JAVA之路_假克隆、浅克隆、深克隆

标签：java   对象   类   

Java中，对于基本类型，可以用“=”进行克隆，而对于引用类型却不能简单的使用“=”进行克隆，这与JAVA的内存使用空间有关，JAVA在栈中保存基本类型和引用变量，在堆中保存对象。对于引用变量而言，使用“=”将修改引用，而不是复制堆中的对象，此时两个引用对象将指向同一个对象，因此如果对一个变量修改则会修改另一个对象。

public class Employee {
    private String name;
    private int age;
//省略get和set方法
@Override
    public String toString() {
        return "姓名：" + name + ", 年龄：" + age;
    }
}
  public class Test {
    public static void main(String[] args) {
        System.out.println("克隆之前：");
        Employee employee1 = new Employee();
        employee1.setName("芋头1");
        employee1.setAge(12);
        System.out.println("员工1的信息：");
        System.out.println(employee1);
        System.out.println("克隆之后：");
        Employee employee2 = employee1;
        employee2.setName("芋头2");
        employee2.setAge(114);
        System.out.println("员工2的信息：");
        System.out.println(employee2);
        System.out.println("员工1的信息：");
        System.out.println(employee1);
    }
}

 public class Address {
    private String state;
    private String province;
    private String city;
//省略get和set
 @Override
    public String toString() {
        StringBuilder sb = new StringBuilder();
        sb.append("国家：" + state + ", ");
        sb.append("省：" + province + ", ");
        sb.append("市：" + city);
        return sb.toString();
    }
}

public class Employee implements Cloneable {
    private String name;
    private int age;
    private Address address;
//省略get和set
@Override
    public String toString() {
        StringBuilder sb = new StringBuilder();
        sb.append("姓名：" + name + ", ");
        sb.append("年龄：" + age + "\n");
        sb.append("地址：" + address);
        return sb.toString();
    }
    
    @Override
    public Employee clone() {
        Employee employee = null;
        try {
            employee = (Employee) super.clone();
        } catch (CloneNotSupportedException e) {
            e.printStackTrace();
        }
        return employee;
    }
}

public class Test {
    public static void main(String[] args) {
        System.out.println("克隆之前：");
        Address address = new Address("中国", "吉林", "长春");
        Employee employee1 = new Employee("明日科技", 12, address);
        System.out.println("员工1的信息：");
        System.out.println(employee1);
        System.out.println("克隆之后：");
        Employee employee2 = employee1.clone();
        employee2.getAddress().setState("中国");
        employee2.getAddress().setProvince("四川");
        employee2.getAddress().setCity("成都");
        employee2.setName("西南交通大学");
        employee2.setAge(114);
        System.out.println("员工2的信息：");
        System.out.println(employee2);
        System.out.println("员工1的信息：");
        System.out.println(employee1);
    }
}

在Adress类中增加

protected Address clone() {
        Address address = null;
        try {
            address = (Address) super.clone();
        } catch (CloneNotSupportedException e) {
            e.printStackTrace();
        }
        return address;
    }

 public Employee clone() {
        Employee employee = null;
        try {
            employee = (Employee) super.clone();
            employee.address = address.clone();
        } catch (CloneNotSupportedException e) {
            e.printStackTrace();
        }

JAVA之路_假克隆、浅克隆、深克隆

标签：java   对象   类   

原文地址：http://blog.csdn.net/chaoshenyutou/article/details/41848251