java註解與反射之四種獲取class物件的方法,通過class物件獲取父類class物件
阿新 • • 發佈:2020-12-09
四種建立class物件的方法
- 先建立三個類,Person,Student,Teacher。其中Student和Teacher繼承Person類
class Person{
public String name;
public Person() {
}
public Person(String name) {
this.name = name;
}
@Override
public String toString() {
return "Person{" +
"name='" + name + '\'' +
'}';
}
}
class Student extends Person{
public Student(){
this.name = "學生";
}
}
class Teacher extends Person{
public Teacher(){
this.name= "老師";
}
}
- 四種獲取class物件的方法
public class Test03 {
public static void main(String[] args) throws ClassNotFoundException {
Person person = new Student();
System.out.println("這個人是:"+person.name);
//方式一:通過物件獲得
Class c1 = person.getClass();
System.out.println(c1);
System.out.println(c1. hashCode());
//方式二:forname獲取
Class c2 = Class.forName("com.lixv.reflection.Student");
System.out.println(c2);
System.out.println(c2.hashCode());
//方式三:通過類名.class獲取
Class c3 = Student.class;
System.out.println(c3);
System.out.println(c3.hashCode());
//方式四:基本內建型別的包裝類都有一個Type屬性
Class c4 = Integer.TYPE;
System.out.println(c4);
}
}
執行結果:
hashcode是同一個值,說明,獲取的是同一個物件
- 獲取class的父類class物件
//測試建立class類的建立方式有哪些
public class Test03 {
public static void main(String[] args) throws ClassNotFoundException {
Person person = new Student();
System.out.println("這個人是:"+person.name);
//方式一:通過物件獲得
Class c1 = person.getClass();
System.out.println(c1);
System.out.println(c1.hashCode());
//獲得父類class物件
Class c5 = c1.getSuperclass();
System.out.println(c5);
}
}
執行結果: