201906G105/YDH/WebContent/Register_test.jsp

<%@ page language="java" contentType="text/html; charset=UTF-8"
	pageEncoding="UTF-8"%>
<%@ page import="java.sql.*,javax.sql.*,javax.naming.*,java.util.*"%>
<%
	Connection connect = null;
	boolean existence;
	request.setCharacterEncoding("UTF-8");
	String username =request.getParameter("username");
	String password =request.getParameter("password");
	String sex =request.getParameter("sex");
	String clas =request.getParameter("class");
	if (username == null && password == null) {
		out.print("注册的账号或密码不能为空，请重新输入");
%>
<a href="Register.jsp">请重新注册</a>
<%
	}
	
	try {
		InitialContext ctx = new InitialContext();
		DataSource ds = (DataSource) ctx.lookup("java:comp/env/jdbc/ydh");
		connect = ds.getConnection();
		Statement stmt = connect.createStatement();
		ResultSet rs = stmt.executeQuery(
				"select * from register where uname='" + username + "' and upassword='" + password + "'");
		if (rs.next()) {
			existence = true;
		} else {
			existence = false;
		}
		if (existence) {
			connect.close();
			out.print("该用户以存在，请重新创建！");
			out.clear();
			out = pageContext.pushBody();
		} else {
			stmt.execute("insert into register value('"+username+"','"+password+"','"+clas+"','"+sex+"')");
			connect.close();
			request.setAttribute("msg","注册成功");
			request.getRequestDispatcher("login.jsp").forward(request, response);
		}
	} catch (Exception e) {
		e.printStackTrace();
	}
%>