Java中有 基本数据类型（元类型），和 类的实例对象 这个引用数据类型。而一般使用 『 = 』号做赋值操作的时候。对于基本数据类型，实际上是拷贝的它的值，但是对于对象而言，其实赋值的只是这个对象的引用，将原对象的引用传递过去，他们实际上还是指向的同一个对象。

浅拷贝：

只对类中基本数据类型进行了拷贝，而对引用数据类型只是进行了引用的传递，而没有真实的创建一个新的对象，则认为是浅拷贝。

package copy;
/*** @Author Snail* @Describe 浅拷贝* @CreateTime 2019/6/23*/
public class ShallowCopy {public static void main(String[] args) throws CloneNotSupportedException {Student student1 = new Student();student1.setAge(29);student1.setTeacher(new Teacher());//利用clone（）方法创建一个新的对象，实现了一次浅拷贝Student student2= (Student) student1.clone();System.out.println("student1::"+student1);System.out.println("student2::"+student2);//其对象（teacher）的地址空间是一样的，是浅拷贝的特征System.out.println("student1.getTeacher()::"+student1.getTeacher());System.out.println("student2.getTeacher()::"+student2.getTeacher());
//        student1::copy.Student@66a29884
//        student2::copy.Student@4769b07b
//        student1.getTeacher()::copy.Teacher@cc34f4d
//        student2.getTeacher()::copy.Teacher@cc34f4d}
}class Teacher {private String name;private int age;public String getName() {return name;}public void setName(String name) {this.name = name;}public int getAge() {return age;}public void setAge(int age) {this.age = age;}
}class Student implements Cloneable{private int age;private Teacher teacher;public int getAge() {return age;}public void setAge(int age) {this.age = age;}public Teacher getTeacher() {return teacher;}public void setTeacher(Teacher teacher) {this.teacher = teacher;}@Overrideprotected Object clone() throws CloneNotSupportedException {return super.clone();}}

深拷贝：

在对类中引用数据类型（类的实例对象）进行拷贝的时候，创建了一个新的对象，并且复制其内的成员变量，则认为是深拷贝

package copy;
/*** @Author Snail* @Describe 深拷贝* @CreateTime 2019/6/23*/
public class DeepCopy {public static void main(String[] args) throws CloneNotSupportedException {Student student1 = new Student();student1.setAge(29);student1.setTeacher(new Teacher());Student student2= (Student) student1.clone();System.out.println("student1::"+student1);System.out.println("student2::"+student2);//深拷贝，其引用数据类型地址空间不一致System.out.println("student1.getTeacher()::"+student1.getTeacher());System.out.println("student2.getTeacher()::"+student2.getTeacher());
//        student1::copy.Student@66a29884
//        student2::copy.Student@4769b07b
//        student1.getTeacher()::copy.Teacher@cc34f4d
//        student2.getTeacher()::copy.Teacher@17a7cec2}
}class Teacher implements Cloneable{private String name;private int age;public String getName() {return name;}public void setName(String name) {this.name = name;}public int getAge() {return age;}public void setAge(int age) {this.age = age;}@Overrideprotected Object clone() throws CloneNotSupportedException {return super.clone();}
}class Student implements Cloneable{private int age;private Teacher teacher;public int getAge() {return age;}public void setAge(int age) {this.age = age;}public Teacher getTeacher() {return teacher;}public void setTeacher(Teacher teacher) {this.teacher = teacher;}@Overrideprotected Object clone() throws CloneNotSupportedException {//深拷贝Student student=(Student) super.clone();//拷贝引用数据类型student.teacher= (Teacher) this.teacher.clone();return student;}}

总结：

浅拷贝和深拷贝是相对的，如果一个对象内部只有基本数据类型，那用 clone() 方法获取到的就是这个对象的深拷贝，而如果其内部还有引用数据类型，那用 clone() 方法就是一次浅拷贝的操作。