大家好，尝试创建一个简单的数据库登录 java servlet。它会直接去
登录失败。请重试。
这是我的数据库的集合，我有表user-id，uniid，name , 密码, 电子邮件
例如我的表中有以下数据
uniid - 18357593
name - Jared Hoight
password - password
email - jhall@students.monash.edu.au
这是完整的登录 servlet
import java.io.IOException;
import java.io.PrintWriter;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.RequestDispatcher;
/**
* Servlet implementation class LoginServlet
*/
@WebServlet("/LoginServlet")
public class LoginServlet extends HttpServlet {
private static final long serialVersionUID = 1L;
/**
* @see HttpServlet#HttpServlet()
*/
public LoginServlet() {
super();
// TODO Auto-generated constructor stub
}
private void sendLoginForm(HttpServletResponse response,
boolean withErrorMessage)
throws ServletException, IOException {
response.setContentType("text/html");
PrintWriter out = response.getWriter();
out.println("<HTML>");
out.println("<HEAD>");
out.println("<TITLE>Login</TITLE>");
out.println("</HEAD>");
out.println("<BODY>");
out.println("<CENTER>");
if (withErrorMessage)
out.println("Login failed. Please try again.<BR>");
out.println("<BR>");
out.println("<BR><H2>Login Page</H2>");
out.println("<BR>");
out.println("<BR>Please enter your user name and password.");
out.println("<BR>");
out.println("<BR><FORM METHOD=POST>");
out.println("<TABLE>");
out.println("<TR>");
out.println("<TD>User Name:</TD>");
out.println("<TD><INPUT TYPE=TEXT NAME=uniid></TD>");
out.println("</TR>");
out.println("<TR>");
out.println("<TD>Password:</TD>");
out.println("<TD><INPUT TYPE=PASSWORD NAME=password></TD>");
out.println("</TR>");
out.println("<TR>");
out.println("<TD ALIGN=RIGHT COLSPAN=2>");
out.println("<INPUT TYPE=SUBMIT VALUE=Login></TD>");
out.println("</TR>");
out.println("</TABLE>");
out.println("</FORM>");
out.println("</CENTER>");
out.println("</BODY>");
out.println("</HTML>");
}
/**
* @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)
*/
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
sendLoginForm(response, false);
}
/**
* @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
*/
public void doPost(HttpServletRequest request,
HttpServletResponse response)
throws ServletException, IOException {
String uniid = request.getParameter("uniid");
String password = request.getParameter("password");
if (login(uniid, password)) {
RequestDispatcher rd =
request.getRequestDispatcher("AnotherServlet");
rd.forward(request, response);
}
else {
sendLoginForm(response, true);
}
}
boolean login(String uniid, String password) {
try {
Class.forName("sun.jdbc.odbc.JdbcOdbcDriver");
Connection con =
DriverManager.getConnection("jdbc:mysql://localhost:3306/wae","root","");
System.out.println("got connection");
Statement s = con.createStatement();
String sql = "SELECT uniid FROM user" +
" WHERE uniid='" + uniid + "'" +
" AND password='" + password + "'";
ResultSet rs = s.executeQuery(sql);
if (rs.next()) {
rs.close();
s.close();
con.close();
return true;
}
rs.close();
s.close();
con.close();
}
catch (ClassNotFoundException e) {
System.out.println(e.toString());
}
catch (SQLException e) {
System.out.println(e.toString());
}
catch (Exception e) {
System.out.println(e.toString());
}
return false;
}
}
最佳答案
数据库驱动
Class.forName("sun.jdbc.odbc.JdbcOdbcDriver");
不适合与 MySQL 一起使用。应该是
Class.forName("com.mysql.jdbc.Driver");
当您的 login 方法中发生异常时，将打印异常字符串并返回 false。
关于java - 登录 Servlet 直接变为 False，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/12666518/