Servelt + Jsp 的一个小示例

访问 StudentServlet 返回的页面是  list.jsp 经过 list.jsp 页面超链接 add
访问 StudentAddServlet 返回的页面时 add.jsp 提交表单 访问StudentAddProcessServlet 返回 List.jsp

再次经过 list.jsp 页面超链接 update , delete
访问 StudentUpdateServlet StudentDeleteServlet 返回的页面时 Update.jsp(提交表单访问StudentUpdateProcessServlet返回List.jsp) delete.jsp

***（jsp 与 servlet 中的调用时参数的发送和接受问题）***

—**************************(下面的其它jsp页面类同)*************************************

（

根据请求头调用doget  dopost

表单的  form表单中    method = post  为 dopost 调用

                      method = get  为 doget 调用

在浏览器中直接键入地址，为 doget 调用方法

表单的重复提交时 request 造成的
传递数据一定要使 request

）

（list.jsp页面接受servlet传过来的List ------- List list = (List)request.getAttribute("list");）

Update.jsp页面接受servlet传过来的List

Student stu = (Student)request.getAttribute("stu");
List list = (List)request.getAttribute("classsList");

以下是代码的实现

（StudentServlet   ）

public void List(HttpServletRequest request, HttpServletResponse response)
          throws ServletException, IOException, SQLException {
        
  StudentDAO studao = new StudentDAO();
  List list = studao.studentList();
  request.setAttribute("list", list);
  request.getRequestDispatcher("student/list.jsp").forward(request,response);
   }
（StudentAddServlet ）

public void add(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException, SQLException {
  ClasssDAO studao = new ClasssDAO();
  List list = studao.classList();
  request.setAttribute("classslist", list);
  request.getRequestDispatcher("student/add.jsp").forward(request, response);

}

（StudentAddProcessServlet ）

public void addProcess(HttpServletRequest request, HttpServletResponse response)
   throws ServletException, IOException, SQLException {
         request.setCharacterEncoding("utf-8");
         response.setCharacterEncoding("utf-8");
        
         String name = request.getParameter("name");
         String sex = request.getParameter("sex");
         String phone = request.getParameter("phone");
         int classsId = Integer.parseInt(request.getParameter("classsId"));
        
         StudentDAO studao = new StudentDAO();
         int row = studao.add(name, sex, phone, classsId);
        
         request.getSession().setAttribute("row", row);
         response.sendRedirect("result.jsp");

}

（StudentUpdateServlet ）

public void update(HttpServletRequest request, HttpServletResponse response)
   throws ServletException, IOException, SQLException {
  request.setCharacterEncoding("utf-8");
  response.setCharacterEncoding("utf-8");
  //取得参数
  int id = Integer.parseInt(request.getParameter("id"));

  StudentDAO studao = new StudentDAO();
  Student stu = studao.getstudentById(id);
 
  List list = new ClasssDAO().classList();
 
  request.setAttribute("stu", stu);
  request.setAttribute("classsList", list);
  request.getRequestDispatcher("student/update.jsp").forward(request, response);
}

（StudentUpdateProcessServlet ）

public void updateProcess(HttpServletRequest request, HttpServletResponse response)
   throws ServletException, IOException, SQLException {
  request.setCharacterEncoding("utf-8");
  response.setCharacterEncoding("utf-8");

  int id = Integer.parseInt(request.getParameter("id"));
  String name = request.getParameter("name");
  String sex = request.getParameter("sex");
  String phone = request.getParameter("phone");
  int classsId = Integer.parseInt(request.getParameter("classsId"));
 
  StudentDAO studao = new StudentDAO();
  int row = studao.update(id,name,sex,phone,classsId);
 
  request.getSession().setAttribute("row",row);
  response.sendRedirect("result.jsp");
 
}

（StudentDeleteProcessServlet ）

public void delete(HttpServletRequest request, HttpServletResponse response)
   throws ServletException, IOException, SQLException {
 
  request.setCharacterEncoding("utf-8");
  response.setCharacterEncoding("utf-8");
  int id = Integer.parseInt(request.getParameter("id"));

  StudentDAO stu = new StudentDAO();
  int row = stu.delete(id);
 
  request.getSession().setAttribute("row", row);
  response.sendRedirect("result.jsp");
}

----------------------------------------------------------------------------------

(List.Jsp)

      <table class="gridtable" style="width: 100%;">
     
    <tr>
      <th colspan="6" align="center">     
      <input type=button value="add" onclick="window.location.href='${basePath }StudentServlet?method=add'">
      <a href="#">import</a>&nbsp;
      <a href="d">export</a>
      </th>
    </tr>
    <tr>
      <th>id</th>
      <th>name</th>
      <th>sex</th>
      <th>phone</th>
      <th>classsid</th>
      <th>action</th>
     </tr>
    
     <c:forEach items="${list}" var="stu">
     <tr>
         <td>${stu.id}</td>
         <td>${stu.name}</td>
         <td>${stu.sex}</td>
         <td>${stu.phone}</td>
         <td>${stu.classsid}</td>
     <td>       
       <input type=button value="update" onclick="window.location.href='${basePath }StudentServlet?method=update&id=${stu.id}'">     
       <input type=button value="delete" onclick="window.location.href='${basePath }StudentServlet?method=delete&id=${stu.id}'">     
      </td>  
     </tr>    
     </c:forEach>
    </table>

(Add.Jsp)

   
    <form  action="${basePath}StudentAddProcessServlet" method="post">
   <table id="datagrid" class="gridtable" style="width: 100%;">
  
    <tr>
     <th>
      name
     </th>
     <td>
      <input type="text" name="name" value="" />
     </td>
    </tr>
    <tr>
     <th>
      sex
     </th>
     <td>
      <input type="text" name="sex" value="" />
     </td>
    </tr>
    <tr>
     <th>
      phone
     </th>
     <td>
      <input type="text" name="phone" value="" />
     </td>
    </tr>
   <tr>
     <th>
      classsId
     </th>
     <td>
     <select name="classsId">
      <c:forEach items="${classslist}" var="cla">
          <option value="${cla.id }">${cla.name }</option>     
      </c:forEach>
      </select>
     </td>
    </tr>
    <tr>
     <td colspan="2">
      <input type="submit" name="sub" value="提交" />
     </td>
    </tr>
   </table>
  </form>