在这里，我创建了一个简单的 HTML 页面并转发给 servlet。但是 servlet 没有显示任何内容。问题是，它没有显示任何内容。输出是..
The output show while calling the servlet html是否有问题
My html code (login.html)
<!Doctype html>
<head>
<title>Login</title>
<link rel="stylesheet" type="text/css" href="header.css"/>
<style>
.content{
text-align:center;
position:absolute;
top:250px;
left:450px;
font-size:20px;
color:white;
}
#inputbox
{
height:30px;
width:300px;
}
#submit
{
color:white;
height:40px;
width:100px;
position:absolute;
top:150px;
background: #E8F0F0;
color:brown;
border:none;
}
body
{
background:url(Images/loginbackground.jpg);
}
</style>
</head>
<body>
<ol>
<li><a href="mainpage.html">Home</a></li>
<li><a href="courses.html">Courses</a></li>
<li><a href="">Contact Us</a></li>
<li id="signup"><a href="signup.html">Sign Up</a></li>
</ol>
<div class="content">
<form method="post" action="LoginCheck">
Username:<input type="text" name="username" placeholder="Enter your userID" id="inputbox" required/><br><br>
Password:<input type="password" name="password" placeholder="Enter Your password" id="inputbox" required/> <br><br>
<input type="submit" name="login" value="login" id="submit"/>
</form>
</div>
</body>
</html>
Whether the servlet was correct
Servlet code is (LoginCheck.java)
import java.io.IOException;
import java.io.PrintWriter;
//import javax.servlet.RequestDispatcher;
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 java.sql.*;
/**
* Servlet implementation class MySQLConnect
*/
@WebServlet("/LoginCheck")
public class LoginCheck extends HttpServlet {
private static final long serialVersionUID = 1L;
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
response.setContentType("text/html");
PrintWriter out = response.getWriter();
String username = request.getParameter("username");
String password = request.getParameter("password");
/*if((username.equalsIgnoreCase("jothibasu"))&&(password.equalsIgnoreCase("admin"))){
out.println("<div style='position: absolute; top:100px; left:400px;'>");
out.println("<font size='15' color='blue'>Welcome "+username+" !</font>");
out.println("</div>");
RequestDispatcher rd=request.getRequestDispatcher("/courses.html");
rd.include(request, response);
}
else{
out.println("<div style='position: absolute; top:180px; left:400px;'>");
out.println("<font size='15' color='darkgray'>Sorry UserName or Password Error!</font>");
out.println("</div>");
RequestDispatcher rd=request.getRequestDispatcher("/login.html");
rd.include(request, response);
}*/
try {
Class.forName("com.mysql.jdbc.Driver");
Connection conn = DriverManager.getConnection("jdbc:mysql://localhost:3306/startupdb", "root", "developer");
PreparedStatement pst = conn.prepareStatement("Select username,userpassword from logindetials where username=? and userpassword=?");
pst.setString(1, username);
pst.setString(2, password);
ResultSet rs = pst.executeQuery();
if (rs.next()) {
out.println("Correct login credentials");
}
else {
out.println("Incorrect login credentials");
}
}
catch (ClassNotFoundException | SQLException e) {
e.printStackTrace();
}
}
}
And my database & table goes here
最佳答案
改变内容类型如下，
response.setContentType("text/plain");
关于html - Servlet 在连接 mysql 时没有任何响应，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/40828075/