对象的拷贝目前我所能知道的只是一个属性一个属性的set比如

 A a =  new A();
 A b = new A();
 b.setXXX(a.getXXX)

不能用a=b这种方法，因为这样还是用同一个对象
一个一个的set才是两个相同对象

public class Person implements Cloneable{
/** 姓名 **/
private String name;

/** 电子邮件 **/
private Email email;

public String getName() {
    return name;
}

public void setName(String name) {
    this.name = name;
}

public Email getEmail() {
    return email;
}

public void setEmail(Email email) {
    this.email = email;
}

public Person(String name,Email email){
    this.name  = name;
    this.email = email;
}

public Person(String name){
    this.name = name;
}

protected Person clone() {
    Person person = null;
    try {
        person = (Person) super.clone();
    } catch (CloneNotSupportedException e) {
        e.printStackTrace();
    }

    return person;
}

}

public class Client {
public static void main(String[] args) {
//写封邮件
Email email = new Email("请参加会议","请与今天12:30到二会议室参加会议...");

    Person person1 =  new Person("张三",email);

    Person person2 =  person1.clone();
    person2.setName("李四");
    Person person3 =  person1.clone();
    person3.setName("王五");

    System.out.println(person1.getName() + "的邮件内容是：" + person1.getEmail().getContent());
    System.out.println(person2.getName() + "的邮件内容是：" + person2.getEmail().getContent());
    System.out.println(person3.getName() + "的邮件内容是：" + person3.getEmail().getContent());
}

}

Output:
张三的邮件内容是：请与今天12:30到二会议室参加会议...
李四的邮件内容是：请与今天12:30到二会议室参加会议...
王五的邮件内容是：请与今天12:30到二会议室参加会议...