Class PersistentValve

java/org/apache/catalina/valves/PersistentValve.java:73–546

Valve that implements per-request session persistence. It is intended to be used with non-sticky load-balancers and a PersistentManager. The Valve works by loading the session from the Store at the start of the request, the request then updates the session as required and the Valve saves the session

 * </ul>
 */
public class PersistentValve extends ValveBase {

    private static final Log log = LogFactory.getLog(PersistentValve.class);

    // Saves a couple of calls to getClassLoader() on every request. Under high
    // load these calls took just long enough to appear as a hot spot (although
    // a very minor one) in a profiler.
    private static final ClassLoader MY_CLASSLOADER = PersistentValve.class.getClassLoader();

    private volatile boolean clBindRequired;

    /**
     * Regular expression pattern used to filter requests that should bypass session persistence.
     */
    protected Pattern filter = null;

    private final ConcurrentMap<String,UsageCountingSemaphore> sessionToSemaphoreMap = new ConcurrentHashMap<>();

    private boolean semaphoreFairness = true;

    private boolean semaphoreBlockOnAcquire = true;

    private boolean semaphoreAcquireUninterruptibly = true;


    /**
     * Constructs a new PersistentValve instance.
     */
    public PersistentValve() {
        super(true);
    }


    @Override
    public void setContainer(Container container) {
        super.setContainer(container);
        clBindRequired = container instanceof Engine || container instanceof Host;
    }


    @Override
    public void invoke(Request request, Response response) throws IOException, ServletException {

        // request without session
        if (isRequestWithoutSession(request.getDecodedRequestURI())) {
            if (containerLog.isTraceEnabled()) {
                containerLog.trace(sm.getString("persistentValve.requestIgnore", request.getDecodedRequestURI()));
            }
            getNext().invoke(request, response);
            return;
        } else if (containerLog.isTraceEnabled()) {
            containerLog.trace(sm.getString("persistentValve.requestProcess", request.getDecodedRequestURI()));
        }

        // Select the Context to be used for this Request
        Context context = request.getContext();
        if (context == null) {
            response.sendError(HttpServletResponse.SC_INTERNAL_SERVER_ERROR, sm.getString("standardHost.noContext"));