BaseServlet

public void doPost(HttpServletRequest request, HttpServletResponse response)
   throws ServletException, IOException {

  try {
   /*获取方法名称*/
   String methodName = request.getParameter("method");
   
   /*获取当前对象的类型对象*/
   Class<?> classType = this.getClass();
   
//   System.out.println(classType);
   /*获取方法对象  1,方法名称.2,方法参数的类型*/
   Method method = classType.getDeclaredMethod(methodName, new Class[]{HttpServletRequest.class, HttpServletResponse.class});
   
   /*执行方法
    * this:调用哪个对象的方法
    * Object[]:参数*/
   method.invoke(this, new Object[]{request, response});
   
  } catch (Exception e) {
   System.out.println(e.getMessage());
   //response.sendRedirect("error.jsp");
   
  }
 }

import java.io.IOException;
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;
@WebServlet(urlPatterns="/BaseServlet")
public abstract class  BaseServlet extends HttpServlet {

	public void doGet(HttpServletRequest request, HttpServletResponse response)
			throws ServletException, IOException {
		doPost(request, response);
	}

	public void doPost(HttpServletRequest request, HttpServletResponse response)
			throws ServletException, IOException {
		try {
			String method=request.getParameter("method");
			//判断!如果没有来参数,就执行默认的方法
			if(method ==null){
				method="execute";
			}
			//this表示 *当前运行类
			Class clazz=this.getClass();
			//根据 指定的名称 获取执行的方法
			Method methods=clazz.getMethod(method, HttpServletRequest.class,HttpServletResponse.class);
			//执行
			methods.invoke(this, request,response);
		} catch (Exception e) {
			e.printStackTrace();
		}	
	}
	//子类必须实现的默认方法
	public abstract void execute(HttpServletRequest request,HttpServletResponse response);
}