JAVAEE_Servlet_20_登录注册功能

实现登录注册功能

• 注册功能

  
        import javax.servlet.ServletException;
        import javax.servlet.http.HttpServlet;
        import javax.servlet.http.HttpServletRequest;
        import javax.servlet.http.HttpServletResponse;
        import java.io.IOException;
        import java.io.PrintWriter;
        import java.sql.Connection;
        import java.sql.DriverManager;
        import java.sql.PreparedStatement;
        import java.sql.SQLException;
  
        public class RegisterServlet extends HttpServlet {
            @Override
            protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
                //解决中文乱码问题
                request.setCharacterEncoding("UTF-8");
  
                //获取表单数据
                String userName=request.getParameter("username");
                String userEmail=request.getParameter("email");
                String userPwd=request.getParameter("password");
  
                //创建数据库连接对象
                Connection connection=null;
                PreparedStatement preparedStatement=null;
  
                try {
                    // 连接数据库
                    Class.forName("com.mysql.cj.jdbc.Driver");
  
                    // 获取连接
                    connection= DriverManager.getConnection("jdbc:mysql://127.0.0.1:3306/mydb?useUnicode=true&characterEncoding=utf8&serverTimezone=Asia/Shanghai",
                            "root","123456");
  
                    // 获取预编译数据库操作对象
                    String sql="insert into t_userInfo(username,email,userpwd)values(?,?,?)";
                    preparedStatement=connection.prepareStatement(sql);
  
                    //给预编译数据库操作对象插入值
                    preparedStatement.setString(1,userName);
                    preparedStatement.setString(2,userEmail);
                    preparedStatement.setString(3,userPwd);
  
                    //执行SQL语句
                    int count=preparedStatement.executeUpdate();
  
                    // 显示执行结果
                    if(count!=0){
                        //跳转
                        response.sendRedirect("/myWeb/RegisterSuccess.html");
                    }
  
                } catch (ClassNotFoundException | SQLException e) {
                    e.printStackTrace();
                }finally {
                    //释放资源
                    if(preparedStatement!=null){
                        try {
                            preparedStatement.close();
                        } catch (SQLException e) {
                            e.printStackTrace();
                        }
                    }
  
                    if(connection!=null){
                        try {
                            connection.close();
                        } catch (SQLException e) {
                            e.printStackTrace();
                        }
                    }
                }
            }
        }
  
  

• 登录功能

  
  
     import javax.servlet.ServletException;
     import javax.servlet.http.HttpServlet;
     import javax.servlet.http.HttpServletRequest;
     import javax.servlet.http.HttpServletResponse;
     import java.io.IOException;
     import java.io.PrintWriter;
     import java.sql.*;
  
     public class LoginServlet extends HttpServlet {
         @Override
         protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
             //解决中文乱码问题
             request.setCharacterEncoding("UTF-8");
  
             //获取用户提交的表单数据
               String userEmail=request.getParameter("email");
               String userPwd=request.getParameter("password");
             //创建数据库连接对象
             Connection connection=null;
             PreparedStatement preparedStatement=null;
             ResultSet resultSet=null;
  
             try {
  
                 // 连接数据库
                 Class.forName("com.mysql.cj.jdbc.Driver");
  
                 // 获取连接
                 connection= DriverManager.getConnection("jdbc:mysql://127.0.0.1:3306/mydb?useUnicode=true&characterEncoding=utf8&serverTimezone=Asia/Shanghai",
                         "root","123456");
  
                 // 获取预编译数据库操作对象
                 String sql="select email,userpwd from t_userInfo where email=? and userpwd=?";
                 preparedStatement=connection.prepareStatement(sql);
  
                 //给预编译语句传参
                 preparedStatement.setString(1,userEmail);
                 preparedStatement.setString(2,userPwd);
  
                 //执行SQL语句
                 resultSet=preparedStatement.executeQuery();
  
                 //处理查询结果集
                 response.setContentType("text/html;charset=UTF-8");
                 PrintWriter out=response.getWriter();
                 //HTML代码
                 out.print("          <!DOCTYPE html>");
                 out.print("<meta http-equiv=\"content-type\" content=\"text/html\" charset=\"utf-8\"/> ");
                 out.print("  <head>");
                 out.print("      <meta charset='UTF-8'>");
                 out.print("      <title>用户信息</title>");
                 out.print("  </head>");
                 out.print("     <body>");
                 out.print("          <h3 align='center'>用户信息表</h3>");
                 out.print("          <hr width='60%'>");
                 out.print("          <table border='1' align='center' width='50%'>");
                 out.print("              <tr align='center'>");
                 out.print("                  <th>序号</th>");
                 out.print("                  <th>用户邮箱</th>");
                 out.print("                  <th>用户密码</th>");
                 out.print("              </tr>");
                 int i=1;
                 while(resultSet.next()){
                     String email=resultSet.getString("email");
                     String pwd=resultSet.getString("userpwd");
                     out.print("              <tr align='center'>");
                     out.print("                  <th>"+(i++)+"</th>");
                     out.print("                  <th>"+email+"</th>");
                     out.print("                  <th>"+pwd+"</th>");
                     out.print("              </tr>");
                 }
  
                 out.print("          </table>");
                 out.print("    </body>");
                 out.print("  </html>");
  
             } catch (ClassNotFoundException | SQLException e) {
                 e.printStackTrace();
             }finally {
  
                 //释放资源
                 if(resultSet!=null){
                     try {
                         resultSet.close();
                     } catch (SQLException e) {
                         e.printStackTrace();
                     }
                 }
                 if(preparedStatement!=null){
                     try {
                         preparedStatement.close();
                     } catch (SQLException e) {
                         e.printStackTrace();
                     }
                 }
  
                 if(connection!=null){
                     try {
                         connection.close();
                     } catch (SQLException e) {
                         e.printStackTrace();
                     }
                 }
             }
  
         }
     }