package com.hy.servlet;

import java.io.IOException;

import java.lang.reflect.InvocationTargetException;

import java.lang.reflect.Method;

import javax.servlet.ServletException;

import javax.servlet.annotation.WebServlet;

import javax.servlet.http.HttpServlet;

import javax.servlet.http.HttpServletRequest;

import javax.servlet.http.HttpServletResponse;

import com.hy.utils.StringUtil;

@WebServlet("/cs")

public class CoreServlet extends HttpServlet {

    @Override

    protected void service(HttpServletRequest request, HttpServletResponse response)

            throws ServletException, IOException {

        String ac = request.getParameter("ac");

        System.out.println("======="+ac+"======");

        if (StringUtil.isEmpty(ac))

            ac = "index";

        // 获取当前类的所有方法

        Method[] methods = this.getClass().getDeclaredMethods();

        for (Method m : methods) {

            // 获取方法名称

            String methodName = m.getName();

            if (ac.equals(methodName)) {

                // 找到和ac同名的方法，那么通过反射技术调用它

                try {

                    m.invoke(this, request, response);

                    return;

                } catch (IllegalAccessException | IllegalArgumentException | InvocationTargetException e) {

                    e.printStackTrace();

                }

            }

        }

        throw new RuntimeException("ac值错误");

    }

    private void index(HttpServletRequest request, HttpServletResponse response) {

        System.out.println("aaaaaaaaaaa");

    }

}

package com.hy.utils;

public class StringUtil {

    //判断字符串是否为null或者""

    public static boolean isEmpty(String str){

        return str==null || "".equals(str);

    }

    public static boolean isNotEmpty(String str){

        return !isEmpty(str);

    }

}