Java 在Eclipse中，通过Jquery向Servlet发送Ajax查询很困难

我在Eclipse中的.jsp文件中运行了以下jQuery语句，该文件位于WebContent/public目录中：

        $(document).ready(function(){
        $('#login').click(function(){
            $('#display').html('Logging in...');
            var username = $('#username').val();
            var password = $('#password').val();
            $.ajax({
                url : '/AuthenticationServlet',
                type : 'POST',
                dataType : 'text',
                data : {'username' : username, 'password' :     password},
                success : function(data) {
                    $('#display').html('');
                    if(data != "SUCCESS"){
                        //TODO create an element to display validity
                        $('#display').html('Invalid Username/Password combination');
                    }else if (data == "SUCCESS"){
                        $('#username').val('');
                        $('#password').val('');
                        $('#display').html('Success!');                 
                    }   
                    else{
                        $('#display').html('Something has gone horribly wrong.');
                    }

                }
            });
            return false;
        });
    });

我在src/authentication目录中有我的servlet AuthenticationServlet，它的编写如下：

    /**
    * Servlet implementation class AuthenticationServlet
 */
@WebServlet("/AuthenticationServlet/*")
public class AuthenticationServlet extends HttpServlet {
    private static final long serialVersionUID = 1L;

    /**
     * Default constructor. 
     */
    public AuthenticationServlet() {
        // TODO Auto-generated constructor stub
    }

    /**
     * @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)
     */
    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        // TODO Auto-generated method stub
    }

    /**
     * @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
     * This method gets the username and password from the jsp file, then proceeds to pass them to
     * the authentication helper for validation.
     */
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        //get the parameters from the request
        String username = request.getParameter("username");
        String password = request.getParameter("password");

        //verify the login/password combination is correct

        boolean authenticated = AuthenticationHelper.verifyUser(username, password);

        if(authenticated){
            response.getWriter().write("SUCCESS");
        }
        else{
            response.getWriter().write("FAILURE");
        }
    }
}

---

问题是，在输入有效的用户名和密码组合时，JSP中我的“display”元素只会更改为“Logging in”，根本不会更改，这表示jquery不再执行任何代码，而这些代码最终会将元素更改为其他内容（无论是空的还是其他任何字符串）。我做错了什么？我的URL不正确吗

因为您希望以

username=usernameValue&password=passwordValu

e的形式发送请求。因此，修改

url

和

data

如下：

  url : 'AuthenticationServlet', // Remove /, it will skip the context path.
  data : {username : username, password : password}, // Remove quotation.

---

尝试添加

error:function（）{alert（'error'）；}

，查看是否出现此警报，如果是，请在删除

数据类型后重试：“text”

。这会给出404，至少在本地主机上是这样