How to use org.apache.shiro.web.util

public static ServletRequest getRequest(Object requestPairSource) {
  if (requestPairSource instanceof RequestPairSource) {
    return ((RequestPairSource) requestPairSource).getServletRequest();
  }
  return null;
}

public static ServletResponse getResponse(Object requestPairSource) {
  if (requestPairSource instanceof RequestPairSource) {
    return ((RequestPairSource) requestPairSource).getServletResponse();
  }
  return null;
}

/**
 * Create a new RedirectView with the given URL.
 * <p>The given URL will be considered as relative to the web server,
 * not as relative to the current ServletContext.
 *
 * @param url the URL to redirect to
 * @see #RedirectView(String, boolean)
 */
public RedirectView(String url) {
  setUrl(url);
}

  /**
   * Merely returns
   * <code>WebUtils.{@link org.apache.shiro.web.util.WebUtils#getPathWithinApplication(javax.servlet.http.HttpServletRequest) getPathWithinApplication(request)}</code>
   * and can be overridden by subclasses for custom request-to-application-path resolution behavior.
   *
   * @param request the incoming {@code ServletRequest}
   * @return the request's path within the appliation.
   */
  protected String getPathWithinApplication(ServletRequest request) {
    return WebUtils.getPathWithinApplication(WebUtils.toHttp(request));
  }
}

/**
 * Redirects the current request to a new URL based on the given parameters.
 *
 * @param request          the servlet request.
 * @param response         the servlet response.
 * @param url              the URL to redirect the user to.
 * @param queryParams      a map of parameters that should be set as request parameters for the new request.
 * @param contextRelative  true if the URL is relative to the servlet context path, or false if the URL is absolute.
 * @param http10Compatible whether to stay compatible with HTTP 1.0 clients.
 * @throws java.io.IOException if thrown by response methods.
 */
public static void issueRedirect(ServletRequest request, ServletResponse response, String url, Map queryParams, boolean contextRelative, boolean http10Compatible) throws IOException {
  RedirectView view = new RedirectView(url, contextRelative, http10Compatible);
  view.renderMergedOutputModel(queryParams, toHttp(request), toHttp(response));
}

/**
 * Redirects the current request to a new URL based on the given parameters and default values
 * for unspecified parameters.
 *
 * @param request  the servlet request.
 * @param response the servlet response.
 * @param url      the URL to redirect the user to.
 * @throws java.io.IOException if thrown by response methods.
 */
public static void issueRedirect(ServletRequest request, ServletResponse response, String url) throws IOException {
  issueRedirect(request, response, url, null, true, true);
}

public static HttpServletRequest getHttpRequest(Object requestPairSource) {
  ServletRequest request = getRequest(requestPairSource);
  if (request instanceof HttpServletRequest) {
    return (HttpServletRequest) request;
  }
  return null;
}

public static HttpServletResponse getHttpResponse(Object requestPairSource) {
  ServletResponse response = getResponse(requestPairSource);
  if (response instanceof HttpServletResponse) {
    return (HttpServletResponse) response;
  }
  return null;
}

public static boolean isWeb(Object requestPairSource) {
  return requestPairSource instanceof RequestPairSource && isWeb((RequestPairSource) requestPairSource);
}

public static boolean isHttp(Object requestPairSource) {
  return requestPairSource instanceof RequestPairSource && isHttp((RequestPairSource) requestPairSource);
}

/**
 * Convenience method merely delegates to
 * {@link WebUtils#saveRequest(javax.servlet.ServletRequest) WebUtils.saveRequest(request)} to save the request
 * state for reuse later.  This is mostly used to retain user request state when a redirect is issued to
 * return the user to their originally requested url/resource.
 * <p/>
 * If you need to save and then immediately redirect the user to login, consider using
 * {@link #saveRequestAndRedirectToLogin(javax.servlet.ServletRequest, javax.servlet.ServletResponse)
 * saveRequestAndRedirectToLogin(request,response)} directly.
 *
 * @param request the incoming ServletRequest to save for re-use later (for example, after a redirect).
 */
protected void saveRequest(ServletRequest request) {
  WebUtils.saveRequest(request);
}

private static boolean isWeb(RequestPairSource source) {
  ServletRequest request = source.getServletRequest();
  ServletResponse response = source.getServletResponse();
  return request != null && response != null;
}

/**
 * Returns {@code true} if a session is allowed to be created for a subject-associated request, {@code false}
 * otherwise.
 * <p/>
 * <b>This method exists for Shiro's internal framework needs and should never be called by Shiro end-users.  It
 * could be changed/removed at any time.</b>
 *
 * @param requestPairSource a {@link RequestPairSource} instance, almost always a
 *                          {@link org.apache.shiro.web.subject.WebSubject WebSubject} instance.
 * @return {@code true} if a session is allowed to be created for a subject-associated request, {@code false}
 *         otherwise.
 */
public static boolean _isSessionCreationEnabled(Object requestPairSource) {
  if (requestPairSource instanceof RequestPairSource) {
    RequestPairSource source = (RequestPairSource) requestPairSource;
    return _isSessionCreationEnabled(source.getServletRequest());
  }
  return true; //by default
}

/**
 * Normalize a relative URI path that may have relative values ("/./",
 * "/../", and so on ) it it.  <strong>WARNING</strong> - This method is
 * useful only for normalizing application-generated paths.  It does not
 * try to perform security checks for malicious input.
 * Normalize operations were was happily taken from org.apache.catalina.util.RequestUtil in
 * Tomcat trunk, r939305
 *
 * @param path Relative path to be normalized
 * @return normalized path
 */
public static String normalize(String path) {
  return normalize(path, true);
}

/**
 * Find the Shiro {@link WebEnvironment} for this web application, which is typically loaded via
 * {@link org.apache.shiro.web.env.EnvironmentLoaderListener}.
 * <p/>
 * This implementation rethrows an exception that happened on environment startup to differentiate between a failed
 * environment startup and no environment at all.
 *
 * @param sc ServletContext to find the web application context for
 * @return the root WebApplicationContext for this web app, or <code>null</code> if none
 * @see org.apache.shiro.web.env.EnvironmentLoader#ENVIRONMENT_ATTRIBUTE_KEY
 * @since 1.2
 */
public static WebEnvironment getWebEnvironment(ServletContext sc) {
  return getWebEnvironment(sc, EnvironmentLoader.ENVIRONMENT_ATTRIBUTE_KEY);
}

/**
 * Returns the context path within the application based on the specified <code>request</code>.
 * <p/>
 * This implementation merely delegates to
 * {@link WebUtils#getPathWithinApplication(javax.servlet.http.HttpServletRequest) WebUtils.getPathWithinApplication(request)},
 * but can be overridden by subclasses for custom logic.
 *
 * @param request the incoming <code>ServletRequest</code>
 * @return the context path within the application.
 */
protected String getPathWithinApplication(ServletRequest request) {
  return WebUtils.getPathWithinApplication(WebUtils.toHttp(request));
}

/**
 * Issues an HTTP redirect to the specified URL after subject logout.  This implementation simply calls
 * {@code WebUtils.}{@link WebUtils#issueRedirect(javax.servlet.ServletRequest, javax.servlet.ServletResponse, String) issueRedirect(request,response,redirectUrl)}.
 *
 * @param request  the incoming Servlet request
 * @param response the outgoing Servlet response
 * @param redirectUrl the URL to where the browser will be redirected immediately after Subject logout.
 * @throws Exception if there is any error.
 */
protected void issueRedirect(ServletRequest request, ServletResponse response, String redirectUrl) throws Exception {
  WebUtils.issueRedirect(request, response, redirectUrl);
}

private static boolean isHttp(RequestPairSource source) {
  ServletRequest request = source.getServletRequest();
  ServletResponse response = source.getServletResponse();
  return request instanceof HttpServletRequest && response instanceof HttpServletResponse;
}

/**
 * Redirects the current request to a new URL based on the given parameters and default values
 * for unspecified parameters.
 *
 * @param request     the servlet request.
 * @param response    the servlet response.
 * @param url         the URL to redirect the user to.
 * @param queryParams a map of parameters that should be set as request parameters for the new request.
 * @throws java.io.IOException if thrown by response methods.
 */
public static void issueRedirect(ServletRequest request, ServletResponse response, String url, Map queryParams) throws IOException {
  issueRedirect(request, response, url, queryParams, true, true);
}

/**
 * Redirects the current request to a new URL based on the given parameters and default values
 * for unspecified parameters.
 *
 * @param request         the servlet request.
 * @param response        the servlet response.
 * @param url             the URL to redirect the user to.
 * @param queryParams     a map of parameters that should be set as request parameters for the new request.
 * @param contextRelative true if the URL is relative to the servlet context path, or false if the URL is absolute.
 * @throws java.io.IOException if thrown by response methods.
 */
public static void issueRedirect(ServletRequest request, ServletResponse response, String url, Map queryParams, boolean contextRelative) throws IOException {
  issueRedirect(request, response, url, queryParams, contextRelative, true);
}