Small Example Description:
A) implement a JSP is responsible for the foreground display, the servlet is responsible for background processing of interactive small instances
b) The JSP page gets a start number, an ending number, and a multiplication table for the servlet print response from the form.
Unresolved issues:
A) Jump seemingly does not recognize the directory of HTML files, so I copied the source code into the JSP, the results can be found.
b) After the servlet gets the data from the JSP, if you want to out.print the relevant JS code on the JSP page does not seem to be implemented
The current effect is: Pop-up JS alert () Popup on the current servlet page
Redirect back to the previous JSP page.
Source:
<%@ page language= "java" contenttype= "text/html; Charset=utf-8 "pageencoding= "UTF-8"%><! DOCTYPE HTML PUBLIC "-//w3c//dtd HTML 4.01 transitional//en" "Http://www.w3.org/TR/html4/loose.dtd" >H1{margin:0Auto; Text-Align:center;} H3{margin:0Auto; Text-Align:center; Margin-bottom:40px;} . Contair{margin:0Auto; Background-Color:yellow; width:400px; padding:20px 40px;}</style><body><%Boolean Islarger=false; Boolean IsError=false; Islarger= (Boolean) request.getattribute ("Larger"); if(islarger!=NULL){ if(islarger==true) {out.println ("<Script>"); String message= "The initial number is greater than the ending number!" "; Out.println ("Alert ('" +message+ "')"); Out.println ("</Script>"); }} IsError= (Boolean) request.getattribute ("Error"); if(iserror!=NULL){ if(iserror==true) {out.println ("<Script>"); String message= "The input is wrong!" "; Out.println ("Alert ('" +message+ "')"); Out.println ("</Script>"); } } %>class= "Contair" > Initial Number:<input type= "text" name= "Begin" ><br>End Number:<input type= "text" name= "End" ><br> PackageFirstservlet;Importjava.io.IOException;ImportJava.io.PrintWriter;ImportJavax.servlet.RequestDispatcher;Importjavax.servlet.ServletException;ImportJavax.servlet.annotation.WebServlet;ImportJavax.servlet.http.HttpServlet;Importjavax.servlet.http.HttpServletRequest;ImportJavax.servlet.http.HttpServletResponse;ImportOrg.apache.jasper.tagplugins.jstl.core.Out; @WebServlet ("/fs") Public classFsextendsHttpServlet {Private Static Final LongSerialversionuid = 1L; String message; /** * @seeHttpservlet#httpservlet ()*/ PublicFS () {Super(); Message= "HelloWorld"; //TODO auto-generated Constructor stub } /** * @seeHttpservlet#doget (httpservletrequest request, httpservletresponse response)*/ protected voidDoget (HttpServletRequest request, httpservletresponse response)throwsservletexception, IOException {//TODO auto-generated Method StubDoPost (request, response); } /** * @seeHttpservlet#dopost (httpservletrequest request, httpservletresponse response)*/ protected voidDoPost (HttpServletRequest request, httpservletresponse response)throwsservletexception, IOException {//TODO auto-generated Method StubResponse.setcontenttype ("Text/html;charset=utf-8"); PrintWriter out=Response.getwriter (); String Start=request.getparameter ("Begin"); String End=request.getparameter ("End"); Try { intsn=Integer.parseint (Start); inten=Integer.parseint (END); if(sn>EN) { BooleanIslarger=true; Request.setattribute ("Larger", Islarger); Request.getrequestdispatcher ("Servletcom.jsp"). Forward (request, response); } Else{Request.setattribute ("SN", SN); Request.setattribute ("EN", EN); RequestDispatcher Dispatcher=request.getrequestdispatcher ("Result"); Dispatcher.forward (request, response); } } Catch(Exception e) {//Todo:handle Exception BooleanIserror=true; Request.setattribute ("Error", IsError); Request.getrequestdispatcher ("Servletcom.jsp"). Forward (request, response); } }}
PackageFirstservlet;Importjava.io.IOException;ImportJava.io.PrintWriter;Importjavax.servlet.ServletException;ImportJavax.servlet.annotation.WebServlet;ImportJavax.servlet.http.HttpServlet;Importjavax.servlet.http.HttpServletRequest;ImportJavax.servlet.http.HttpServletResponse;/*** Servlet Implementation class Result*/@WebServlet ("/result") Public classResultextendsHttpServlet {Private Static Final LongSerialversionuid = 1L; /** * @seeHttpservlet#httpservlet ()*/ PublicResult () {Super(); //TODO auto-generated Constructor stub } /** * @seeHttpservlet#doget (httpservletrequest request, httpservletresponse response)*/ protected voidDoget (HttpServletRequest request, httpservletresponse response)throwsservletexception, IOException {//TODO auto-generated Method StubDoPost (request, response); } /** * @seeHttpservlet#dopost (httpservletrequest request, httpservletresponse response)*/ protected voidDoPost (HttpServletRequest request, httpservletresponse response)throwsservletexception, IOException {//TODO auto-generated Method StubResponse.setcontenttype ("Text/html;charset=utf-8"); PrintWriter out=Response.getwriter (); Out.println ("); intSn= (int) Request.getattribute ("SN"); intEn= (int) Request.getattribute ("EN")); Out.println ("); Out.print ("Start number:" +sn+ "terminating number:" +EN); Out.println ("); for(inti=sn;i<=en;i++){ for(intj=sn;j<=i;j++) {out.print (i); Out.print ("*"); Out.print (j); Out.print ("="); Out.print (i*j); Out.print (" "); } out.print ("<br>"); } }}
Examples of effects:Alert () Pop-up window:
Jsp/servlet Web Learning Note dayfour--to implement a simple jsp/servlet interaction