從servlet過濾器（通過AJAX客戶端 - 服務器連接）重定向Web客戶端

Question

我正在使用JAASRealm身份驗證（在tomcat 7中）執行Web。 這是servlet的一個過濾器：

private String loginPage = "welcome.jsp"; 

@Override 
public void doFilter(ServletRequest request, ServletResponse response, 
     FilterChain filterChain) throws IOException, ServletException { 

    if ((request instanceof HttpServletRequest) && (response instanceof HttpServletResponse)) { 
     HttpServletRequest httpServletRequest = (HttpServletRequest) request; 
     HttpServletResponse httpServletResponse = (HttpServletResponse) response; 
     if (httpServletRequest.getUserPrincipal() == null) { 
      // User is not logged in, redirect to login page. 
      httpServletRequest.setAttribute("from", httpServletRequest.getRequestURI()); 
      httpServletResponse.sendRedirect(loginPage); 
     } 
     else { 
      filterChain.doFilter(request, response); 
     } 
    } 
} 

而且我已經在web.xml中聲明它

<filter> 
    <filter-name>login-filter</filter-name> 
    <filter-class>LoginFilter</filter-class> 
</filter> 
<filter-mapping> 
    <filter-name>login-filter</filter-name> 
    <url-pattern>/sampleServlet</url-pattern> 
</filter-mapping> 

我的問題是，當我沒有授權，但我通過AJAX調用servlet，這過濾器行不起作用

httpServletResponse.sendRedirect(loginPage); 

所以，我沒有收到任何數據，我沒有重定向到登錄頁面。在這種情況下我能做些什麼？

Answer 1

這裏是我送過濾AJAX請求......

AJAX代碼（jQuery的）

$.ajax({ 
    type: 'post', 
    url: '/signMeInServlet', 
    data: { 
     'name': name, 
     'pass': passW, 
     }, 
    dataType: 'json', 
    success: processSignInReturnMethod, 
    error: function (xhr, ajaxOptions, thrownError){ 
     if (thrownError.redirect.length) { 
      window.location.replace(thrownError.redirect); 
     } else { 
      alert('There was an error processing your request, please try again'); 
     } 
    } 
}); 

相關過濾代碼時

// Rest of your Filter processing and logic here, once you know you want 
// to redirect, use the below code, which works for both AJAX and regualar 
// requests 

HttpServletRequest hreq = (HttpServletRequest) request; 
String redirectUrl = "/redirected.jsp"; 

if (hreq.getHeader("x-requested-with") != null && 
     hreq.getHeader("x-requested-with").equalsIgnoreCase("XMLHttpRequest")) { 

    // Set up your response here 
    HttpServletResponse hres = (HttpServletResponse) response; 
    hres.setContentType("text/json; charset=UTF-8"); 

    PrintWriter out = hres.getWriter(); 

    String json = "[{\"redirect\":\"" + redirectUrl + "\"}]"; 

    out.write(json); 
    out.flush(); 
    out.close(); 

} else { 

    ((HttpServletResponse)response).sendRedirect(redirectUrl); 
} 

Answer 2

我解決了這個問題，但重新定向不像我想的那樣。 我在servler過濾器使用此行

httpServletResponse.setStatus(HttpServletResponse.SC_MOVED_PERMANENTLY); 

，並在客戶端，使用Ajax請求我抓住這個狀態，然後我做的重定向

var fAjaxRedirect = function(response, textStatus) { 
    /* 301 is the code SC_MOVED_PERMANENTLY */ 
    if (response.status == 301) { 
     location.reload(); //or location.href = 'xxxx.jsp'; 
}}; 

    $.ajaxSetup({ 
     scriptCharset: "utf-8", 
     contentType: "application/x-www-form-urlencoded; charset=UTF-8" 
    }); 
    $.ajax({ 
     type: "POST", 
     url: "myServlet", 
     complete: fAjaxRedirect, 
     success: function(val) { 
      //something here 
     } 
    }); 

但是，使用這種方式做，是做頁面重定向的客戶端，我想從服務器端執行，而不依賴於客戶端。

Answer 3

我試圖使用一些優雅的解決方案，但沒有工作。我發現這個人吃了primefaces論壇，並且還在純JSF應用程序上工作。

我使用的網頁過濾：

public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException { 
    HttpServletRequest httpRequest = (HttpServletRequest) request; 
    HttpServletResponse httpResponse = (HttpServletResponse) response; 

    if(!identity.isLoggedIn()){ 
     if (isAjax(httpRequest)) { 
      httpResponse.getWriter().print(xmlPartialRedirectToPage(httpRequest, "/login.xhtml")); 
      httpResponse.flushBuffer();     
     }else{ 
      httpResponse.sendRedirect(httpRequest.getContextPath() + "/login.xhtml"); 
     } 
    }else{ 
     chain.doFilter(request, response); 
    } 
} 

private String xmlPartialRedirectToPage(HttpServletRequest request, String page) { 
    StringBuilder sb = new StringBuilder(); 
    sb.append("<?xml version='1.0' encoding='UTF-8'?>"); 
    sb.append("<partial-response><redirect url=\"").append(request.getContextPath()).append(request.getServletPath()).append(page).append("\"/></partial-response>"); 
    return sb.toString(); 
} 

private boolean isAjax(HttpServletRequest request) { 
    return "XMLHttpRequest".equals(request.getHeader("X-Requested-With")); 
}