我为我的拍卖网络应用程序制作了两个过滤器。我实现了两个过滤器，第一个执行简单的日志记录操作，第二个检查用户是否有权访问特定资源。
问题是这些过滤器只有在我第一次连接到网站时才能正常工作。事实上，它会在工具栏中显示用户的名称，并且只有在您正确登录时才会发生这种情况。之后，我注销并重复该过程，但第二个过滤器根本不起作用。
我放置了 println 语句来检查过滤器是否实际执行，但事实并非如此。第一个过滤器不断工作。当我更改 xml 映射时，会出现奇怪的部分。事实上，当我为两个过滤器取出映射时，第一个过滤器继续工作！我昨天一整天都在发疯，试图理解这一点。
更奇怪的是，如果我重写过滤器的 xml 映射，它们在第一次登录过程中都起作用，但是，一旦我注销并重复操作，登录过滤器就不再起作用了。为了制作我的 Web 应用程序，我只是 JAVA7、netbeans 7.2 和 Tomcat 7。我担心这可能是 Netbeans IDEA 的错误，但我不确定。
xml映射如下：
<web-app version="3.0" xmlns="http://java.sun.com/xml/ns/javaee" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd">
<filter>
<filter-name>FiltroLoggingFumettopoli</filter-name>
<filter-class>Filtri.FiltroLoggingFumettopoli</filter-class>
</filter>
<filter-mapping>
<filter-name>FiltroLoggingFumettopoli</filter-name>
<url-pattern>/*</url-pattern>
<dispatcher>FORWARD</dispatcher>
</filter-mapping>
<filter>
<filter-name>FiltroLogin</filter-name>
<filter-class>Filtri.FiltroLogin</filter-class>
</filter>
<filter-mapping>
<filter-name>FiltroLogin</filter-name>
<url-pattern>/Registrato/*</url-pattern>
<servlet-name>IlMioConto</servlet-name>
<servlet-name>Vendi</servlet-name>
<dispatcher>REQUEST</dispatcher>
</filter-mapping>**
这是在日志文件中进行日志记录的第一个过滤器：
private void doBeforeProcessing(ServletRequest request, ServletResponse response)
throws IOException, ServletException {
if (debug) {
log("FiltroLoggingFumettopoli:DoBeforeProcessing");
}
HttpServletRequest httpRequest = (HttpServletRequest) request;
HttpServletResponse httpResponse = (HttpServletResponse) response;
this.log(httpRequest.getRemoteHost()+" is trying to access page: "+httpRequest.getRequestURL()+
" il "+TimeUtility.ottieniDataOra()+". "+filterConfig.getFilterName());
System.out.println("FILTRO FILE DI LOG----> LOGGING OCCURED IN LOG FILE: "
+httpRequest.getRequestURL()+" il "+TimeUtility.ottieniDataOra()+". "+filterConfig.getFilterName());
}
private void doAfterProcessing(ServletRequest request, ServletResponse response)
throws IOException, ServletException {
if (debug) {
log("FiltroLoggingFumettopoli:DoAfterProcessing");
}
}
public void doFilter(ServletRequest request, ServletResponse response,
FilterChain chain)
throws IOException, ServletException {
doBeforeProcessing(request, response);
Throwable problem = null;
try {
chain.doFilter(request, response);
} catch (Throwable t) {
problem = t;
t.printStackTrace();
}
doAfterProcessing(request, response);
if (problem != null) {
if (problem instanceof ServletException) {
throw (ServletException) problem;
}
if (problem instanceof IOException) {
throw (IOException) problem;
}
sendProcessingError(problem, response);
}
}
这是一个过滤器，它检查是否是授权用户想要访问包含在 Registrato 文件夹中的资源，以及一些 servlet：
public class FiltroLogin implements Filter
{
private FilterConfig filterConfig = null;
public void init(FilterConfig filterConfig)
{
this.filterConfig = filterConfig;
}
public void doFilter(ServletRequest request,ServletResponse response,
FilterChain chain) throws IOException, ServletException
{
HttpServletRequest httpRequest = (HttpServletRequest) request;
HttpServletResponse httpResponse = (HttpServletResponse) response;
HttpSession sessione = httpRequest.getSession();
ServletContext sc = filterConfig.getServletContext();
String filterName = filterConfig.getFilterName();
String servletPath = "Servlet path: " + httpRequest.getServletPath();
String url ="";
Utente user = null;
user = (Utente) sessione.getAttribute("utente");
if(user == null){
Cookie[] cookies =httpRequest.getCookies();
String email = CookieUtility.ottieniValoreCookie(cookies, "userCookie");
if(email.equalsIgnoreCase("")){
System.out.println("FILTRO LOGIN----->NESSUN COOKIE TROVATO!");
System.out.println("FILTRO LOGIN----->SERVLET CONTEXT: "+sc.getContextPath());
url ="/MostraInserzioni";
httpResponse.sendRedirect(sc.getContextPath()+url);
return;
}
else{
System.out.println("FILTRO LOGIN----->COOKIE TROVATO: "+email);
user = UtenteSql.cercaUtente(email);
System.out.println("FILTRO LOGIN----->UTENTE TROVATO: "+user.getUsername());
sessione.setAttribute("utente", user);
String salutoUtente = "Benvenuto "+user.getNome();
sessione.setAttribute("messaggio", salutoUtente);
}
}
else
System.out.println("FILTRO LOGIN----->USER FOUND: "+user.getUsername());
sc.log(httpRequest.getRemoteHost()+" cerca di accedere alla risorsa: "+httpRequest.getRequestURL()+
" il "+TimeUtility.ottieniDataOra()+". "+filterConfig.getFilterName());
System.out.println("FILTRO FILE DI LOG----> LOGGING OCCURED IN LOG FILE: "
+httpRequest.getRequestURL()+" il "+TimeUtility.ottieniDataOra()+". "+filterConfig.getFilterName());
chain.doFilter(request, response);
}
public void destroy()
{
filterConfig = null;
}
}