servlet编译

Question

我这里有个登陆的servlet 但是他不能编译 总是报错请高手指出一下错误吧
package com.wxpn.tutorial.servlet;import java.io.IOException;
import java.util.Collection;import javax.servlet.ServletException;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;import com.wxpn.tutorial.control.news.MasterMgr;
public class LoginServlet extends javax.servlet.http.HttpServlet implements
javax.servlet.Servlet {

public LoginServlet() {
super();
}
protected void doPost(HttpServletRequest request,
HttpServletResponse response) throws ServletException,
                                      IOException {
response.setContentType("text/html;charset=UTF-8");

// 获取提交的用户名：
String strUserName = request.getParameter("username");
// 获取提交的密码：
String strPassword = request.getParameter("password");
MasterMgr masterMgr = new MasterMgr();
if (masterMgr.checkLogin(strUserName, strPassword)) {
// 登录成功时,把strUserName设成session变量UserName
request.getSession(true).setAttribute("username", strUserName);
request.getSession(true).setAttribute("password", strPassword);
masterMgr.addloginnum(strUserName); response.sendRedirect("admin/main.jsp");
} else {
response.sendRedirect("admin/loginerror.jsp");
} }
}

Answer 1

public LoginServlet() { 
super(); 
} 
----
你继承的不是接口吗？

Answer 2

public class LoginServlet extends javax.servlet.http.HttpServlet implements javax.servlet.Servlet ?
又extends又implements?

Answer 3

public class LoginServlet extends javax.servlet.http.HttpServlet implements 
javax.servlet.Servlet { public LoginServlet() { 
super(); 
} 这里有错,改下~!

Answer 4

servlet就继承httpServlet就可以了吧,没必要实现Servlet吧