Created new ServiceLoaders class to encapsulate ClassLoader workarounds

Author: chkal

core/src/main/java/org/mvcspec/ozark/bootstrap/OzarkInitializer.java

@@ -17,12 +17,12 @@
 
 import org.mvcspec.ozark.core.ViewResponseFilter;
 import org.mvcspec.ozark.servlet.OzarkContainerInitializer;
+import org.mvcspec.ozark.util.ServiceLoaders;
 
 import javax.servlet.ServletContext;
 import javax.ws.rs.core.Configuration;
 import javax.ws.rs.core.FeatureContext;
 import java.util.Objects;
-import java.util.ServiceLoader;
 import java.util.Set;
 import java.util.logging.Level;
 import java.util.logging.Logger;
@@ -56,19 +56,7 @@ public static void initialize(FeatureContext context, ServletContext servletCont
 
             log.info("Initializing Ozark...");
 
-            // classloader to use for ServiceLoader lookups
-            ClassLoader classLoader = Thread.currentThread().getContextClassLoader();
-
-            /*
-             * Special workaround for TomEE . The context classloader is an instance of CxfContainerClassLoader
-             * and NOT the TomEEWebappClassLoader, which seems to break when redeploying apps into a running
-             * container for some reason.
-             */
-            if (classLoader.getClass().getName().contains("CxfContainerClassLoader")) {
-                classLoader = ConfigProvider.class.getClassLoader();
-            }
-
-            for (ConfigProvider provider : ServiceLoader.load(ConfigProvider.class, classLoader)) {
+            for (ConfigProvider provider : ServiceLoaders.list(ConfigProvider.class)) {
                 log.log(Level.FINE, "Executing: {0}", provider.getClass().getName());
                 provider.configure(context);
             }

core/src/main/java/org/mvcspec/ozark/util/ServiceLoaders.java

@@ -0,0 +1,56 @@
+/*
+ * Copyright © 2017 Ivar Grimstad ([email protected])
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.mvcspec.ozark.util;
+
+import org.mvcspec.ozark.bootstrap.ConfigProvider;
+
+import java.util.List;
+import java.util.ServiceLoader;
+import java.util.stream.Collectors;
+import java.util.stream.StreamSupport;
+
+/**
+ * Utility code for the {@link ServiceLoader} class.
+ *
+ * @author Christian Kaltepoth
+ */
+public class ServiceLoaders {
+
+    private ServiceLoaders() {
+        // only static methods
+    }
+
+    public static <T> List<T> list(Class<T> type) {
+
+        // classloader to use for ServiceLoader lookups
+        ClassLoader classLoader = Thread.currentThread().getContextClassLoader();
+
+        /*
+         * Special workaround for TomEE . The context classloader is an instance of CxfContainerClassLoader
+         * and NOT the TomEEWebappClassLoader, which seems to break when redeploying apps into a running
+         * container for some reason.
+         */
+        if (classLoader.getClass().getName().contains("CxfContainerClassLoader")) {
+            classLoader = ConfigProvider.class.getClassLoader();
+        }
+
+        // return the SPI implementations as a list
+        return StreamSupport.stream(ServiceLoader.load(type, classLoader).spliterator(), false)
+                .collect(Collectors.toList());
+
+    }
+
+}