上一次的文章，我們講解了如何用JAVA訪問MySql數據庫，對數據進行增加刪除修改查詢。那么這次我們把具體的頁面的數據庫操作結合在一起，進行一次簡單的學生信息操作案例。
首先我們創建一個專門用於學生管理的ManageServlet。
接着我們需要一個展現數據的頁面，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>學生信息管理</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>
<%
// 獲取學生列表數據
List<Student> lsUser=(List)request.getAttribute("students");
if(lsUser==null||lsUser.size()==0){
pageContext.setAttribute("theUser","1");
}else{
// 遍歷列表生成表格數據
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('確定要刪除么？')" }>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="學生信息管理">
<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="${theUser.age}">
</td>
</tr>
<tr>
<td align="right">班級:</td>
<td>
<input type="text" name="classname" value="${theUser.classname}">
</td>
</tr>
<tr>
<td colspan='2' align="center">
<input type="submit" value="保存" name="btnSubmit">
<input type="reset" value="重置" name="btnCancel">
</td>
</tr>
</table>
</form>
</body>
</html>
有了頁面支撐，我們需要后台的Servlet進行數據處理轉發
/**
* 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();
// 獲取全部列表
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截圖效果
通過上面的例子我們就可以很好的掌握了J2EE的入門
結語
- 受益，掌握了J2EE的入門
本站文章為 寶寶巴士 SD.Team 原創，轉載務必在明顯處注明：（作者官方網站： 寶寶巴士 )
轉載自【寶寶巴士SuperDo團隊】 原文鏈接: http://www.cnblogs.com/superdo/p/4579275.html