Servlet代码
@WebServlet("/UpdateStudent")
public class UpdateStudent extends HttpServlet {
private static final long serialVersionUID = 1L;
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
String idStr = request.getParameter("id");
if(idStr != null && !idStr.equals("")){
int id = Integer.valueOf(idStr);
AdminDao dao = new AdminDao();
Student stu = dao.selectStudentById(id);
request.setAttribute("stu", stu);
}
request.getRequestDispatcher("/UpdateStudent.jsp").forward(request, response);
}
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
String sname = request.getParameter("sname");
String password = request.getParameter("password");
String sno = request.getParameter("sno");
String sex = request.getParameter("sex");
String major = request.getParameter("major");
String grade = request.getParameter("grade");
Student student = new Student();
student.setSname(new String(sname.getBytes("ISO-8859-1"),"UTF-8"));
student.setPassword(password);
student.setSno(sno);
student.setSex(new String(sex.getBytes("ISO-8859-1"),"UTF-8"));
student.setMajor(new String(major.getBytes("ISO-8859-1"),"UTF-8"));
student.setGrade(new String(grade.getBytes("ISO-8859-1"),"UTF-8"));
AdminDao dao = new AdminDao();
dao.UpdateStudent(student);
request.getRequestDispatcher("/Information").forward(request, response);
}
Dao代码
public void UpdateStudent(Student stu) {
try {
Class.forName("com.mysql.jdbc.Driver");
String url = "jdbc:mysql://127.0.0.1:3306/appoi";
Connection con = DriverManager.getConnection(url, "root", "123348");
String sql = "update student set sname=?,password =?,sno=?,sex=?,major=?,grade=? where id=?";
PreparedStatement cmd = con.prepareStatement(sql);
cmd.setInt(1, stu.getId());
cmd.setString(2, stu.getSname());
cmd.setString(3, stu.getPassword());
cmd.setString(4, stu.getSno());
cmd.setString(5, stu.getSex());
cmd.setString(6, stu.getMajor());
cmd.setString(7, stu.getGrade());
cmd.executeUpdate();
con.close();
} catch (ClassNotFoundException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
//根据学生ID进行查询
public Student selectStudentById(int id){
Student stu = null;
try {
Class.forName("com.mysql.jdbc.Driver");
String url = "jdbc:mysql://127.0.0.1:3306/appoi";
Connection con = DriverManager.getConnection(url, "root", "123348");
String sql = "select * from student where id = "+id;
PreparedStatement pst = con.prepareStatement(sql);
ResultSet rst = pst.executeQuery();
while (rst.next()) {
stu = new Student();
stu.setId(rst.getInt("id"));
stu.setSname(rst.getString("sname"));
stu.setPassword(rst.getString("password"));
stu.setSno(rst.getString("sno"));
stu.setSex(rst.getString("sex"));
stu.setMajor(rst.getString("major"));
stu.setGrade(rst.getString("grade"));
}
con.close();
}
catch (ClassNotFoundException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
return stu; //返回
}
jsp的form表单
<form action="UpdateStudent?id=<%=stu.getId() %>" method="post">
<table>
<tr><td>学生编号：<input type="text" name="id" value="${stu.id }" /></td></tr>
<tr><td>登录名：<input type="text" name="sname" value="${stu.sname }"/></td></tr>
<tr><td>密码：<input type="password" name="password" value="${stu.password }"/></td></tr>
<tr><td>学号：<input type="text" name="sno" value="${stu.sno }"/></td></tr>
<tr><td>性别：<input type="text" name="sex" value="${stu.sex }"/></td></tr>
<tr><td>专业：<input type="text" name="major" value="${stu.major }"/></td></tr>
<tr><td>班级：<input type="text" name="grade" value="${stu.grade }"/></td></tr>
<tr><td ><input type="submit" value="提交"/></td></tr>
<tr><td><button type="submit" value="返回"/><a href="${pageContext.request.contextPath}/Information">返回</a></button></td></tr>
</table>
</form>
