Example usage for javax.servlet UnavailableException UnavailableException

Introduction

In this page you can find the example usage for javax.servlet UnavailableException UnavailableException.

Prototype

public UnavailableException(String msg, int seconds) 

Source Link

Document

Constructs a new exception with a descriptive message indicating that the servlet is temporarily unavailable and giving an estimate of how long it will be unavailable.

Usage

From source file:org.eclipse.gyrex.http.jetty.internal.app.ApplicationDelegateHandler.java

@Override
public void doScope(final String target, final Request baseRequest, final HttpServletRequest request,
        final HttpServletResponse response) throws IOException, ServletException {

    /*/* w w  w .j  a va  2 s. c o m*/
     * This scope implementation is different. We delegate to
     * the application immediately. The assumption is, the context,
     *  path info and session has been properly set up by scoping
     * from previous handlers (scopes).
     *
     * The next scope would be the servlet handler which handles
     * servlets registered via IApplicationContext. However, the
     * ServletHandler already modifies the scope by setting
     * a servlet path and path info as of the found servlet.
     * This is wrong when calling Application#handleRequest.
     *
     * It's completely up to the Application if the ServletHandler
     * should be called or not. It does so via calling the
     * IApplicationContext method. This is implemented in this class
     * as well (handleApplicationRequest) and continues with the next
     * scope.
     */

    // delegated to the application
    // the application may delegate back to us via ApplicationContext
    try {
        final Application application = applicationHandler.getApplication();

        // setup MDC
        setupMdc(application, request);

        // check application status
        final IStatus status = application.getStatus();
        if (!status.isOK()) {
            // abort request processing
            final String message = StringUtils.defaultIfEmpty(status.getMessage(), "Application not ready.");
            // we convert it into UnavailableException
            if (Platform.inDebugMode()) {
                LOG.warn("Application '{}' returned a not-ok status: {}",
                        new Object[] { application.getId(), status });
                throw new UnavailableException(message, 5);
            } else
                throw new UnavailableException(message, 30); // TODO make configurable
        }

        // route to application
        if (JettyDebug.handlers) {
            LOG.debug("routing request to application {}", application);
        }
        application.handleRequest(request, response);
    } catch (final IOException e) {
        if (Platform.inDebugMode()) {
            LOG.warn("Caught IOException while processing request '{}': {}",
                    new Object[] { request, e.getMessage(), e });
        }
        throw e;
    } catch (final ApplicationException e) {
        // handle ApplicationException
        if (e.getStatus() == HttpStatus.SERVICE_UNAVAILABLE_503) {
            // we convert it into UnavailableException
            if (Platform.inDebugMode()) {
                LOG.warn("Caught ApplicationException while processing request '{}': {}",
                        new Object[] { request, e.getMessage(), e });
                throw new UnavailableException(e.getMessage(), 5);
            } else
                throw new UnavailableException(e.getMessage(), 30); // TODO make configurable
        } else {
            if (Platform.inDebugMode()) {
                LOG.warn("Caught ApplicationException while processing request '{}': {}",
                        new Object[] { request, e.getMessage(), e });
                response.sendError(e.getStatus(), e.getMessage());
            } else {
                response.sendError(e.getStatus());
            }
        }
    } catch (final IllegalStateException e) {
        // IllegalStateException are typically used in Gyrex to indicate that something isn't ready
        // we convert it into UnavailableException to allow recovering on a dynamic platform
        if (Platform.inDebugMode()) {
            LOG.warn("Caught IllegalStateException while processing request '{}': {}",
                    new Object[] { request, e.getMessage(), e });
            throw new UnavailableException(e.getMessage(), 5);
        } else
            throw new UnavailableException(e.getMessage(), 30); // TODO make configurable
    } catch (final RuntimeException e) {
        if (Platform.inDebugMode()) {
            LOG.warn("Caught RuntimeException while processing request '{}': {}",
                    new Object[] { request, e.getMessage(), e });
        }
        throw e;
    } finally {
        // clear the MDC
        clearMdc();
    }

    // mark the request handled (if this point is reached)
    baseRequest.setHandled(true);
}

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