JavaWeb项目.zip

package com.servlet; import java.io.IOException; 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("/Servlet2") public class Servlet2 extends HttpServlet { private static final long serialVersionUID = 1L; public Servlet2() { super(); } protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { request.setCharacterEncoding("utf-8"); response.setCharacterEncoding("utf-8"); response.setContentType("text/html"); String username=request.getParameter("username"); String password=request.getParameter("password");try { Class.forName("com.mysql.cj.jdbc.Driver"); } catch (ClassNotFoundException e) { response.getWriter().println("驱动注册失败"); e.printStackTrace(); } Connection conn = null; ResultSet res = null; PreparedStatement ps = null; try { conn = DriverManager.getConnection("jdbc:mysql://localhost:3306/javaweb","root","1234"); System.out.println("数据库连接成功"); String sql1 = "select * from t_user"; ps = conn.prepareStatement(sql1); res = ps.executeQuery(); if (res.next()) { String username2 = res.getString(1); if(username2.equals(username)){ response.getWriter().println("账号重复，请重新注册"); return; } } String sql2= "insert into t_user(username,password) values(?,?)"; ps=conn.prepareStatement(sql2); ps.setString(1, username); ps.setString(2, password); int rows = ps.executeUpdate(); if(rows > 0) { response.getWriter().println("registerSuccess"); } else { response.getWriter().println("registerFull"); } if(res != null) { try { res.close(); } catch (SQLException e) { e.printStackTrace(); } } if (ps != null) { try { ps.close(); } catch (SQLException e) { e.printStackTrace(); } } } catch (SQLException e) { e.printStackTrace(); response.getWriter().println("数据库连接失败!请检查协议、IP、端口号或者用户名和密码是否有错"); } finally { if (conn != null) { try { conn.close(); } catch (SQLException e) { e.printStackTrace(); } } } } protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { doGet(request, response); } }