基于JavaWeb的学生信息管理系统

package servlet; import util.DBUtil; import java.io.IOException; import java.io.PrintWriter; import java.sql.Connection; import java.sql.DriverManager; import java.sql.PreparedStatement; import java.sql.ResultSet; import java.sql.SQLException; import javax.servlet.ServletException; import javax.servlet.annotation.WebServlet; import javax.servlet.http.HttpServlet; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; @WebServlet("/register") public class RegisterServlet extends HttpServlet { private static final long serialVersionUID = 1L; protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { String username = request.getParameter("username"); String password = request.getParameter("password"); String confirmPassword = request.getParameter("confirm-password"); response.setCharacterEncoding("UTF-8"); response.setContentType("text/html"); PrintWriter out = response.getWriter(); if (password.equals(confirmPassword)) { Connection conn = null; PreparedStatement stmt = null; ResultSet rs = null; try { // 连接数据库 conn = DBUtil.getConnection(); // 查询是否已存在相同用户名 String query = "SELECT * FROM users WHERE username=?"; stmt = conn.prepareStatement(query); stmt.setString(1, username); rs = stmt.executeQuery(); if (rs.next()) { response.sendRedirect("register.jsp"); } else { // 在此处执行注册逻辑，例如将用户名和密码保存到数据库 String sql = "INSERT INTO users(username,password) VALUES(?,?)"; stmt = conn.prepareStatement(sql); stmt.setString(1, new String(username.getBytes("UTF-8"), "UTF-8")); stmt.setString(2, new String(password.getBytes("UTF-8"), "UTF-8")); stmt.executeUpdate(); // 注册成功后重定向到index页面 response.sendRedirect("index.jsp"); } } catch (Exception e) { e.printStackTrace(); } finally { // 关闭数据库连接和资源 DBUtil.close(conn, stmt, rs); } } } }