<a href="javascript:void(0);" onclick="clearCart()" id="clear" class="clear">清空购物车</a>
//Cliquez pour effacer l'événement de panier sur la page cart.jsp
function clearCart(){ if(confirm("您是否要清空购物车?")){ location.href="${pageContext.request.contextPath }/product?method=clearCart"; } }
public void service(HttpServletRequest req, HttpServletResponse resp)throws ServletException, IOException { req.setCharacterEncoding("UTF-8"); try { //1.获得请求对象的method的名称 String methodName = req.getParameter("methodName"); //2.获得当前被访问的对象的字节码对象 Class clazz = this.getClass();//ProductServlet.class 或者 //3.获得当前字节码对象中的指定方法 Method method = clazz.getMethod(methodName, HttpServletRequest.class,HttpServletResponse.class); //4执行相应功能方法 method.invoke(this, req,resp); } catch (Exception e) { e.printStackTrace(); } }
//Effacer la méthode du panier
public void clearCart(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { HttpSession session = request.getSession(); session.removeAttribute("cart"); //跳转回cart.jsp response.sendRedirect(request.getContextPath()+"/cart.jsp"); }
我点击清空就报异常了
java.lang.NullPointerException at java.lang.Class.searchMethods(Class.java:2832) at java.lang.Class.getMethod0(Class.java:2856) at java.lang.Class.getMethod(Class.java:1668) at com.itheima.web.servlet.BaseServlet.service(BaseServlet.java:25) at javax.servlet.http.HttpServlet.service(HttpServlet.java:727) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:303) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208) at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208) at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:220) at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:122) at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:501) at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:170) at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:98) at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:950) at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:116) at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:408) at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1040) at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:607) at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:315) at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145) at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615) at java.lang.Thread.run(Thread.java:745)
<a href="javascript:void(0);" onclick="clearCart()" id="clear" class="clear">清空购物车</a>
//Cliquez pour effacer l'événement du panier sur la page cart.jsp
function clearCart(){ if(confirm("您是否要清空购物车?")){ location.href="${pageContext.request.contextPath }/product?method=clearCart"; } }
public void service(HttpServletRequest req, HttpServletResponse resp)throws ServletException, IOException { req.setCharacterEncoding("UTF-8"); try { //1.获得请求对象的method的名称 String methodName = req.getParameter("methodName"); //2.获得当前被访问的对象的字节码对象 Class clazz = this.getClass();//ProductServlet.class 或者 //3.获得当前字节码对象中的指定方法 Method method = clazz.getMethod(methodName, HttpServletRequest.class,HttpServletResponse.class); //4执行相应功能方法 method.invoke(this, req,resp); } catch (Exception e) { e.printStackTrace(); } }
//Effacer la méthode du panier
public void clearCart(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { HttpSession session = request.getSession(); session.removeAttribute("cart"); //跳转回cart.jsp response.sendRedirect(request.getContextPath()+"/cart.jsp"); }
我点击清空就报异常了
java.lang.NullPointerException at java.lang.Class.searchMethods(Class.java:2832) at java.lang.Class.getMethod0(Class.java:2856) at java.lang.Class.getMethod(Class.java:1668) at com.itheima.web.servlet.BaseServlet.service(BaseServlet.java:25) at javax.servlet.http.HttpServlet.service(HttpServlet.java:727) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:303) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208) at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208) at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:220) at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:122) at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:501) at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:170) at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:98) at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:950) at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:116) at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:408) at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1040) at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:607) at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:315) at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145) at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615) at java.lang.Thread.run(Thread.java:745)
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