標籤：
上一次的文章，我們講解了如何用JAVA訪問MySql資料庫，對資料進行增加刪除修改查詢。那麼這次我們把具體的頁面的資料庫操作結合在一起，進行一次簡單的學生資訊操作案例。
首先我們建立一個專門用於學生管理的ManageServlet。
接著我們需要一個展現資料的頁面，也就是 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"><html> <head> <base href="<%=basePath%>"> <title>學生資訊管理</title><meta http-equiv="pragma" content="no-cache"><meta http-equiv="cache-control" content="no-cache"><meta http-equiv="expires" content="0"> <meta http-equiv="keywords" content="keyword1,keyword2,keyword3"><meta http-equiv="description" content="This is my page"><link rel="stylesheet" type="text/css" href="styles.css"> </head><body> <%=basePath %> <table border="1" width="100%" > <tr><th>uid</th><th>學生姓名</th><th>年齡</th><th>班級</th><th>操作</th></tr> <% // 擷取學生列表資料 List<Student> lsUser=(List)request.getAttribute("students"); if(lsUser==null||lsUser.size()==0){ pageContext.setAttribute("theUser","1"); }else{ // 遍曆列表產生表格式資料 for(int i=0;i<lsUser.size();i++){ pageContext.setAttribute("theUser",lsUser.get(i)); %> <tr> <td>${theUser.id} </td><td>${theUser.studentname} </td><td>${theUser.age} </td><td>${theUser.classname} </td> <td><a href="AddUser.jsp?id=${theUser.id}">修改<a/>| <a href="Mangage?method=del&userid=${theUser.id}" onclick="return confirm(‘確定要刪除嗎？‘)" }>刪除</a></td> </tr> <% } } %> </table> <a href="AddUser.jsp">增加<a/> </body></html>
接下來我們需要一個進行增加修改的頁面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"><html> <head> <base href="<%=basePath%>"> <title>My JSP ‘AddUser.jsp‘ starting page</title> <meta http-equiv="pragma" content="no-cache"><meta http-equiv="cache-control" content="no-cache"><meta http-equiv="expires" content="0"> <meta http-equiv="keywords" content="keyword1,keyword2,keyword3"><meta http-equiv="description" content="學生資訊管理"><link rel="stylesheet" type="text/css" href="styles.css"> </head> <body> <% String id= request.getParameter("id"); if(id!=null){ ManageServlet loginServlet =new ManageServlet(); Student student = loginServlet.getStudentById(id); pageContext.setAttribute("theUser",student); pageContext.setAttribute("method","update"); pageContext.setAttribute("title","修改"); }else{pageContext.setAttribute("method","add"); pageContext.setAttribute("title","添加"); }%><form action="Mangage?method=${method}" method="post" ><input type="hidden" name="userid" value="${theUser.id}"><table width="100%" height="200px" border="1"><tr><td colspan="2">${title}</td></tr><tr><td align="right">學生名</td><td> <input type="text" name="studentname" value="${theUser.studentname}"></td></tr><tr><td align="right">年齡:</td><td> <input type="text" name="age" value="${theUser.age}"></td></tr><td align="right">班級:</td><td> <input type="text" name="classname" value="${theUser.classname}"></td></tr><tr><td colspan=‘2‘ align="center"><input type="submit" value="儲存" name="btnSubmit"> <input type="reset" value="重設" name="btnCancel"></td></tr></table></form></body></html>
有了頁面支撐，我們需要背景Servlet進行資料處理轉寄
/*** 業務處理* @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("操作:" + method); Student student = new Student(); if(!"del".equals(method)) { // 進行編碼轉換，避免中文亂碼 String studentname = new String(req.getParameter("studentname").getBytes("ISO-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(); // 修改 if("update".equals(method)) { String id = req.getParameter("userid"); student.setId(Integer.parseInt(id)); try { dao.updateStudent(student); } catch (SQLException e) { e.printStackTrace(); } } // 增加 else if("add".equals(method)) { try { dao.insertStudent(student); } catch (SQLException e) { e.printStackTrace(); } } // 刪除 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(); // 擷取全部列表 List<Student> resultlist = manageservlet.getStudentByCondition(null); req.setAttribute("students", resultlist); RequestDispatcher dispatcher = req.getRequestDispatcher("UserList.jsp"); dispatcher.forward(req, rep); }
上面就是全部的增加刪除修改的代碼。下面給出兩個頁面的效果
通過上面的例子我們就可以很好的掌握了J2EE的入門
結語
本站文章為 寶寶巴士 SD.Team 原創，轉載務必在明顯處註明：（作者官方網站： 寶寶巴士 )
轉載自【寶寶巴士SuperDo團隊】 原文連結: http://www.cnblogs.com/superdo/p/4579275.html
[JavaWeb基礎] 004.用JSP + SERVLET 進行簡單的增加刪除修改
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