bug6060: handle BrandingConfiguration service appearance/disappearance dynamically

java/com.sap.sse.branding/src/com/sap/sse/branding/BrandingConfigurationService.java

@@ -3,8 +3,6 @@ package com.sap.sse.branding;
 import java.util.Map;
 import java.util.Optional;
 
-import javax.servlet.ServletContext;
-
 import com.sap.sse.branding.shared.BrandingConfiguration;
 
 /**
@@ -49,13 +47,6 @@ public interface BrandingConfigurationService {
      */
     String JSP_PROPERTY_NAME_PREFIX = "clientConfigurationContext";
     
-    /**
-     * Attribute name used in the {@link ServletContext}, value being a map from a pair of locale (e.g. "en") and
-     * branding ID (see {@link BrandingConfiguration#getId()}) to a map of JSP properties that can be used to set it
-     * to the {@link #JSP_PROPERTY_NAME_PREFIX} attribute in the {@link HttpServletRequest} scope.
-     */
-    String JSP_PROPERTIES_BY_LOCALE_AND_BRANDING_ID = "clientConfigurationContextsByLocaleAndBrandingId";
-    
     public static enum BrandingConfigurationProperty {
         /**
          * The name of the JSP property, appended to the value of {@link #JSP_PROPERTY_NAME_PREFIX}, that contains the brand title
@@ -134,5 +125,11 @@ public interface BrandingConfigurationService {
      * <p>
      * @param locale if present, the locale to use for the branding configuration properties, otherwise the default locale
      */
-    Map<BrandingConfigurationProperty, Object> getBrandingConfigurationPropertiesForJspContext(Optional<String> locale);
+    Map<BrandingConfigurationProperty, Object> getBrandingConfigurationProperties(Optional<String> locale);
+    
+    /**
+     * Same as {@link #getBrandingConfigurationProperties(Optional)} but returns a map where the keys are
+     * the property names as defined in {@link BrandingConfigurationProperty#getPropertyName()}.
+     */
+    Map<String, Object> getBrandingConfigurationPropertiesForJspContext(Optional<String> locale);
 }

java/com.sap.sse.branding/src/com/sap/sse/branding/ClientConfigurationListener.java

@@ -1,10 +1,7 @@
 package com.sap.sse.branding;
 
-import java.util.HashMap;
 import java.util.Map;
 import java.util.Optional;
-import java.util.concurrent.ConcurrentHashMap;
-import java.util.concurrent.ConcurrentMap;
 
 import javax.servlet.ServletContext;
 import javax.servlet.ServletRequestEvent;
@@ -12,7 +9,6 @@ import javax.servlet.http.HttpServletRequest;
 
 import com.sap.sse.branding.BrandingConfigurationService.BrandingConfigurationProperty;
 import com.sap.sse.branding.impl.Activator;
-import com.sap.sse.common.Util.Pair;
 import com.sap.sse.rest.GwtLocaleFromHttpRequestUtil;
 
 /**
@@ -71,7 +67,7 @@ public class ClientConfigurationListener implements javax.servlet.ServletRequest
      * <p>
      * 
      * The properties are constructed using
-     * {@link BrandingConfigurationService#getBrandingConfigurationPropertiesForJspContext(Optional)} with the locale as
+     * {@link BrandingConfigurationService#getBrandingConfigurationProperties(Optional)} with the locale as
      * argument, where the property names are derived from the {@link BrandingConfigurationProperty#getPropertyName()}
      * method which get appended to the {@link BrandingConfigurationService#JSP_PROPERTY_NAME_PREFIX} prefix.
      * <p>
@@ -86,37 +82,13 @@ public class ClientConfigurationListener implements javax.servlet.ServletRequest
             final String path = httpServletRequest.getServletPath();
             // populate JSP scopes (applicationScope and requestScope) only for HTML pages or "/" requests
             if (path != null && (path.endsWith("/") || path.endsWith(".html"))) {
-                final ServletContext servletContext = httpServletRequest.getServletContext();
                 Optional<String> requestLocale = GwtLocaleFromHttpRequestUtil.getLocaleFromHttpRequest(httpServletRequest);
-                final Map<String, Object> brandingProperties = getAndCacheBrandingConfigurationPropertiesFromServletContext(
-                        servletContext, requestLocale, Activator.getDefaultBrandingConfigurationService());
+                final Map<String, Object> brandingProperties = Activator.getDefaultBrandingConfigurationService().getBrandingConfigurationPropertiesForJspContext(requestLocale);
                 httpServletRequest.setAttribute(BrandingConfigurationService.JSP_PROPERTY_NAME_PREFIX, brandingProperties);
             }
         }
     }
     
-    private Map<String, Object> getAndCacheBrandingConfigurationPropertiesFromServletContext(
-            ServletContext servletContext, Optional<String> locale, BrandingConfigurationService brandingConfigurationService) {
-        @SuppressWarnings("unchecked")
-        ConcurrentMap<Pair<String, String>, Map<String, Object>> brandingProperties =
-            (ConcurrentMap<Pair<String, String>, Map<String, Object>>) servletContext.getAttribute(BrandingConfigurationService.JSP_PROPERTIES_BY_LOCALE_AND_BRANDING_ID);
-        if (brandingProperties == null) {
-            brandingProperties = new ConcurrentHashMap<>();
-            servletContext.setAttribute(BrandingConfigurationService.JSP_PROPERTIES_BY_LOCALE_AND_BRANDING_ID, brandingProperties);
-        }
-        final Pair<String, String> key = new Pair<>(locale.orElse(null),
-                brandingConfigurationService.isBrandingActive() ? brandingConfigurationService.getActiveBrandingConfiguration().getId() : null);
-        return brandingProperties.computeIfAbsent(key, k->computeBrandingConfigurationProperties(brandingConfigurationService, locale));
-    }
-    
-    private Map<String, Object> computeBrandingConfigurationProperties(BrandingConfigurationService brandingConfigurationService, Optional<String> requestLocale) {
-        final Map<String, Object> brandingProperties = new HashMap<>(); // no concurrency control needed within single request
-        brandingConfigurationService.getBrandingConfigurationPropertiesForJspContext(requestLocale).forEach((k, v) -> {
-            brandingProperties.put(k.getPropertyName(), v);
-        });
-        return brandingProperties;
-    }
-
     @Override
     public void requestDestroyed(ServletRequestEvent sre) {
         // intentionally left blank

java/com.sap.sse.branding/src/com/sap/sse/branding/impl/BrandingConfigurationServiceImpl.java

@@ -1,29 +1,54 @@
 package com.sap.sse.branding.impl;
 
+import java.util.Arrays;
 import java.util.HashMap;
+import java.util.Iterator;
 import java.util.Map;
 import java.util.Map.Entry;
 import java.util.Optional;
+import java.util.concurrent.ConcurrentHashMap;
+import java.util.concurrent.ConcurrentMap;
+import java.util.logging.Logger;
 
 import org.json.simple.JSONObject;
 import org.osgi.framework.BundleContext;
 import org.osgi.framework.Constants;
 import org.osgi.framework.Filter;
 import org.osgi.framework.InvalidSyntaxException;
+import org.osgi.framework.ServiceReference;
 import org.osgi.util.tracker.ServiceTracker;
+import org.osgi.util.tracker.ServiceTrackerCustomizer;
 
 import com.sap.sse.branding.BrandingConfigurationService;
 import com.sap.sse.branding.shared.BrandingConfiguration;
+import com.sap.sse.common.Util;
+import com.sap.sse.common.Util.Pair;
 import com.sap.sse.util.ServiceTrackerFactory;
 
-public class BrandingConfigurationServiceImpl implements BrandingConfigurationService {
-    private ServiceTracker<BrandingConfiguration, BrandingConfiguration> brandingConfigurationTracker;
+public class BrandingConfigurationServiceImpl implements BrandingConfigurationService, ServiceTrackerCustomizer<BrandingConfiguration, BrandingConfiguration> {
+    private static final Logger logger = Logger.getLogger(BrandingConfigurationServiceImpl.class.getName());
+
+    private final ServiceTracker<BrandingConfiguration, BrandingConfiguration> brandingConfigurationTracker;
     
     private final BundleContext bundleContext;
     
+    private final ConcurrentMap<Pair<String, String>, Map<String, Object>> brandingConfigurationsByIdAndLocale;
+    
+    /**
+     * Starts out as {@code null}. Will be set by {@link #setActiveBrandingConfigurationById(String)} if the
+     * configuration by that ID is found through the {@link #brandingConfigurationTracker}. Furthermore,
+     * a {@link ServiceTrackerCustomizer} is used to update this field whenever the service currently in
+     * use is removed or modified, or a new service matching the ID is added.
+     */
+    private BrandingConfiguration activeBrandingConfiguration;
+    
+    private Filter filterForActiveBrandingConfigurationId;
+    
     public BrandingConfigurationServiceImpl(BundleContext bundleContext) {
         super();
         this.bundleContext = bundleContext;
+        brandingConfigurationTracker = ServiceTrackerFactory.createAndOpen(bundleContext, BrandingConfiguration.class, this);
+        brandingConfigurationsByIdAndLocale = new ConcurrentHashMap<>();
     }
 
     @Override
@@ -33,18 +58,35 @@ public class BrandingConfigurationServiceImpl implements BrandingConfigurationSe
 
     @Override
     public BrandingConfiguration setActiveBrandingConfigurationById(String brandingConfigurationId) {
+        filterForActiveBrandingConfigurationId = createFilterForBrandingConfigurationId(brandingConfigurationId);
+        activeBrandingConfiguration = brandingConfigurationTracker.getServiceReferences() == null ? null :
+            Arrays.asList(brandingConfigurationTracker.getServiceReferences())
+                .stream()
+                .filter(ref -> filterForActiveBrandingConfigurationId.match(ref.getProperties()))
+                .findFirst()
+                .map(ref -> brandingConfigurationTracker.getService(ref))
+                .orElse(null);
+        if (activeBrandingConfiguration == null) {
+            logger.warning("Couldn't find a branding configuration with ID " + brandingConfigurationId +
+                    " in the OSGi service registry. Branding is effectively deactivated.");
+        } else {
+            logger.info("Found active branding configuration: " + activeBrandingConfiguration.getId()+
+                    " with object ID "+System.identityHashCode(activeBrandingConfiguration));
+        }
+        return activeBrandingConfiguration;
+    }
+
+    private Filter createFilterForBrandingConfigurationId(String brandingConfigurationId) {
         try {
-            Filter filter = bundleContext.createFilter(
+            return bundleContext.createFilter(
                     String.format("(&(%s=%s)(%s=%s))",
                             BrandingConfigurationService.BRANDING_ID_PROPERTY_NAME, ""+brandingConfigurationId,
                             Constants.OBJECTCLASS, BrandingConfiguration.class.getName()));
-            brandingConfigurationTracker = ServiceTrackerFactory.createAndOpen(bundleContext, filter);
-            return brandingConfigurationTracker.getService();
         } catch (InvalidSyntaxException e) {
             throw new RuntimeException("Internal error: Invalid filter syntax for BrandingConfigurationService", e);
         }
     }
-
+    
     @Override
     public BrandingConfiguration getActiveBrandingConfiguration() {
         return brandingConfigurationTracker == null ? null : brandingConfigurationTracker.getService();
@@ -52,7 +94,7 @@ public class BrandingConfigurationServiceImpl implements BrandingConfigurationSe
 
 
     @Override
-    public Map<BrandingConfigurationProperty, Object> getBrandingConfigurationPropertiesForJspContext(Optional<String> locale) {
+    public Map<BrandingConfigurationProperty, Object> getBrandingConfigurationProperties(Optional<String> locale) {
         final BrandingConfiguration brandingConfiguration = getActiveBrandingConfiguration();
         final Map<BrandingConfigurationProperty, Object> map = new HashMap<>();
         final String title;
@@ -64,7 +106,6 @@ public class BrandingConfigurationServiceImpl implements BrandingConfigurationSe
             title = "";
             whitelabeled = "-whitelabeled";
         }
-        // TODO bug6060: figure out how to deal with i18n and the locale parameter
         map.put(BrandingConfigurationProperty.BRAND_TITLE_WITH_TRAILING_SPACE_JSP_PROPERTY_NAME, title);
         map.put(BrandingConfigurationProperty.DEBRANDING_ACTIVE_JSP_PROPERTY_NAME, !isBrandingActive());
         map.put(BrandingConfigurationProperty.BRANDING_ACTIVE_JSP_PROPERTY_NAME, isBrandingActive());
@@ -73,6 +114,21 @@ public class BrandingConfigurationServiceImpl implements BrandingConfigurationSe
         return map;
     }
 
+    @Override
+    public Map<String, Object> getBrandingConfigurationPropertiesForJspContext(Optional<String> locale) {
+        return brandingConfigurationsByIdAndLocale.computeIfAbsent(
+                new Pair<>(locale.orElse(null), isBrandingActive() ? getActiveBrandingConfiguration().getId() : null),
+                key -> computeBrandingConfigurationProperties(locale));
+    }
+
+    private Map<String, Object> computeBrandingConfigurationProperties(Optional<String> requestLocale) {
+        final Map<String, Object> brandingProperties = new HashMap<>(); // no concurrency control needed within single request
+        getBrandingConfigurationProperties(requestLocale).forEach((k, v) -> {
+            brandingProperties.put(k.getPropertyName(), v);
+        });
+        return brandingProperties;
+    }
+
     private Object generateScriptForClientConfigurationContext(Map<BrandingConfigurationProperty, Object> map) {
         final StringBuilder scriptBuilder = new StringBuilder();
         scriptBuilder.append("document.clientConfigurationContext=");
@@ -84,4 +140,56 @@ public class BrandingConfigurationServiceImpl implements BrandingConfigurationSe
         scriptBuilder.append(";");
         return scriptBuilder.toString();
     }
+
+    @Override
+    public BrandingConfiguration addingService(ServiceReference<BrandingConfiguration> reference) {
+        final BrandingConfiguration service = evictCachedPropertiesForBrandingServiceReference(reference);
+        logger.info("Adding branding configuration service with ID: " + reference.getProperty(BrandingConfigurationService.BRANDING_ID_PROPERTY_NAME) +
+                " and object ID " + System.identityHashCode(service));
+        if (service != null && filterForActiveBrandingConfigurationId.match(reference)) {
+            logger.info("Added branding configuration service with ID " + reference.getProperty(BrandingConfigurationService.BRANDING_ID_PROPERTY_NAME) +
+                    " is selected as the active one.");
+            activeBrandingConfiguration = service;
+        }
+        return service;
+    }
+
+    private BrandingConfiguration evictCachedPropertiesForBrandingServiceReference(
+            ServiceReference<BrandingConfiguration> reference) {
+        final String brandingId = (String) reference.getProperty(BrandingConfigurationService.BRANDING_ID_PROPERTY_NAME);
+        final BrandingConfiguration service = bundleContext.getService(reference);
+        for (final Iterator<Pair<String, String>> i=brandingConfigurationsByIdAndLocale.keySet().iterator(); i.hasNext(); ) {
+            final Pair<String, String> cachedProperties = i.next();
+            if (Util.equalsWithNull(cachedProperties.getB(), brandingId)) {
+                logger.info("Removing cached branding properties from service with ID: " + brandingId + " and object ID " + System.identityHashCode(service));
+                // remove the cached properties for this ID, so that they will be recomputed
+                i.remove();
+            }
+        }
+        return service;
+    }
+
+    @Override
+    public void modifiedService(ServiceReference<BrandingConfiguration> reference, BrandingConfiguration service) {
+        evictCachedPropertiesForBrandingServiceReference(reference);
+        logger.info("Modified branding configuration service with ID: " + reference.getProperty(BrandingConfigurationService.BRANDING_ID_PROPERTY_NAME) +
+                " and object ID " + System.identityHashCode(service));
+        if (service != null && filterForActiveBrandingConfigurationId.match(reference)) {
+            logger.info("Modified branding configuration service with ID " + reference.getProperty(BrandingConfigurationService.BRANDING_ID_PROPERTY_NAME) +
+                    ", updating active branding configuration.");
+            activeBrandingConfiguration = service;
+        }
+    }
+
+    @Override
+    public void removedService(ServiceReference<BrandingConfiguration> reference, BrandingConfiguration service) {
+        evictCachedPropertiesForBrandingServiceReference(reference);
+        logger.info("Removed branding configuration service with ID: " + reference.getProperty(BrandingConfigurationService.BRANDING_ID_PROPERTY_NAME) +
+                " and object ID " + System.identityHashCode(service));
+        if (service == activeBrandingConfiguration) {
+            logger.info("The active branding configuration service with ID " + reference.getProperty(BrandingConfigurationService.BRANDING_ID_PROPERTY_NAME) +
+                    " was removed, setting active branding configuration to null.");
+            activeBrandingConfiguration = null;
+        }
+    }
 }

java/com.sap.sse.gwt/META-INF/MANIFEST.MF

@@ -16,6 +16,7 @@ Require-Bundle: com.google.gwt.user;bundle-version="2.10.0";resolution:=optional
 Bundle-ActivationPolicy: lazy
 Web-ContextPath: /gwt-base
 Import-Package: com.sap.sse.branding.shared,
+ com.sap.sse.security,
  com.sun.jersey.spi.container.servlet;version="[1.17.0,2.0.0)",
  javax.servlet;version="3.1.0",
  javax.servlet.descriptor;version="3.1.0",

java/com.sap.sse.gwt/src/com/sap/sse/gwt/shared/ClientConfiguration.java

@@ -20,7 +20,7 @@ import com.sap.sse.gwt.client.context.impl.ClientConfigurationContextDataFactory
  *      document.clientConfigurationContext={"brandingActive":true,"brandTitle":"SAP ","debrandingActive":false,"whitelabeled":""};
  * </pre>
  * That can be accessed from here using the {@link ClientConfigurationContextDataJSO}. Responsible for the properties listed in the
- * object is {@link BrandingConfigurationService#getBrandingConfigurationPropertiesForJspContext(Optional)} and its
+ * object is {@link BrandingConfigurationService#getBrandingConfigurationProperties(Optional)} and its
  * {@link BrandingConfigurationService#getActiveBrandingConfiguration() active branding configuration}, or none if the solution
  * is running without any branding.<p>
  *