构造型模式
Builder(生成器)模式
Factory Method(工厂方法)模式
意图：用于创建对象的接口，同时控制对哪个类进行实例化。
Abstract Factory(抽象工厂)模式
意图：创建一系列相互关联或相互依赖的对象。
Prototype(原型)模式
prototype模式不通过实例化类来创建一个新的未初始化的实例，而是通过复制一个现有对象来生成新的对象。
浅拷贝
public class PackageInfo implements Cloneable { private Long id; private String receiverName; private String receiverAddress; private String senderName; private String senderPhoneNo; //other fields, getters, setters and other methods... public Long getId() { return id; } public void setId(Long id) { this.id = id; } public String getReceiverName() { return receiverName; } public void setReceiverName(String receiverName) { this.receiverName = receiverName; } public String getReceiverAddress() { return receiverAddress; } public void setReceiverAddress(String receiverAddress) { this.receiverAddress = receiverAddress; } public String getSenderName() { return senderName; } public void setSenderName(String senderName) { this.senderName = senderName; } public String getSenderPhoneNo() { return senderPhoneNo; } public void setSenderPhoneNo(String senderPhoneNo) { this.senderPhoneNo = senderPhoneNo; } public PackageInfo clone() { try { return (PackageInfo)super.clone(); } catch (CloneNotSupportedException e) { System.out.println("Cloning not allowed."); return null; } } public static PackageInfo clonePackage(String userName) { //load package as prototype data from db... PackageInfo prototype = loadPackageInfo(userName); //clone information... prototype = prototype.clone(); //initialize copied data... prototype.setId(null); return prototype; } //Simulate loading data from database private static PackageInfo loadPackageInfo(String userName) { PackageInfo packageInfo = new PackageInfo(); //create a String object in jvm heap not jvm string pool packageInfo.setId(100l); packageInfo.setReceiverName("John"); packageInfo.setReceiverAddress("People Square,Shanghai"); packageInfo.setSenderName("William"); packageInfo.setSenderPhoneNo("12345678901"); return packageInfo; }}public class PackageInfoTestDrive { public static void main(String[] args) { PackageInfo currentInfo = PackageInfo.clonePackage("John"); System.out.println("Original package information:"); display(currentInfo); currentInfo.setId(10000l); currentInfo.setReceiverName("Ryan"); currentInfo.setReceiverAddress("People Square, Shanghai"); System.out.println("\nNew package information:"); display(currentInfo); } private static void display(PackageInfo currentInfo) { System.out.println("Package id: " + currentInfo.getId()); System.out.println("Receiver name: " + currentInfo.getReceiverName()); System.out.println("Receiver address: " + currentInfo.getReceiverAddress()); System.out.println("Sender name: " + currentInfo.getSenderName()); System.out.println("Sender Phone No.: " + currentInfo.getSenderPhoneNo()); }}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 DeepCopyBean implements Serializable { private String objectField; private int primitiveField; public String getObjectField() { return objectField; } public void setObjectField(String objectField) { this.objectField = objectField; } public int getPrimitiveField() { return primitiveField; } public void setPrimitiveField(int primitiveField) { this.primitiveField = primitiveField; } public DeepCopyBean deepCopy() { try { ByteArrayOutputStream buf = new ByteArrayOutputStream(); ObjectOutputStream o = new ObjectOutputStream(buf); o.writeObject(this); ObjectInputStream in = new ObjectInputStream(new ByteArrayInputStream(buf.toByteArray())); return (DeepCopyBean) in.readObject(); } catch (IOException e) { e.printStackTrace(); } catch (ClassNotFoundException e) { e.printStackTrace(); } return null; }}public class DeepCopyBeanTestDrive { public static void main(String[] args) { DeepCopyBean originalBean = new DeepCopyBean(); //create a String object in jvm heap not jvm string pool originalBean.setObjectField(new String("123456")); originalBean.setPrimitiveField(2); //clone this bean DeepCopyBean newBean = originalBean.deepCopy(); System.out.println("Primitive ==? " + (newBean.getPrimitiveField() == originalBean.getPrimitiveField())); System.out.println("Object ==? " + (newBean.getObjectField() == originalBean.getObjectField())); System.out.println("Object equal? " + (newBean.getObjectField().equals(originalBean.getObjectField()))); }}