Create PentahoHttpResource extends HttpResource override exists() …

[boehm-gipmbh]

… getLastModifiedTime() using GET to Keycloak and use in blueprint.xml
This is a well working fix while introducing a PentahoHttpResource.class extends org.opensaml.util.resource.HttpResource.
HttpResource from org.opensaml.util.resource.HttpResource uses HEAD-Request without authentication, which is forbidden by Keycloak at least in version 25.
Both methods using HEAD calls to KC25 are overidden and use unauthenticated GET calls instead to KC25 which are still allowed against KC25 for existent check.

[jonjarvis]

I was wondering why this stopped working, but hadn't looked into it, simply using the filesystem based files instead. What is interesting is the code from the original HTTPResource has a fallback method to use GET instead of HEAD:

try {
            HttpResponse httpResponse = httpClient.[execute](http://www.java2s.com/example/java-src/pkg/org/apache/http/client/httpclient-769b4.html#632f2bdb2540939e7f502588aacc6f91)(httpRequest);
            int statusCode = httpResponse.getStatusLine().getStatusCode();
            httpRequest.[abort](http://www.java2s.com/example/java-src/pkg/org/apache/http/client/methods/httpurirequest-8fa0f.html#d82bdee79ee610d91ec124e0f322800a)();

            if (statusCode == HttpStatus.SC_METHOD_NOT_ALLOWED) {
                log.debug(resourceUrl + " does not support HEAD requests, falling back to GET request");
                httpRequest = buildGetRequest();
                httpResponse = httpClient.[execute](http://www.java2s.com/example/java-src/pkg/org/apache/http/client/httpclient-769b4.html#632f2bdb2540939e7f502588aacc6f91)(httpRequest);
                statusCode = httpResponse.getStatusLine().getStatusCode();
                httpRequest.[abort](http://www.java2s.com/example/java-src/pkg/org/apache/http/client/methods/httpurirequest-8fa0f.html#d82bdee79ee610d91ec124e0f322800a)();
            }

            if (statusCode != HttpStatus.SC_OK) {
                return false;
            }

[boehm-gipmbh]

Dear Jonathan,
I agree, this code would look nice, but it seems this class is not the one used in the flow.
In my environment the org.opensaml.util.resource.HttpResource of <dependency.opensaml.openws.version>1.5.6</dependency.opensaml.openws.version>
is used, which is coded

 public boolean exists() throws ResourceException {
        HeadMethod headMethod = new HeadMethod(resourceUrl);
        headMethod.addRequestHeader("Connection", "close");

        try {
            httpClient.executeMethod(headMethod);
            if (headMethod.getStatusCode() != HttpStatus.SC_OK) {
                return false;
            }

            return true;
        } catch (IOException e) {
            throw new ResourceException("Unable to contact resource URL: " + resourceUrl, e);
        } finally {
            headMethod.releaseConnection();
        }
    }'

indicating Resource does not exist.
The other method using HEAD-call is 
``` public DateTime getLastModifiedTime() throws ResourceException {
        HeadMethod headMethod = new HeadMethod(resourceUrl);
        headMethod.addRequestHeader("Connection", "close");

        try {
            httpClient.executeMethod(headMethod);
            if (headMethod.getStatusCode() != HttpStatus.SC_OK) {
                throw new ResourceException("Unable to retrieve resource URL " + resourceUrl
                        + ", received HTTP status code " + headMethod.getStatusCode());
            }
            Header lastModifiedHeader = headMethod.getResponseHeader("Last-Modified");
            if (lastModifiedHeader != null && !DatatypeHelper.isEmpty(lastModifiedHeader.getValue())) {
                long lastModifiedTime = DateUtil.parseDate(lastModifiedHeader.getValue()).getTime();
                return new DateTime(lastModifiedTime, ISOChronology.getInstanceUTC());
            }

            return new DateTime();
        } catch (IOException e) {
            throw new ResourceException("Unable to contact resource URL: " + resourceUrl, e);
        } catch (DateParseException e) {
            throw new ResourceException("Unable to parse last modified date for resource:" + resourceUrl, e);
        } finally {
            headMethod.releaseConnection();
        }
    }'
throwing the exception.
I believe, this is not handled as you suggest by your code fragment, at least I cannot reproduce this solution mentioned
Kind regards
Detlef