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())));    }}