YiBoRequestDirector.java 文件源码

/**
 * Execute request and retry in case of a recoverable I/O failure
 */
private HttpResponse tryExecute(
        final RoutedRequest req, final HttpContext context) throws HttpException, IOException {
    RequestWrapper wrapper = req.getRequest();
    HttpRoute route = req.getRoute();
    HttpResponse response = null;

    Exception retryReason = null;
    for (;;) {
        // Increment total exec count (with redirects)
        execCount++;
        // Increment exec count for this particular request
        wrapper.incrementExecCount();
        if (!wrapper.isRepeatable()) {
            if (Constants.DEBUG) {
                logger.debug("Cannot retry non-repeatable request");
            }
            if (retryReason != null) {
                throw new NonRepeatableRequestException("Cannot retry request " +
                    "with a non-repeatable request entity.  The cause lists the " +
                    "reason the original request failed." + retryReason);
            } else {
                throw new NonRepeatableRequestException("Cannot retry request " +
                        "with a non-repeatable request entity.");
            }
        }

        try {
            if (!managedConn.isOpen()) {
                // If we have a direct route to the target host
                // just re-open connection and re-try the request
                if (!route.isTunnelled()) {
                    if (Constants.DEBUG) {
                        logger.debug("Reopening the direct connection.");
                    }
                    managedConn.open(route, context, params);
                } else {
                    // otherwise give up
                    if (Constants.DEBUG) {
                        logger.debug("Proxied connection. Need to start over.");
                    }
                    break;
                }
            }

            if (Constants.DEBUG) {
                logger.debug("Attempt {} to execute request", execCount);
            }
            response = requestExec.execute(wrapper, managedConn, context);
            break;

        } catch (IOException ex) {
            if (Constants.DEBUG) {
                logger.debug("Closing the connection.");
            }
            try {
                managedConn.close();
            } catch (IOException ignore) {
            }
            if (retryHandler.retryRequest(ex, wrapper.getExecCount(), context)) {
                if (Constants.DEBUG) {
                    logger.debug("I/O exception ({}) caught when processing request: {}",
                            ex.getClass().getName(), ex.getMessage());
                    logger.debug(ex.getMessage(), ex);
                    logger.debug("Retrying request");
                }
                retryReason = ex;
            } else {
                throw ex;
            }
        }
    }
    return response;
}