Java 编译问题 - Java / Web 开发

package com;

import javax.servlet.*;
import javax.servlet.http.*;
import java.io.*;
import java.util.*;

public class pageFilter extends HttpServlet implements Filter {
  public pageFilter() {
  try {
  init();
  } catch (Exception ex) {
  ex.printStackTrace();
  }
  }

  private FilterConfig filterConfig;
  //Handle the passed-in FilterConfig
  public void init(FilterConfig filterConfig) throws ServletException {
  this.filterConfig = filterConfig;
  //
  }

  //Process the request/response pair
  public void doFilter(ServletRequest request, ServletResponse response,
  FilterChain filterChain) {
  try {
  HttpServletRequest httpRequest = (HttpServletRequest) request;
  HttpServletResponse httpResponse = (HttpServletResponse) response;
  boolean isValid = true;
  String uriStr = httpRequest.getRequestURI();
  if (uriStr.indexOf("index.jsp") == -1
  && uriStr.indexOf("fail.jsp") == -1
  && uriStr.indexOf("chcek.jsp")==-1
  &&