JAVA-EE使用JSTL标签和EL表达式改造OA项目消除JSP页面的JAVA代码------计算机网络经典

我就是我 2024-02-21 10:34 34阅读 0赞

>     <%@ page contentType="text/html;charset=UTF-8" language="java" %>
>     <%--引入标签库--%>
>     <%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>
>     <!DOCTYPE html>
>     <html>
>     <head>
>         <meta charset="utf-8">
>         <title>部门列表</title>
>     </head>
>     <body>
>     <script>
>         function del(dno){
>             var ok = window.confirm('亲,确认删除该数据吗?');
>             if(ok){
>                 document.location.href = "${pageContext.request.contextPath}/dept/delete?deptno=" + dno;
>             }
>         }
>     </script>
>         <h3>欢迎:<a href="">${username}</a></h3>
>         <h3><a href="${pageContext.request.contextPath}/user/exit">退出登录</a></h3>
>     <h1 align="center">部门列表</h1>
>     <hr>
>         <table align="center" border="1px" width="50%">
>             <tr>
>                 <th>序号</th>
>                 <th>部门编号</th>
>                 <th>部门名称</th>
>                 <th>操作</th>
>             </tr>
>             <c:forEach items="${depts}" var="dept" varStatus="deptStatue">
>                 <tr>
>                     <td>${deptStatue.count}</td>
>                     <td>${dept.deptno}</td>
>                     <td>${dept.dname}</td>
>                     <td>
>                         <a href="javascript:void(0)" onclick="del(${dept.deptno})">删除</a>
>                         <a href="<%=(request.getContextPath())%>/dept/detail?f=m&deptno=${dept.deptno}">修改</a>
>                         <a href="<%=(request.getContextPath())%>/dept/detail?f=d&deptno=${dept.deptno}">详情</a>
>                     </td>
>                 </tr>
>             </c:forEach>
>         </table>
>         <hr>
>         <a href="${pageContext.request.contextPath}/add.jsp">新增部门</a>
>     </body>
>     </html>
> 
>     <%@ page contentType="text/html;charset=UTF-8" language="java" %>
>     <%--引入标签库--%>
>     <%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>
>     <!DOCTYPE html>
>     <html>
>     <head>
>         <meta charset="utf-8">
>         <title>部门列表</title>
>     </head>
>     <body>
>     <script>
>         function del(dno){
>             var ok = window.confirm('亲,确认删除该数据吗?');
>             if(ok){
>                 document.location.href = "${pageContext.request.contextPath}/dept/delete?deptno=" + dno;
>             }
>         }
>     </script>
>         <h3>欢迎:<a href="">${username}</a></h3>
>         <h3><a href="${pageContext.request.contextPath}/user/exit">退出登录</a></h3>
>     <h1 align="center">部门列表</h1>
>     <hr>
>         <table align="center" border="1px" width="50%">
>             <tr>
>                 <th>序号</th>
>                 <th>部门编号</th>
>                 <th>部门名称</th>
>                 <th>操作</th>
>             </tr>
>             <c:forEach items="${depts}" var="dept" varStatus="deptStatue">
>                 <tr>
>                     <td>${deptStatue.count}</td>
>                     <td>${dept.deptno}</td>
>                     <td>${dept.dname}</td>
>                     <td>
>                         <a href="javascript:void(0)" οnclick="del(${dept.deptno})">删除</a>
>                         <a href="<%=(request.getContextPath())%>/dept/detail?f=m&deptno=${dept.deptno}">修改</a>
>                         <a href="<%=(request.getContextPath())%>/dept/detail?f=d&deptno=${dept.deptno}">详情</a>
>                     </td>
>                 </tr>
>             </c:forEach>
>         </table>
>         <hr>
>         <a href="${pageContext.request.contextPath}/add.jsp">新增部门</a>
>     </body>
>     </html>

>     JSTL标签库
>     java标准的标签库,通常和EL表达式一起用,目的是让JSP中的java代码消失
>     JSTL提供了很多标签,按需引入即可,重点是核心标签库
>     prefix后面的是你给你的标签起的抬头名字
>     jstl核心底层还是java程序
>     <%--引入标签库--%>
>     <%@taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>
>     核心标签库的uri指向了一个tld文件,这个tld文件本质是xml文件
>     它描述了标签和java类之间的关系
> 
>     JSTL标签库
>     java标准的标签库,通常和EL表达式一起用,目的是让JSP中的java代码消失
>     JSTL提供了很多标签,按需引入即可,重点是核心标签库
>     prefix后面的是你给你的标签起的抬头名字
>     jstl核心底层还是java程序
>     <%--引入标签库--%>
>     <%@taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>
>     核心标签库的uri指向了一个tld文件,这个tld文件本质是xml文件
>     它描述了标签和java类之间的关系

>     <%@ page contentType="text/html;charset=UTF-8" language="java" %>
>     <!DOCTYPE html>
>     <html>
>     <head>
>         <meta charset="utf-8">
>         <title>部门详情</title>
>     </head>
>     <body>
>         <h3>欢迎${username}</h3>
>         <h1>部门详情</h1>
>         <hr>
>         部门编号:${dept.deptno}<br>
>         部门名称:${dept.dname}<br>
>         部门位置:${dept.loc}<br>
>         <input type="button" value="后退" onclick="window.history.back()"/>
>     </body>
>     </html>
> 
>     <%@ page contentType="text/html;charset=UTF-8" language="java" %>
>     <!DOCTYPE html>
>     <html>
>     <head>
>         <meta charset="utf-8">
>         <title>部门详情</title>
>     </head>
>     <body>
>         <h3>欢迎${username}</h3>
>         <h1>部门详情</h1>
>         <hr>
>         部门编号:${dept.deptno}<br>
>         部门名称:${dept.dname}<br>
>         部门位置:${dept.loc}<br>
>         <input type="button" value="后退" οnclick="window.history.back()"/>
>     </body>
>     </html>

>     <%@ page contentType="text/html;charset=UTF-8" language="java" %>
>     <!DOCTYPE html>
>     <html>
>     	<head>
>     		<meta charset="utf-8">
>     		<title>新增部门</title>
>     	</head>
>     	<body>
>     		<h3>欢迎${username}</h3>
>     		<h1>新增部门</h1>
>     		<hr>
>     		<form method="post" action="${pageContext.request.contextPath}/dept/save">
>     			部门编号:<input type="text" name="deptno"/><br>
>     			部门名称:<input type="text" name="dname"/><br>
>     			部门位置:<input type="text" name="loc"/><br>
>     			<input type="submit" value="保存"/>
>     		</form>
>     	</body>
>     </html>
> 
>     <%@ page contentType="text/html;charset=UTF-8" language="java" %>
>     <!DOCTYPE html>
>     <html>
>         <head>
>            <meta charset="utf-8">
>            <title>新增部门</title>
>         </head>
>         <body>
>            <h3>欢迎${username}</h3>
>            <h1>新增部门</h1>
>            <hr>
>            <form method="post" action="${pageContext.request.contextPath}/dept/save">
>               部门编号:<input type="text" name="deptno"/><br>
>               部门名称:<input type="text" name="dname"/><br>
>               部门位置:<input type="text" name="loc"/><br>
>               <input type="submit" value="保存"/>
>            </form>
>         </body>
>     </html>

>     <%@ page contentType="text/html;charset=UTF-8" language="java" %>
>     <!DOCTYPE html>
>     <html>
>     <head>
>         <meta charset="utf-8">
>         <title>修改部门</title>
>     </head>
>     <body>
>     <h3>欢迎${username}</h3>
>     <h1>修改部门</h1>
>     <hr>
>     <form method="post" action="${pageContext.request.contextPath}/dept/edit">
>         部门编号:<input type="text" name="deptno" value="${dept.deptno}" readonly/><br>
>         部门名称:<input type="text" name="dname" value="${dept.dname}"/><br>
>         部门位置:<input type="text" name="loc" value="${dept.loc}"/><br>
>         <input type="submit" value="保存"/>
>     </form>
>     </body>
>     </html>
> 
>     <%@ page contentType="text/html;charset=UTF-8" language="java" %>
>     <!DOCTYPE html>
>     <html>
>     <head>
>         <meta charset="utf-8">
>         <title>修改部门</title>
>     </head>
>     <body>
>     <h3>欢迎${username}</h3>
>     <h1>修改部门</h1>
>     <hr>
>     <form method="post" action="${pageContext.request.contextPath}/dept/edit">
>         部门编号:<input type="text" name="deptno" value="${dept.deptno}" readonly/><br>
>         部门名称:<input type="text" name="dname" value="${dept.dname}"/><br>
>         部门位置:<input type="text" name="loc" value="${dept.loc}"/><br>
>         <input type="submit" value="保存"/>
>     </form>
>     </body>
>     </html>

>     <%@ page contentType="text/html;charset=UTF-8" isELIgnored="false" language="java" %>
>     <!DOCTYPE html>
>     <html>
>     <head>
>         <meta charset="utf-8">
>         <title>欢迎页</title>
>     </head>
>     <body>
>         <h1>用户登录</h1>
>         <hr>
>         <form action="${pageContext.request.contextPath}/user/login" method="post">
>             username:<input type="text" name="username"><br>
>             password:<input type="password" name="password"><br>
>             10天免登录:<input type="checkbox" name="flag" value="1"><br>
>             <input type="submit" value="login">
>         </form>
>     </body>
>     </html>
> 
>     <%@ page contentType="text/html;charset=UTF-8" isELIgnored="false" language="java" %>
>     <!DOCTYPE html>
>     <html>
>     <head>
>         <meta charset="utf-8">
>         <title>欢迎页</title>
>     </head>
>     <body>
>         <h1>用户登录</h1>
>         <hr>
>         <form action="${pageContext.request.contextPath}/user/login" method="post">
>             username:<input type="text" name="username"><br>
>             password:<input type="password" name="password"><br>
>             10天免登录:<input type="checkbox" name="flag" value="1"><br>
>             <input type="submit" value="login">
>         </form>
>     </body>
>     </html>

>     package com.bjpowernode.oa.web.action;
>     
>     import com.bjpowernode.oa.utils.DBUtil;
>     import com.bjpowernode.oa.web.Pojo.Dept;
>     import jakarta.servlet.ServletException;
>     import jakarta.servlet.annotation.WebServlet;
>     import jakarta.servlet.http.HttpServlet;
>     import jakarta.servlet.http.HttpServletRequest;
>     import jakarta.servlet.http.HttpServletResponse;
>     import jakarta.servlet.http.HttpSession;
>     
>     import java.io.IOException;
>     import java.sql.Connection;
>     import java.sql.PreparedStatement;
>     import java.sql.ResultSet;
>     import java.sql.SQLException;
>     import java.util.ArrayList;
>     import java.util.List;
>     
>     @WebServlet(urlPatterns = {"/dept/list","/dept/detail","/dept/delete","/dept/save","/dept/edit"})
>     public class DeptServlet extends HttpServlet
>     {
>         @Override
>         protected void service(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException
>         {
>             HttpSession session = request.getSession(false);
>             String servletPath = request.getServletPath();
>             if(session != null && session.getAttribute("username") != null)
>             {
>                 if("/dept/list".equals(servletPath))
>                 {
>                     doList(request,response);
>                 }
>                 else if("/dept/detail".equals(servletPath))
>                 {
>                     doDetail(request,response);
>                 }
>                 else if("/dept/delete".equals(servletPath))
>                 {
>                     doDel(request,response);
>                 }
>                 else if("/dept/save".equals(servletPath))
>                 {
>                     doSave(request,response);
>                 }
>                 else if("/dept/edit".equals(servletPath))
>                 {
>                     doModify(request,response);
>                 }
>             }
>             else
>             {
>                 response.sendRedirect(request.getContextPath() + "/index.jsp");
>             }
>         }
>     
>         private void doModify(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException
>         {
>             request.setCharacterEncoding("UTF-8");
>             Integer deptno = Integer.parseInt(request.getParameter("deptno"));
>             String dname = request.getParameter("dname");
>             String loc = request.getParameter("loc");
>             Connection connection = null;
>             PreparedStatement statement = null;
>             ResultSet resultSet = null;
>             int count = 0;
>             try
>             {
>                 connection = DBUtil.getConnection();
>                 connection.setAutoCommit(false);
>                 String sql = "update dept set dname = ?,loc = ? where deptno = ?";
>                 statement = connection.prepareStatement(sql);
>                 statement.setString(1,dname);
>                 statement.setString(2,loc);
>                 statement.setInt(3,deptno);
>                 count = statement.executeUpdate();
>                 connection.commit();
>             }
>             catch (SQLException e)
>             {
>                 if (connection != null)
>                 {
>                     try
>                     {
>                         connection.rollback();
>                     }
>                     catch (SQLException ex)
>                     {
>                         throw new RuntimeException(ex);
>                     }
>                 }
>                 throw new RuntimeException(e);
>             }
>             finally
>             {
>                 DBUtil.close(connection,statement,resultSet);
>             }
>             if(count == 1)
>             {
>                 response.sendRedirect(request.getContextPath() +  "/dept/list");
>             }
>             else
>             {
>                 response.sendRedirect(request.getContextPath() + "/Error.jsp");
>             }
>         }
>     
>         private void doSave(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException
>         {
>             request.setCharacterEncoding("UTF-8");
>             Integer deptno = Integer.parseInt(request.getParameter("deptno"));
>             String dname = request.getParameter("dname");
>             String loc = request.getParameter("loc");
>             Connection connection = null;
>             PreparedStatement statement = null;
>             ResultSet resultSet = null;
>             int count = 0;
>             try
>             {
>                 connection = DBUtil.getConnection();
>                 connection.setAutoCommit(false);
>                 String sql = "insert into dept(deptno,dname,loc) values(?,?,?)";
>                 statement = connection.prepareStatement(sql);
>                 statement.setInt(1,deptno);
>                 statement.setString(2,dname);
>                 statement.setString(3,loc);
>                 count = statement.executeUpdate();
>                 connection.commit();
>     
>             }
>             catch (SQLException e)
>             {
>                 if (connection != null)
>                 {
>                     try
>                     {
>                         connection.rollback();
>                     }
>                     catch (SQLException ex)
>                     {
>                         throw new RuntimeException(ex);
>                     }
>                 }
>                 throw new RuntimeException(e);
>             }
>             finally
>             {
>                 DBUtil.close(connection,statement,resultSet);
>             }
>             if(count == 1)
>             {
>                 response.sendRedirect(request.getContextPath() +  "/dept/list");
>             }
>             else
>             {
>                 response.sendRedirect(request.getContextPath() + "/Error.jsp");
>             }
>         }
>     
>         private void doDel(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException
>         {
>             Connection connection = null;
>             PreparedStatement statement = null;
>             ResultSet resultSet = null;
>             String deptno = request.getParameter("deptno");
>             int count = 0;
>             try
>             {
>                 connection = DBUtil.getConnection();
>                 connection.setAutoCommit(false);
>                 String sql = "delete from dept where deptno = ?";
>                 statement = connection.prepareStatement(sql);
>                 statement.setString(1,deptno);
>                 count = statement.executeUpdate();
>                 connection.commit();
>             }
>             catch (SQLException e)
>             {
>                 if (connection != null)
>                 {
>                     try
>                     {
>                         connection.rollback();
>                     }
>                     catch (SQLException ex)
>                     {
>                         throw new RuntimeException(ex);
>                     }
>                 }
>                 throw new RuntimeException(e);
>             }
>             finally
>             {
>                 DBUtil.close(connection,statement,resultSet);
>             }
>             if(count == 1)
>             {
>                 response.sendRedirect(request.getContextPath() + "/dept/list");
>             }
>             else
>             {
>                 response.sendRedirect(request.getContextPath() + "/Error.jsp");
>             }
>         }
>     
>         private void doDetail(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException
>         {
>             Connection connection = null;
>             PreparedStatement statement = null;
>             ResultSet resultSet = null;
>             String deptno = request.getParameter("deptno");
>             try
>             {
>                 connection = DBUtil.getConnection();
>                 String sql = "select * from dept where deptno = ?";
>                 statement = connection.prepareStatement(sql);
>                 statement.setString(1,deptno);
>                 resultSet = statement.executeQuery();
>                 if(resultSet.next())
>                 {
>                     String dname = resultSet.getString("dname");
>                     String loc = resultSet.getString("loc");
>                     Dept dept = new Dept(deptno,dname,loc);
>                     request.setAttribute("dept",dept);
>                 }
>             }
>             catch (SQLException e)
>             {
>                 throw new RuntimeException(e);
>             }
>             finally
>             {
>                 DBUtil.close(connection,statement,resultSet);
>             }
>             String flag = request.getParameter("f");
>             if("d".equals(flag))
>             {
>                 request.getRequestDispatcher("/detail.jsp").forward(request,response);
>             }
>             if("m".equals(flag))
>             {
>                 request.getRequestDispatcher("/edit.jsp").forward(request,response);
>             }
>         }
>     
>         private void doList(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException
>         {
>             //连接数据库,查询所有部门信息
>             Connection connection = null;
>             PreparedStatement statement = null;
>             ResultSet resultSet = null;
>             List<Dept> list = new ArrayList<Dept>();
>             try
>             {
>                 connection = DBUtil.getConnection();
>                 String sql = "select * from dept";
>                 statement = connection.prepareStatement(sql);
>                 resultSet = statement.executeQuery();
>                 while(resultSet.next())
>                 {
>                     String deptno = resultSet.getString("deptno");
>                     String dname = resultSet.getString("dname");
>                     String loc = resultSet.getString("loc");
>                     Dept dept = new Dept(deptno,dname,loc);
>                     list.add(dept);
>                 }
>                 request.setAttribute("depts",list);
>                 request.getRequestDispatcher("/list.jsp").forward(request,response);
>             }
>             catch (SQLException e)
>             {
>                 throw new RuntimeException(e);
>             }
>             finally
>             {
>                 DBUtil.close(connection,statement,resultSet);
>             }
>         }
>     }
> 
>     package com.bjpowernode.oa.web.action;
>     
>     import com.bjpowernode.oa.utils.DBUtil;
>     import com.bjpowernode.oa.web.Pojo.Dept;
>     import jakarta.servlet.ServletException;
>     import jakarta.servlet.annotation.WebServlet;
>     import jakarta.servlet.http.HttpServlet;
>     import jakarta.servlet.http.HttpServletRequest;
>     import jakarta.servlet.http.HttpServletResponse;
>     import jakarta.servlet.http.HttpSession;
>     
>     import java.io.IOException;
>     import java.sql.Connection;
>     import java.sql.PreparedStatement;
>     import java.sql.ResultSet;
>     import java.sql.SQLException;
>     import java.util.ArrayList;
>     import java.util.List;
>     
>     @WebServlet(urlPatterns = {"/dept/list","/dept/detail","/dept/delete","/dept/save","/dept/edit"})
>     public class DeptServlet extends HttpServlet
>     {
>         @Override
>         protected void service(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException
>         {
>             HttpSession session = request.getSession(false);
>             String servletPath = request.getServletPath();
>             if(session != null && session.getAttribute("username") != null)
>             {
>                 if("/dept/list".equals(servletPath))
>                 {
>                     doList(request,response);
>                 }
>                 else if("/dept/detail".equals(servletPath))
>                 {
>                     doDetail(request,response);
>                 }
>                 else if("/dept/delete".equals(servletPath))
>                 {
>                     doDel(request,response);
>                 }
>                 else if("/dept/save".equals(servletPath))
>                 {
>                     doSave(request,response);
>                 }
>                 else if("/dept/edit".equals(servletPath))
>                 {
>                     doModify(request,response);
>                 }
>             }
>             else
>             {
>                 response.sendRedirect(request.getContextPath() + "/index.jsp");
>             }
>         }
>     
>         private void doModify(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException
>         {
>             request.setCharacterEncoding("UTF-8");
>             Integer deptno = Integer.parseInt(request.getParameter("deptno"));
>             String dname = request.getParameter("dname");
>             String loc = request.getParameter("loc");
>             Connection connection = null;
>             PreparedStatement statement = null;
>             ResultSet resultSet = null;
>             int count = 0;
>             try
>             {
>                 connection = DBUtil.getConnection();
>                 connection.setAutoCommit(false);
>                 String sql = "update dept set dname = ?,loc = ? where deptno = ?";
>                 statement = connection.prepareStatement(sql);
>                 statement.setString(1,dname);
>                 statement.setString(2,loc);
>                 statement.setInt(3,deptno);
>                 count = statement.executeUpdate();
>                 connection.commit();
>             }
>             catch (SQLException e)
>             {
>                 if (connection != null)
>                 {
>                     try
>                     {
>                         connection.rollback();
>                     }
>                     catch (SQLException ex)
>                     {
>                         throw new RuntimeException(ex);
>                     }
>                 }
>                 throw new RuntimeException(e);
>             }
>             finally
>             {
>                 DBUtil.close(connection,statement,resultSet);
>             }
>             if(count == 1)
>             {
>                 response.sendRedirect(request.getContextPath() +  "/dept/list");
>             }
>             else
>             {
>                 response.sendRedirect(request.getContextPath() + "/Error.jsp");
>             }
>         }
>     
>         private void doSave(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException
>         {
>             request.setCharacterEncoding("UTF-8");
>             Integer deptno = Integer.parseInt(request.getParameter("deptno"));
>             String dname = request.getParameter("dname");
>             String loc = request.getParameter("loc");
>             Connection connection = null;
>             PreparedStatement statement = null;
>             ResultSet resultSet = null;
>             int count = 0;
>             try
>             {
>                 connection = DBUtil.getConnection();
>                 connection.setAutoCommit(false);
>                 String sql = "insert into dept(deptno,dname,loc) values(?,?,?)";
>                 statement = connection.prepareStatement(sql);
>                 statement.setInt(1,deptno);
>                 statement.setString(2,dname);
>                 statement.setString(3,loc);
>                 count = statement.executeUpdate();
>                 connection.commit();
>     
>             }
>             catch (SQLException e)
>             {
>                 if (connection != null)
>                 {
>                     try
>                     {
>                         connection.rollback();
>                     }
>                     catch (SQLException ex)
>                     {
>                         throw new RuntimeException(ex);
>                     }
>                 }
>                 throw new RuntimeException(e);
>             }
>             finally
>             {
>                 DBUtil.close(connection,statement,resultSet);
>             }
>             if(count == 1)
>             {
>                 response.sendRedirect(request.getContextPath() +  "/dept/list");
>             }
>             else
>             {
>                 response.sendRedirect(request.getContextPath() + "/Error.jsp");
>             }
>         }
>     
>         private void doDel(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException
>         {
>             Connection connection = null;
>             PreparedStatement statement = null;
>             ResultSet resultSet = null;
>             String deptno = request.getParameter("deptno");
>             int count = 0;
>             try
>             {
>                 connection = DBUtil.getConnection();
>                 connection.setAutoCommit(false);
>                 String sql = "delete from dept where deptno = ?";
>                 statement = connection.prepareStatement(sql);
>                 statement.setString(1,deptno);
>                 count = statement.executeUpdate();
>                 connection.commit();
>             }
>             catch (SQLException e)
>             {
>                 if (connection != null)
>                 {
>                     try
>                     {
>                         connection.rollback();
>                     }
>                     catch (SQLException ex)
>                     {
>                         throw new RuntimeException(ex);
>                     }
>                 }
>                 throw new RuntimeException(e);
>             }
>             finally
>             {
>                 DBUtil.close(connection,statement,resultSet);
>             }
>             if(count == 1)
>             {
>                 response.sendRedirect(request.getContextPath() + "/dept/list");
>             }
>             else
>             {
>                 response.sendRedirect(request.getContextPath() + "/Error.jsp");
>             }
>         }
>     
>         private void doDetail(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException
>         {
>             Connection connection = null;
>             PreparedStatement statement = null;
>             ResultSet resultSet = null;
>             String deptno = request.getParameter("deptno");
>             try
>             {
>                 connection = DBUtil.getConnection();
>                 String sql = "select * from dept where deptno = ?";
>                 statement = connection.prepareStatement(sql);
>                 statement.setString(1,deptno);
>                 resultSet = statement.executeQuery();
>                 if(resultSet.next())
>                 {
>                     String dname = resultSet.getString("dname");
>                     String loc = resultSet.getString("loc");
>                     Dept dept = new Dept(deptno,dname,loc);
>                     request.setAttribute("dept",dept);
>                 }
>             }
>             catch (SQLException e)
>             {
>                 throw new RuntimeException(e);
>             }
>             finally
>             {
>                 DBUtil.close(connection,statement,resultSet);
>             }
>             String flag = request.getParameter("f");
>             if("d".equals(flag))
>             {
>                 request.getRequestDispatcher("/detail.jsp").forward(request,response);
>             }
>             if("m".equals(flag))
>             {
>                 request.getRequestDispatcher("/edit.jsp").forward(request,response);
>             }
>         }
>     
>         private void doList(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException
>         {
>             //连接数据库,查询所有部门信息
>             Connection connection = null;
>             PreparedStatement statement = null;
>             ResultSet resultSet = null;
>             List<Dept> list = new ArrayList<Dept>();
>             try
>             {
>                 connection = DBUtil.getConnection();
>                 String sql = "select * from dept";
>                 statement = connection.prepareStatement(sql);
>                 resultSet = statement.executeQuery();
>                 while(resultSet.next())
>                 {
>                     String deptno = resultSet.getString("deptno");
>                     String dname = resultSet.getString("dname");
>                     String loc = resultSet.getString("loc");
>                     Dept dept = new Dept(deptno,dname,loc);
>                     list.add(dept);
>                 }
>                 request.setAttribute("depts",list);
>                 request.getRequestDispatcher("/list.jsp").forward(request,response);
>             }
>             catch (SQLException e)
>             {
>                 throw new RuntimeException(e);
>             }
>             finally
>             {
>                 DBUtil.close(connection,statement,resultSet);
>             }
>         }
>     }