1.Java对象复制概念
1.1 浅复制（浅克隆）
复制的对象的所有变量与含有与原来的对象相同的值，而所有的对其他对象的引用仍然指向原对象。换言之，浅复制仅仅复制所考虑的对象，而不复制它所引用的对象。
1.2 深复制（深度克隆）
复制的对象的所有变量都含有与原来的对象相同的值，除去那些引用其他对象的变量。那些引用其他对象的变量将指向复制的新对象，而不是原来的对象。换言之，深复制把要复制的对象所引用的对象都复制了一遍。
2.Java对象的clone()克隆方法
2.1 clone方法
clone方法将对象复制了一份并返回给调用者。一般而言，clone()方法满足
- 对任何的对象x，都有x.clone() != x;也即克隆的对象与原对象不是同一个对象，他们有不同的内存地址
- 对任何的对象x，都有x.clone().getClass() == x.getClass()，也即克隆对象与原对象的类型一致。
- 如果对象x的equals()方法定义恰当，那么x.clone().equal(x)应该成立。
2.2 Java中对象的克隆
- 为了获取对象的一份拷贝，我们可以利用Object的clone()方法
- 在派生类中覆盖基类的clone()方法，并声明为public
- 在派生类的clone()方法中，调用super.clone()。
- 在派生类中实现Cloneable接口
2.3 示例
2.3.1 浅复制示例
package org.wem.im;/** * ** Title: Person
* Copyright: Copyright (c) 2016 * Company: * * ** Description: 测试Java对象浅克隆 *
* * @version v1.0.0 * @author kucs * @date 2016年9月30日下午2:28:22 * * Modification History: *---------------------------------------------------------* * */public class Person implements Cloneable { class Worker{ private String workName; private String department; public String getWorkName() { return workName; } public void setWorkName(String workName) { this.workName = workName; } public String getDepartment() { return department; } public void setDepartment(String department) { this.department = department; } @Override public String toString() { return "Worker [workName=" + workName + ", department=" + department + "]"; } } private String name; private String age; private String weight; private String height; private Worker worker; public String getName() { return name; } public void setName(String name) { this.name = name; } public String getAge() { return age; } public void setAge(String age) { this.age = age; } public String getWeight() { return weight; } public void setWeight(String weight) { this.weight = weight; } public String getHeight() { return height; } public void setHeight(String height) { this.height = height; } public Worker getWorker() { return worker; } public void setWorker(Worker worker) { this.worker = worker; } @Override protected Object clone() throws CloneNotSupportedException { // TODO Auto-generated method stub return super.clone(); } @Override public String toString() { return "Person [name=" + name + ", age=" + age + ", weight=" + weight + ", height=" + height + ", worker=" + worker + "]"; } public static void main(String[] args) throws CloneNotSupportedException { Person p = new Person(); Worker worker = p.new Worker(); worker.setWorkName("asiainfo"); worker.setDepartment("cboss"); p.setWorker(worker); p.setName("kucs"); p.setAge("24"); p.setWeight("65"); p.setHeight("170"); Person p_clone = (Person) p.clone(); System.out.println("原对象信息："+p.toString()); System.out.println("克隆对象信息："+p_clone.toString()); //修改p_clone对象的值 p_clone.setName("kucs_clone"); //修改对象引用的对象的值 worker.setWorkName("asianinfo_clone"); System.out.println("修改后的克隆对象信息："+p_clone.toString()); System.out.println("原对象信息："+p.toString()); if(p.getWorker().getWorkName().equals(p_clone.getWorker().getWorkName())){ System.out.println("浅复制对象，其引用的对象未复制"); }else{ System.out.println("非浅复制对象，其引用的对象也复制"); } }}
运行结果
原对象信息：Person [name=kucs, age=24, weight=65, height=170, worker=Worker [workName=asiainfo, department=cboss]]克隆对象信息：Person [name=kucs, age=24, weight=65, height=170, worker=Worker [workName=asiainfo, department=cboss]]修改后的克隆对象信息：Person [name=kucs_clone, age=24, weight=65, height=170, worker=Worker [workName=asianinfo_clone, department=cboss]]原对象信息：Person [name=kucs, age=24, weight=65, height=170, worker=Worker [workName=asianinfo_clone, department=cboss]]浅复制对象，其引用的对象未复制
结果说明：浅克隆之后的对象与原对象不是同一个对象。修改其中一个对象的值对另一个对象没有影响。
浅克隆中其引用的对象未复制，还是指向同一个对象。
2.3.2 深复制示例
对浅复制示例代码做了调整
package org.wem.im;/** * ** Title: Person
* Copyright: Copyright (c) 2016 * Company: * * ** Description: 测试Java对象深度克隆 *
* * @version v1.0.0 * @author kucs * @date 2016年9月30日下午2:45:22 * * Modification History: *---------------------------------------------------------* * */public class Person implements Cloneable { class Worker implements Cloneable{ private String workName; private String department; public String getWorkName() { return workName; } public void setWorkName(String workName) { this.workName = workName; } public String getDepartment() { return department; } public void setDepartment(String department) { this.department = department; } @Override protected Object clone() throws CloneNotSupportedException { // TODO Auto-generated method stub return super.clone(); } @Override public String toString() { return "Worker [workName=" + workName + ", department=" + department + "]"; } } private String name; private String age; private String weight; private String height; private Worker worker; public String getName() { return name; } public void setName(String name) { this.name = name; } public String getAge() { return age; } public void setAge(String age) { this.age = age; } public String getWeight() { return weight; } public void setWeight(String weight) { this.weight = weight; } public String getHeight() { return height; } public void setHeight(String height) { this.height = height; } public Worker getWorker() { return worker; } public void setWorker(Worker worker) { this.worker = worker; } @Override protected Object clone() throws CloneNotSupportedException { // TODO Auto-generated method stub Person p = (Person) super.clone(); p.worker = (Worker) worker.clone(); return p; } @Override public String toString() { return "Person [name=" + name + ", age=" + age + ", weight=" + weight + ", height=" + height + ", worker=" + worker + "]"; } public static void main(String[] args) throws CloneNotSupportedException { Person p = new Person(); Worker worker = p.new Worker(); worker.setWorkName("asiainfo"); worker.setDepartment("cboss"); p.setWorker(worker); p.setName("kucs"); p.setAge("24"); p.setWeight("65"); p.setHeight("170"); Person p_clone = (Person) p.clone(); System.out.println("原对象信息："+p.toString()); System.out.println("克隆对象信息："+p_clone.toString()); //修改p_clone对象的值 p_clone.setName("kucs_clone"); //修改对象引用的对象的值 worker.setWorkName("asianinfo_clone"); System.out.println("修改后的克隆对象信息："+p_clone.toString()); System.out.println("原对象信息："+p.toString()); if(p.getWorker().getWorkName().equals(p_clone.getWorker().getWorkName())){ System.out.println("浅复制对象，其引用的对象未复制"); }else{ System.out.println("非浅复制对象，其引用的对象也复制"); } }}
运行结果：
原对象信息：Person [name=kucs, age=24, weight=65, height=170, worker=Worker [workName=asiainfo, department=cboss]]克隆对象信息：Person [name=kucs, age=24, weight=65, height=170, worker=Worker [workName=asiainfo, department=cboss]]修改后的克隆对象信息：Person [name=kucs_clone, age=24, weight=65, height=170, worker=Worker [workName=asiainfo, department=cboss]]原对象信息：Person [name=kucs, age=24, weight=65, height=170, worker=Worker [workName=asianinfo_clone, department=cboss]]非浅复制对象，其引用的对象也复制
结果说明：深克隆中，对克隆后的对象修改值，不影响原对象的值。修改克隆后的对象引用的值，对原对象引用的对象也没有影响。
3.利用串行化来做深复制
这主要是为了避免重写比较复杂的深复制clone()方法。把对象写到流里的过程是串行化过程（Serialization），把对象从流中读取出来是并行化（Deserialization）过程。
注意：写在流里的对象时一个拷贝，而原对象仍然存在jvm中，因此串行化过程只是一个对象的拷贝。
在Java语言中，深复制一个对象，常常可以先使用对象实现Serializable接口，然后把对象写到一个流里，再从流里读取出来，便可以重建对象。
package org.wem.im;import java.io.ByteArrayInputStream;import java.io.ByteArrayOutputStream;import java.io.IOException;import java.io.ObjectInputStream;import java.io.ObjectOutputStream;import java.io.Serializable;/** * ** Title: Person
* Copyright: Copyright (c) 2016 * Company: * * ** Description: 测试Java对象克隆 *
* * @version v1.0.0 * @author kucs * @date 2016年9月30日下午2:28:22 * * Modification History: *---------------------------------------------------------* * */public class Person implements Serializable { class Worker implements Serializable{ private String workName; private String department; public String getWorkName() { return workName; } public void setWorkName(String workName) { this.workName = workName; } public String getDepartment() { return department; } public void setDepartment(String department) { this.department = department; } @Override public String toString() { return "Worker [workName=" + workName + ", department=" + department + "]"; } } private String name; private String age; private String weight; private String height; private Worker worker; public String getName() { return name; } public void setName(String name) { this.name = name; } public String getAge() { return age; } public void setAge(String age) { this.age = age; } public String getWeight() { return weight; } public void setWeight(String weight) { this.weight = weight; } public String getHeight() { return height; } public void setHeight(String height) { this.height = height; } public Worker getWorker() { return worker; } public void setWorker(Worker worker) { this.worker = worker; } public Object deepClone() throws IOException, ClassNotFoundException{ //将对象写到流 ByteArrayOutputStream bo = new ByteArrayOutputStream(); ObjectOutputStream oo = new ObjectOutputStream(bo); oo.writeObject(this); //从流里读取处理啊 ByteArrayInputStream bi = new ByteArrayInputStream(bo.toByteArray()); ObjectInputStream oi = new ObjectInputStream(bi); return oi.readObject(); } @Override public String toString() { return "Person [name=" + name + ", age=" + age + ", weight=" + weight + ", height=" + height + ", worker=" + worker + "]"; } public static void main(String[] args) throws CloneNotSupportedException, ClassNotFoundException, IOException { Person p = new Person(); Worker worker = p.new Worker(); worker.setWorkName("asiainfo"); worker.setDepartment("cboss"); p.setWorker(worker); p.setName("kucs"); p.setAge("24"); p.setWeight("65"); p.setHeight("170"); Person p_clone = (Person) p.deepClone(); System.out.println("原对象信息："+p.toString()); System.out.println("克隆对象信息："+p_clone.toString()); //修改p_clone对象的值 p_clone.setName("kucs_clone"); //修改对象引用的对象的值 worker.setWorkName("asianinfo_clone"); System.out.println("修改后的克隆对象信息："+p_clone.toString()); System.out.println("原对象信息："+p.toString()); if(p.getWorker().getWorkName().equals(p_clone.getWorker().getWorkName())){ System.out.println("浅复制对象，其引用的对象未复制"); }else{ System.out.println("非浅复制对象，其引用的对象也复制"); } }}
运行结果
原对象信息：Person [name=kucs, age=24, weight=65, height=170, worker=Worker [workName=asiainfo, department=cboss]]克隆对象信息：Person [name=kucs, age=24, weight=65, height=170, worker=Worker [workName=asiainfo, department=cboss]]修改后的克隆对象信息：Person [name=kucs_clone, age=24, weight=65, height=170, worker=Worker [workName=asiainfo, department=cboss]]原对象信息：Person [name=kucs, age=24, weight=65, height=170, worker=Worker [workName=asianinfo_clone, department=cboss]]非浅复制对象，其引用的对象也复制