我在J2EE中的应用程序有问题。这是登录表单。当我输入登录名和密码时，我得到了
服务器遇到阻止它的内部错误 满足这个要求。
我的档案：
package facebookConnection.servlets;
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 facebookConnection.classes.Validate;
import java.sql.*;
/**
* Servlet implementation class Login
*/
@WebServlet("/Login")
public class Login extends HttpServlet {
private static final long serialVersionUID = 1L;
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
// TODO Auto-generated method stub
response.getWriter().append("Served at: ").append(request.getContextPath());
}
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
response.setContentType("text/html;charset=UTF-8");
PrintWriter out = response.getWriter();
String login = request.getParameter("login");
String password = request.getParameter("password");
if(Validate.checkUser(login,password))
{
RequestDispatcher rs = request.getRequestDispatcher("Welcome");
rs.forward(request, response);
}
else
{
out.println("Username or password nieprawidłowy");
RequestDispatcher rs = request.getRequestDispatcher("index.html");
rs.include(request, response);
}
}
}
package facebookConnection.classes;
import java.sql.*;
public class Validate {
public static boolean checkUser(String login, String password) {
boolean st = false;
try {
//loading drivers for mysql
Class.forName("com.mysql.jdbc.Driver");
//creating connection with database
Connection con = DriverManager.getConnection("jdbc:mysql://localhost:3306/facebook_connections","root","pass");
PreparedStatement ps = con.prepareStatement("select * from users where login=? and password=?");
ps.setString(1, login);
ps.setString(2, password);
ResultSet rs = ps.executeQuery();
st = rs.next();
} catch(Exception e) {
e.printStackTrace();
}
return st;
}
}
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>Login form</title>
</head>
<body>
<form action="login" method="post">
Login: <input type="text" name="login" /><br/>
Password: <input type="text" name="password" /><br/>
<input type="submit" value="login" />
</form>
</body>
</html>
package facebookConnection.servlets;
import javax.servlet.http.HttpServlet;
import java.io.*;
import javax.servlet.*;
import javax.servlet.http.*;
import java.sql.*;
public class Welcome extends HttpServlet {
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
response.setContentType("text/html;charset=UTF-8");
PrintWriter out = response.getWriter();
out.println("Welcome user");
}
}
<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://java.sun.com/xml/ns/javaee" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd" id="WebApp_ID" version="3.0">
<display-name>facebookConnect</display-name>
<welcome-file-list>
<welcome-file>index.html</welcome-file>
<welcome-file>index.htm</welcome-file>
<welcome-file>index.jsp</welcome-file>
<welcome-file>default.html</welcome-file>
<welcome-file>default.htm</welcome-file>
<welcome-file>default.jsp</welcome-file>
</welcome-file-list>
<servlet>
<servlet-name>Login</servlet-name>
<servlet-class>facebookConnection.servlets.Login</servlet-class>
</servlet>
<servlet>
<servlet-name>Welcome</servlet-name>
<servlet-class>facebookConnection.servlets.Welcome</servlet-class>
</servlet>
<servlet-mapping>
<servlet-name>Login</servlet-name>
<url-pattern>/login</url-pattern>
</servlet-mapping>
<servlet-mapping>
<servlet-name>Welcome</servlet-name>
<url-pattern>/welcome</url-pattern>
</servlet-mapping>
</web-app>
堆栈跟踪
javax.servlet.ServletException: Error instantiating servlet class facebookConnection.servlets.Login
org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:502)
org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:100)
org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:953)
org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:408)
org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1041)
org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:603)
org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:310)
java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
java.lang.Thread.run(Unknown Source)
root cause
java.lang.ClassNotFoundException: facebookConnection.servlets.Login
org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1702)
org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1547)
org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:502)
org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:100)
org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:953)
org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:408)
org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1041)
org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:603)
org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:310)
java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
java.lang.Thread.run(Unknown Source)
有人可以帮我吗？