[Javaweb Basic] 004. Use JSP + SERVLET to make simple additions and deletions

Last time, we explained how to use Java to access MySQL database, to increase the deletion of data to modify the query . So this time we combine the database operations of specific pages to conduct a simple case of student information Operation .

First we create a Manageservletthat is dedicated to student management .

　　

Then we need a page that shows the data, which is userlist.jsp

<% @page import= "com.babybus.sdteam.vo.Student"%><%@ page language= "java" import= "java.util.*" pageencoding　　= "GB18030"%><% String Path = Request.getcontextpath (); String basepath = request.getscheme () + "://" +request.getservername () + ":" +request.getserverport () +path+ "/";%> <! DOCTYPE HTML PUBLIC "-//w3c//dtd HTML 4.01 transitional//en" >
 Next we need a page adduser.jsp  
 
<% @page import= "Com.babybus.sdteam.bo.ManageServlet"%><% @page import= "com.babybus.sdteam.vo.Student"% ><% @page import= "com.babybus.sdteam.bo.LoginServlet"%><%@ page language= "java" import= "java.util.*" pageencoding= "UTF-8"%><%string path = Request.getcontextpath (); String basepath = request.getscheme () + "://" +request.getservername () + ":" +request.getserverport () +path+ "/"; Response.setcontenttype ("Text/html;charset=utf-8"); Request.setcharacterencoding ("UTF-8");%><! DOCTYPE HTML PUBLIC "-//w3c//dtd HTML 4.01 transitional//en" >
 With page support, we need the background of servlet   data processing forwarding  
 
/*** Business Processing * @param req* @param rep* @throws ioexception * @throws servletexception */public void Process (httpservletrequest　　Req,httpservletresponse rep) throws Servletexception, ioexception{String method = Req.getparameter ("method");　　System.out.println ("Operation:" + method);　　Student Student = new Student (); if (! " Del ". Equals (method)) {//Encode conversion, avoid Chinese garbled string studentname = new String (Req.getparameter (" Studentname "). GetBytes (" I　　　　So-8859-1 ")," Utf-8 ");　　　　int age = Integer.parseint (Req.getparameter ("Age"));　　　　String classname = new String (Req.getparameter ("classname"). GetBytes ("Iso-8859-1"), "Utf-8");　　　　Student.setstudentname (Studentname);　　　　Student.setage (age);　　Student.setclassname (classname);　　} Studentdao DAO = new Studentdao ();　　　　Modify if ("Update". Equals (method)) {String id = req.getparameter ("userid");　　　　Student.setid (Integer.parseint (id));　　　　try {dao.updatestudent (student);　　　　} catch (SQLException e) {e.printstacktrace (); }}//Add ElsE if ("Add". Equals (method)) {try {dao.insertstudent (student);　　　　} catch (SQLException e) {e.printstacktrace ();　　　　　　}}//Remove else if ("Del". Equals (method)) {try {String id = req.getparameter ("userid");　　　　Dao.deletestudent (Integer.parseint (id));　　　　} catch (SQLException e) {e.printstacktrace (); }　　}
Manageservlet Manageservlet = new Manageservlet ();　　Get the full list list<student> resultlist = manageservlet.getstudentbycondition (null);　　Req.setattribute ("Students", resultlist);　　RequestDispatcher dispatcher = Req.getrequestdispatcher ("userlist.jsp"); Dispatcher.forward (req, rep); }
Above is all the added code to delete the changes. The following gives the effect of two pages
From the above example, we can get a good grasp of the introduction of the Java EE
Conclusion

 
  

  
   
 
    
Benefited, mastered the introduction of the Java EE
 
   
 
  
This site article is for  baby bus SD. Team  Original, reproduced must be clearly noted: (the author's official website: Baby bus )
Reprinted from "Baby bus Superdo Team" original link: http://www.cnblogs.com/superdo/p/4579275.html
[Javaweb Basic] 004. Use JSP + SERVLET to make simple additions and deletions