[JavaWeb基础] 004.用JSP + SERVLET 进行简单的增加删除修改

  上一次的文章,我们讲解了如何用JAVA访问MySql数据库,对数据进行增加删除修改查询。那么这次我们把具体的页面的数据库操作结合在一起,进行一次简单的学生信息操作案例。

  首先我们创建一个专门用于学生管理的ManageServlet。

  [JavaWeb基础] 004.用JSP + SERVLET 进行简单的增加删除修改

  接着我们需要一个展现数据的页面,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>学生信息管理</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>学生姓名</th>
  <th>年龄</th>
<th>班级</th>
<th>操作</th>
  </tr>
  <%
// 获取学生列表数据
List<Student> lsUser=(List)request.getAttribute("students");
if(lsUser==null||lsUser.size()==0){
    pageContext.setAttribute("theUser","1");
}else{
  // 遍历列表生成表格数据
   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('确定要删除么?')" }>删除</a>
  </td>
</tr>
<%
   }
}
%>
</table>
             <a href="AddUser.jsp">增加<a/>
</body>
</html>

  接下来我们需要一个进行增加修改的页面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="学生信息管理">
  <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">${title}</td>
  </tr>
  <tr>
    <td align="right">学生名</td>
    <td>
  <input type="text" name="studentname" value="${theUser.studentname}">
</td>   
</tr>
  <tr>
    <td align="right">年龄:</td>
    <td> 
  <input type="text" name="age" value="${theUser.age}">
</td>   
</tr>     
<tr>
    <td align="right">班级:</td>
    <td> 
  <input type="text" name="classname" value="${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>

  有了页面支撑,我们需要后台的Servlet进行数据处理转发

/**
* 业务处理
* @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)) {
    // 进行编码转换,避免中文乱码
    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();
    }
  }
  // 删除
  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();
  // 获取全部列表
  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删除修改的代码。下面给出两个页面的截图效果

[JavaWeb基础] 004.用JSP + SERVLET 进行简单的增加删除修改

[JavaWeb基础] 004.用JSP + SERVLET 进行简单的增加删除修改

  通过上面的例子我们就可以很好的掌握了J2EE的入门

结语

  • 受益,掌握了J2EE的入门

[JavaWeb基础] 004.用JSP + SERVLET 进行简单的增加删除修改

本站文章为宝宝巴士 SD.Team原创,转载务必在明显处注明:(作者官方网站:宝宝巴士)

转载自【宝宝巴士SuperDo团队】 原文链接: http://www.cnblogs.com/superdo/p/4579275.html

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