强配置获取方法没有问题呀，求求大哥大姐们告诉一下吧，孩子卡住好几天了！！！

Question

package web;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.lang.reflect.Method;

public abstract class BaseServlet extends HttpServlet {
    @Override
    public void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
      doPost(req,resp);
    }

    @Override
    protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        String action = req.getParameter("action");
        try {
            // 获取action业务鉴别字符串，获取相应的业务 方法反射现象
            Method method =  this.getClass().getDeclaredMethod(action,HttpServletRequest.class,HttpServletResponse.class);
            //调用目标业务  方法
            method.setAccessible(true);
            method.invoke(this,req,resp);
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}

 java.lang.NoSuchMethodException: web.BookServlet.(javax.servlet.http.HttpServletRequest,javax.servlet.http.HttpServletResponse)
    at java.base/java.lang.Class.getDeclaredMethod(Class.java:2633)
    at web.BaseServlet.doPost(BaseServlet.java:21)
    at web.BaseServlet.doGet(BaseServlet.java:13)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:635)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:742)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:231)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
    at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
    at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:198)
    at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:96)
    at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:496)
    at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:140)
    at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:81)
    at org.apache.catalina.valves.AbstractAccessLogValve.invoke(AbstractAccessLogValve.java:650)
    at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:87)
    at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:342)
    at org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:803)
    at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:66)
    at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:790)
    at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1459)
    at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49)
    at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1130)
    at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:630)
    at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
    at java.base/java.lang.Thread.run(Thread.java:832)

Answer 1

 

String action = req.getParameter("action"); 

你文中这个action的值web.BookServlet 在BaseServlet 中并没有定义啊，当然会有问题啊