PrototypeManager.ShallowCopyAttachmentA@3b07d329ShallowCopyAttachmentA ; PrototypeManager.ShallowCopyAttachmentA@3b07d329falsetrueDeepCopyAttachmentA ; PrototypeManager.DeepCopyAttachmentA@28d93b30DeepCopyAttachmentA ; PrototypeManager.DeepCopyAttachmentA@41629346falsefalse