java获取nosuchmethod异常
这是我的密码
package first_project;
import java.lang.reflect.*;
import java.util.Scanner;
public class My_Class {
public static void main(String[] args)throws Exception {
Scanner sc=new Scanner(System.in);
//Getting numbers from user
System.out.println("Enter First Number:");
int a=sc.nextInt();
System.out.println("Enter Second Number:");
int b=sc.nextInt();
//code for private method
Class c=addition.class;
Method m = addition.class.getDeclaredMethod("add(a,b)");
m.setAccessible(true);
m.invoke(c);
}
}
package first_project;
//Class for addition
public class addition{
private void add(int a,int b)
{
int ans= a+ b;
System.out.println("addition:"+ans);
}
}
这是个例外:
Exception in thread "main" java.lang.NoSuchMethodException: first_project.addition.add(int a,int b)()
at java.base/java.lang.Class.getDeclaredMethod(Class.java:2434)
at first_project.My_Class.main(My_Class.java:15)
# 1 楼答案
更改此行:
为此:
getDeclaredMethod
将方法名及其参数类型作为参数要调用该方法,请执行以下操作:
# 2 楼答案
^{} 接受方法名和参数类型作为参数。你必须这样改变它
Method m = addition.class.getDeclaredMethod("add", int.class, int.class);
方法调用也是错误的:
应该是:
相应地替换
*instance of addition*
等此外,Java还使用了一些code conventions之类的用法:类名必须以大写字母开头,等等