How to represent the instance object of Student
Student s = new Student();.
The first way of expression
Actually telling us that any class has an implicit static member variable class
Class c1 = Student.class;
The second way of expression
It is already known that objects of this class pass the getClass method
Student s = new Student();
Class c2 = s.getClass();
The third way of expression
Class c3 = Class.forName("com.zhuoyue.test.Student");//Need to throw an exception
Demo.java
package com.zhuoyue.test;
public class Demo {
public static void main(String[] args) {
Student s = new Student();
Class c1 = Student.class;
System.out.println(c1);
Class c2 = s.getClass();
System.out.println(c2);
Class c3 = null;
try {
c3 = Class.forName("com.zhuoyue.test.Student");
System.out.println(c3);
} catch (ClassNotFoundException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
try {
Student s1 = (Student)c1.newInstance();
s1.say();
} catch (InstantiationException | IllegalAccessException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
try {
Student s2 = (Student)c2.newInstance();
s2.say();
} catch (InstantiationException | IllegalAccessException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
try {
Student s3 = (Student)c3.newInstance();
s3.say();
} catch (InstantiationException | IllegalAccessException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
Student.java
package com.zhuoyue.test;
public class Student {
public void say (){
System.out.println("student");
}
private int id = 1;
private String name = "hongzhe";
public int getId() {
return id;
}
public void setId(int id) {
this.id = id;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
@Override
public String toString() {
return "Student [id=" + id + ", name=" + name + "]";
}
}