protected void waitForSlingStartup()

in src/main/java/org/apache/sling/commons/testing/integration/HttpTestBase.java [212:284]
60 lines of code
12 McCabe index (conditional complexity)

    protected void waitForSlingStartup() throws Exception {
        // Use a static flag to make sure this runs only once in our test suite
        // we must synchronize on this if we don't 2 threads could enter the check concurrently
        // which would leave to random results.
        synchronized(startupCheckLock) {
            if (slingStartupOk != null) {
                if(slingStartupOk) {
                    return;
                }
                fail("Sling services not available. Already checked in earlier tests.");
            }
            if ( System.getProperty(PROPERTY_SKIP_STARTUP_CHECK) != null ) {
                slingStartupOk = true;
                return;
            }
            slingStartupOk = false;
        }

        System.err.println("Checking if the required Sling services are started (timeout " + READY_TIMEOUT_SECONDS + " seconds)...");
        System.err.println(
                "(base URLs=" + HTTP_BASE_URL + " and " + WEBDAV_BASE_URL 
                + "; servlet context="+ SERVLET_CONTEXT
                + "; readiness type=" + readinessCheckExtension + " : " + readinessCheckContentTypePrefix
                );

        // Try creating a node on server, every 500msec, until ok, with timeout
        final List<String> exceptionMessages = new LinkedList<String>();
        final long maxMsecToWait = READY_TIMEOUT_SECONDS * 1000L;
        final long startupTime = System.currentTimeMillis();
        String lastException = "";
        int nTimesOk = 0;
        
        // Wait until slingServerReady returns true this many times,
        // as in some cases more initializations might take place after
        // this returns true
        final int MIN_TIMES_OK = 4;
        
        while(!slingStartupOk && (System.currentTimeMillis() < startupTime + maxMsecToWait) ) {
            try {
                if(slingServerReady()) {
                    nTimesOk++;
                    if(nTimesOk >= MIN_TIMES_OK) {
                        slingStartupOk = true;
                        break;
                    }
                } else {
                    nTimesOk = 0;
                }
            } catch(Exception e) {
                nTimesOk = 0;
                final String newX = e.toString();
                if(!lastException.equals(newX)) {
                    exceptionMessages.add(newX);
                }
                lastException = newX;
            }
            Thread.sleep(500L);
        }

        if(slingStartupOk) {
            log.info("Sling server found ready after {} msec", System.currentTimeMillis() - startupTime);
        } else {
            StringBuffer msg = new StringBuffer("Server does not seem to be ready, after ");
            msg.append(maxMsecToWait).append(" msec, got the following ").append(exceptionMessages.size()).append(" Exceptions:");
            for (String e: exceptionMessages) {
                msg.append(e).append("\n");
            }
            System.err.println(msg);
            fail(msg.toString());
        }

        System.err.println("Sling services seem to be started, continuing with integration tests.");
    }