Question

写一个关于反射的联系，运行的时候报java.lang.ClassNotFoundException: Methods错误！求解

package edu.sisv.struts2.helloWorld.reflect;

import java.lang.reflect.*;
public class Methods {

private int f1(Object p, int x) throws NullPointerException {
if (p == null)
throw new NullPointerException();
return x;
}

public static void main(String args[]) {

Class cls=null;
try {
cls = Class.forName("Methods");
} catch (ClassNotFoundException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
Method methlist[] = cls.getDeclaredMethods();
for (int i = 0; i < methlist.length; i++) {
Method m = methlist[i];
System.out.println("name = " + m.getName());
System.out.println("decl class = " + m.getDeclaringClass());
Class pvec[] = m.getParameterTypes();
for (int j = 0; j < pvec.length; j++)
System.out.println("param #" + j + " " + pvec[j]);
Class evec[] = m.getExceptionTypes();
for (int j = 0; j < evec.length; j++)
System.out.println("exc #" + j + " " + evec[j]);
System.out.println("return type = " + m.getReturnType());
System.out.println("-----");
}
}
}

Answer 1

Class.forName的参数没有输入全，应该是包名+类名

Answer 2

cls = Class.forName("edu.sisv.struts2.helloWorld.reflect.Methods");

包名+类名，否则找不到，就异常了
java.lang.ClassNotFoundException: Methods