BaseServlet

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

  try {
   /*獲取方法名稱*/
   String methodName = request.getParameter("method");
   
   /*獲取當前對象的類型對象*/
   Class<?> classType = this.getClass();
   
//   System.out.println(classType);
   /*獲取方法對象  1,方法名稱.2,方法參數的類型*/
   Method method = classType.getDeclaredMethod(methodName, new Class[]{HttpServletRequest.class, HttpServletResponse.class});
   
   /*執行方法
    * this:調用哪個對象的方法
    * Object[]:參數*/
   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");
			//判斷!如果沒有來參數,就執行默認的方法
			if(method ==null){
				method="execute";
			}
			//this表示 *當前運行類
			Class clazz=this.getClass();
			//根據 指定的名稱 獲取執行的方法
			Method methods=clazz.getMethod(method, HttpServletRequest.class,HttpServletResponse.class);
			//執行
			methods.invoke(this, request,response);
		} catch (Exception e) {
			e.printStackTrace();
		}	
	}
	//子類必須實現的默認方法
	public abstract void execute(HttpServletRequest request,HttpServletResponse response);
}