javax.ws.rs.core.Response.Status#SERVICE_UNAVAILABLE源码实例Demo

/**
 * Check if the cluster exists and redirect the call to the owning cluster
 *
 * @param cluster
 *            Cluster name
 * @throws Exception
 *             In case the redirect happens
 */
protected void validateClusterOwnership(String cluster) throws WebApplicationException {
    try {
        ClusterData differentClusterData = getClusterDataIfDifferentCluster(pulsar(), cluster, clientAppId()).get();
        if (differentClusterData != null) {
            URI redirect = getRedirectionUrl(differentClusterData);
            // redirect to the cluster requested
            if (log.isDebugEnabled()) {
                log.debug("[{}] Redirecting the rest call to {}: cluster={}", clientAppId(), redirect, cluster);

            }
            throw new WebApplicationException(Response.temporaryRedirect(redirect).build());
        }
    } catch (WebApplicationException wae) {
        throw wae;
    } catch (Exception e) {
        if (e.getCause() instanceof WebApplicationException) {
            throw (WebApplicationException) e.getCause();
        }
        throw new RestException(Status.SERVICE_UNAVAILABLE, String
                .format("Failed to validate Cluster configuration : cluster=%s  emsg=%s", cluster, e.getMessage()));
    }

}
 

@Override
public void doFilter(
    final ServletRequest request, final ServletResponse response, final FilterChain chain
) throws IOException, ServletException {
    if (!stopping.get()) {
        chain.doFilter(request, response);
        return;
    }

    final HttpServletResponse httpResponse = (HttpServletResponse) response;

    final InternalErrorMessage info =
        new InternalErrorMessage("Heroic is shutting down", Status.SERVICE_UNAVAILABLE);

    httpResponse.setStatus(Status.SERVICE_UNAVAILABLE.getStatusCode());
    httpResponse.setContentType(CONTENT_TYPE);

    // intercept request
    try (final ByteArrayOutputStream output = new ByteArrayOutputStream(4096)) {
        final OutputStreamWriter writer = new OutputStreamWriter(output, Charsets.UTF_8);
        mapper.writeValue(writer, info);
        response.setContentLength(output.size());
        output.writeTo(httpResponse.getOutputStream());
    }
}
 

@GET
@Path("ping")
public Response ping() {
    Service.Status status = enclave.status();
    Status httpStatus;
    if (status == Service.Status.STARTED) {
        httpStatus = Status.OK;
    } else {
        httpStatus = Status.SERVICE_UNAVAILABLE;
    }
    return Response.status(httpStatus).entity(status.name()).build();
}
 

@PostMapping(path = "/sayhello/{name}")
public String sayHello(@PathVariable("name") String name) {
  if ("exception".equals(name)) {
    throw new InvocationException(Status.SERVICE_UNAVAILABLE, "");
  }
  return "hello " + name;
}
 

@GetMapping(path = "/retrySuccess")
public int retrySuccess(@RequestParam("a") int a, @RequestParam("b") int b) {
  if (firstInovcation.getAndDecrement() > 0) {
    throw new InvocationException(Status.SERVICE_UNAVAILABLE, "try again later.");
  }
  return a + b;
}
 

private void ensureStatusUp() {
  if (scbEngine == null) {
    if (SCBEngine.getInstance() == null) {
      String message =
          "The request is rejected. Cannot process the request due to SCBEngine not ready.";
      LOGGER.warn(message);
      throw new InvocationException(Status.SERVICE_UNAVAILABLE, message);
    }

    this.scbEngine = SCBEngine.getInstance();
    this.appId = scbEngine.parseAppId(microserviceName);
  }

  scbEngine.ensureStatusUp();
}
 

public void ensureStatusUp() {
  SCBStatus currentStatus = getStatus();
  if (!SCBStatus.UP.equals(currentStatus)) {
    String message =
        "The request is rejected. Cannot process the request due to STATUS = " + currentStatus;
    LOGGER.warn(message);
    throw new InvocationException(Status.SERVICE_UNAVAILABLE, message);
  }
}
 

/**
 * Find next broker url in round-robin
 *
 * @return
 */
LoadManagerReport nextBroker() {
    List<LoadManagerReport> availableBrokers = zkCache.getAvailableBrokers();

    if (availableBrokers.isEmpty()) {
        throw new RestException(Status.SERVICE_UNAVAILABLE, "No active broker is available");
    } else {
        int brokersCount = availableBrokers.size();
        int nextIdx = signSafeMod(counter.getAndIncrement(), brokersCount);
        return availableBrokers.get(nextIdx);
    }
}
 

protected ProxyService proxyService() {
    if (service == null) {
        service = (ProxyService) servletContext.getAttribute(ATTRIBUTE_PULSAR_PROXY_NAME);
        if (service == null) {
            throw new RestException(Status.SERVICE_UNAVAILABLE, "Proxy service is not initialized");
        }
    }
    return service;
}
 

@Override
public Response toResponse(UncategorizedMongoDbException exception) {
    Status errorStatus = Status.SERVICE_UNAVAILABLE;
    LOG.error("Could not access database", exception);
    return Response
            .status(errorStatus)
            .entity(new ErrorResponse(errorStatus.getStatusCode(), errorStatus.getReasonPhrase(),
                    "Could not access database:" + exception.getMessage())).build();
}
 

private void throwStateStoreUnvailableResponse() {
    throw new RestException(Status.SERVICE_UNAVAILABLE,
            "State storage client is not done initializing. " + "Please try again in a little while.");
}
 

@GET
@Path("localnode/health")
@Produces(MediaType.TEXT_PLAIN)
public String getLocalNodeHealth() throws MalformedObjectNameException
{
    // Local service only - not enabled when running on top of Tomcat & co.
    if (n == null)
    {
        throw new ErrorDto("can only retrieve local node health when the web app runs on top of JQM", "", 7, Status.BAD_REQUEST);
    }
    if (n.getJmxServerPort() == null || n.getJmxServerPort() == 0)
    {
        throw new ErrorDto("JMX is not enabled on this server", "", 8, Status.BAD_REQUEST);
    }

    // Connect to JMX server
    MBeanServer server = ManagementFactory.getPlatformMBeanServer();
    ObjectName nodeBean = new ObjectName("com.enioka.jqm:type=Node,name=" + n.getName());
    Set<ObjectName> names = server.queryNames(nodeBean, null);
    if (names.isEmpty())
    {
        throw new ErrorDto("could not find the JMX Mbean of the local JQM node", "", 8, Status.INTERNAL_SERVER_ERROR);
    }
    ObjectName localNodeBean = names.iterator().next();

    // Query bean
    Object result;
    try
    {
        result = server.getAttribute(localNodeBean, "AllPollersPolling");
    }
    catch (Exception e)
    {
        throw new ErrorDto("Issue when querying JMX server", 12, e, Status.INTERNAL_SERVER_ERROR);
    }
    if (!(result instanceof Boolean))
    {
        throw new ErrorDto("JMX bean answered with wrong datatype - answer was " + result.toString(), "", 9,
                Status.INTERNAL_SERVER_ERROR);
    }

    // Analyze output
    boolean res = (Boolean) result;
    if (!res)
    {
        throw new ErrorDto("JQM node has is not working as expected", "", 11, Status.SERVICE_UNAVAILABLE);
    }

    return "Pollers are polling";
}
 

/**
 * Creates a builder for a unavailable service
 * 
 * @return the exception builder
 */
public static ExceptionBuilder unavailable() {
    return new ExceptionBuilder(Status.SERVICE_UNAVAILABLE);
}