Java筆試試題如何實現對象克隆?

引導語:在java面向對象的編程當中，要複製引用類型的對象，就必須克隆這些對象。以下是本站小編分享給大家的Java筆試試題如何實現對象克隆?，歡迎參考學習!

　如何實現對象克隆?

答：有兩種方式：

1). 實現Cloneable接口並重寫Object類中的clone()方法;

2). 實現Serializable接口，通過對象的序列化和反序列化實現克隆，可以實現真正的深度克隆，代碼如下。

123456789101112131415161718192021222324 import ArrayInputStream;import ArrayOutputStream;import ctInputStream;import ctOutputStream;public class MyUtil {private MyUtil() {throw new AssertionError();}public static <T> T clone(T obj) throws Exception {ByteArrayOutputStream bout = new ByteArrayOutputStream();ObjectOutputStream oos = new ObjectOutputStream(bout);eObject(obj);ByteArrayInputStream bin = new ByteArrayInputStream(teArray());ObjectInputStream ois = new ObjectInputStream(bin);return (T) Object();// 説明：調用ByteArrayInputStream或ByteArrayOutputStream對象的close方法沒有任何意義// 這兩個基於內存的流只要垃圾回收器清理對象就能夠釋放資源，這一點不同於對外部資源（如文件流）的釋放}}

下面是測試代碼：

1234567891011121314151617181920212223242526272829303132333435363738394041424344454647484950 import alizable;/*** 人類* @author 駱昊**/class Person implements Serializable {private static final long serialVersionUID = -9102017020286042305L;private String name; // 姓名private int age; // 年齡private Car car; // 座駕public Person(String name, int age, Car car) {this = name;this = age;this = car;}public String getName() {return name;}public void setName(String name) {this = name;}public int getAge() {return age;}public void setAge(int age) {this = age;}public Car getCar() {return car;}public void setCar(Car car) {this = car;}@Overridepublic String toString() {return "Person [name=" + name + ", age=" + age + ", car=" + car + "]";}}

1234567891011121314151617181920212223242526272829303132333435363738 /*** 小汽車類* @author 駱昊**/class Car implements Serializable {private static final long serialVersionUID = -5713945027627603702L;private String brand; // 品牌private int maxSpeed; // 最高時速public Car(String brand, int maxSpeed) {thisd = brand;thispeed = maxSpeed;}public String getBrand() {return brand;}public void setBrand(String brand) {thisd = brand;}public int getMaxSpeed() {return maxSpeed;}public void setMaxSpeed(int maxSpeed) {thispeed = maxSpeed;}@Overridepublic String toString() {return "Car [brand=" + brand + ", maxSpeed=" + maxSpeed + "]";}}

12345678910111213141516 class CloneTest {public static void main(String[] args) {try {Person p1 = new Person("Hao LUO", 33, new Car("Benz", 300));Person p2 = e(p1); // 深度克隆ar()rand("BYD");// 修改克隆的'Person對象p2關聯的汽車對象的品牌屬性// 原來的Person對象p1關聯的汽車不會受到任何影響// 因為在克隆Person對象時其關聯的汽車對象也被克隆了tln(p1);} catch (Exception e) {tStackTrace();}}}