package cn.haoju.reflections;import java.lang.reflect.Method;import java.util.ArrayList;public class ReflectionDemo {    public static void main(String[] args) throws Exception {        ArrayList<Integer> arrayList = new ArrayList<Integer>();        arrayList.add(3);        //arrayList.add("lihao"); //编译不通过        Class listClass = arrayList.getClass();        Method method = listClass.getDeclaredMethod("add", Object.class);        method.invoke(arrayList, "lisan");                System.out.println(arrayList); //[3, lisan]    }}