Add lightweight context

README.md

@@ -31,3 +31,14 @@ Utilities to facilitate Java applications development.
 
 ``$ mvn clean verify coreutils``
 
+## Examples (pending)
+
+- Spring Boot + Undertow
+
+## TO-DO list:
+
+1. Improve documentation: this is not framework, this is not a utility library. If you need a framework, we recommend Spring (Spring Boot, Spring Data, Spring REST and Spring Cloud) as a full-featured framework. For small and medium-sized projects we recommend the Jodd micro-framework. http://jodd.org/ ...
+2. Migrate part of the naming utilities.
+3. HTTP2 client: get access to the original instance (OkHttpClient) using the clone method in the case of the manager client.
+4. Check that query parameters are proxied in opengateway.
+5. Add global shutdown hook and register tasks.

coreutils-common/pom.xml

@@ -24,10 +24,11 @@ that you distribute must include a readable copy of the "NOTICE" text file.
 <project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
 	xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
 	<modelVersion>4.0.0</modelVersion>
+	
 	<parent>
 		<groupId>es.upv.grycap.coreutils</groupId>
 		<artifactId>coreutils</artifactId>
-		<version>0.1.0</version>
+		<version>0.2.0</version>
 	</parent>
 	
 	<artifactId>coreutils-common</artifactId>

coreutils-common/src/main/java/es/upv/grycap/coreutils/common/CoreutilsContext.java

@@ -0,0 +1,230 @@
+/*
+ * Core Utils - Common Utilities.
+ * Copyright 2015-2016 GRyCAP (Universitat Politecnica de Valencia)
+ * 
+ * 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.
+ * 
+ * This product combines work with different licenses. See the "NOTICE" text
+ * file for details on the various modules and licenses.
+ * 
+ * The "NOTICE" text file is part of the distribution. Any derivative works
+ * that you distribute must include a readable copy of the "NOTICE" text file.
+ */
+
+package es.upv.grycap.coreutils.common;
+
+import static java.util.Collections.emptyMap;
+import static java.util.Objects.requireNonNull;
+import static java.util.Optional.ofNullable;
+import static java.util.concurrent.TimeUnit.MILLISECONDS;
+
+import java.util.EnumMap;
+import java.util.HashMap;
+import java.util.Map;
+import java.util.concurrent.locks.Lock;
+import java.util.concurrent.locks.ReentrantLock;
+import java.util.function.Supplier;
+
+import javax.annotation.Nullable;
+import javax.annotation.concurrent.ThreadSafe;
+
+/**
+ * Lightweight and unopinionated central class for providing configuration information to a coreutils-powered application.
+ * @author Erik Torres <etserrano@gmail.com>
+ * @since 0.2.0
+ */
+@ThreadSafe
+public enum CoreutilsContext {
+
+	COREUTILS_CONTEXT;
+
+	private static final long TIMEOUT_MILLISECS = 2000l;
+
+	private final Map<ContextKey, Map<String, Object>> registry = new EnumMap<>(ContextKey.class);
+	private final Lock mutex = new ReentrantLock();
+	private final BooleanReference register = new BooleanReference(false);
+
+	/**
+	 * Gets a client from the registry.
+	 * @param type - the expected type of client
+	 * @return An instance that matches the specified type, or <tt>null</tt> if no instance with the specified properties is 
+	 *         found in the registry.
+	 */
+	@Nullable
+	public <T> T getClient(final Class<T> type) {
+		return getClient(type, null, null);
+	}
+
+	/**
+	 * Gets a client from the registry. Callers can optionally specify a classifier.
+	 * @param type - the expected type of client
+	 * @param classifier - (optional) only clients matching the classifier will be selected 
+	 * @return An instance that matches the specified type and classifier, or <tt>null</tt> if no instance with the specified 
+	 *         properties is found in the registry.
+	 */
+	@Nullable
+	public <T> T getClient(final Class<T> type, final @Nullable String classifier) {
+		return getClient(type, classifier, null);
+	}
+
+	/**
+	 * Gets a client from the registry. In case that no instance with the specified properties is found in the registry, the
+	 * optional supplier will be used to create a new instance that will be registered. 
+	 * @param type - the expected type of client
+	 * @param supplier - (optional) client factory
+	 * @return An instance that matches the specified type, or a new instance created with the supplier if no instance with 
+	 *         the specified properties is found in the registry.
+	 */
+	@Nullable
+	public <T> T getClient(final Class<T> type, final @Nullable Supplier<T> supplier) {
+		return getClient(type, null, supplier);
+	}
+
+	/**
+	 * Gets a client from the registry. Callers can optionally specify a classifier. In case that no instance with the specified 
+	 * properties is found in the registry, the optional supplier will be used to create a new instance that will be registered.
+	 * @param type - the expected type of client
+	 * @param classifier - (optional) only clients matching the classifier will be selected
+	 * @param supplier - (optional) client factory
+	 * @return An instance that matches the specified type and classifier, or a new instance created with the supplier if no 
+	 *         instance with the specified properties is found in the registry.
+	 */
+	@Nullable
+	public <T> T getClient(final Class<T> type, final @Nullable String classifier, final @Nullable Supplier<T> supplier) {
+		return get(ContextKey.CLIENTS, type, classifier, supplier);
+	}
+
+	/**
+	 * Registers a new shutdown listener for the specified type.
+	 * @param listener - the listener that will be registered
+	 * @param type - the type of the shutdown listener
+	 */
+	public <T extends ShutdownListener> void addShutdownListener(final T listener, final Class<T> type) {
+		addShutdownListener(listener, type, null);
+	}
+
+	/**
+	 * Registers a new shutdown listener for the specified type with an optional classifier.
+	 * @param listener - the listener that will be registered
+	 * @param type - the type of the shutdown listener
+	 * @param classifier - (optional) add this classifier to the registry
+	 */
+	public <T extends ShutdownListener> void addShutdownListener(final T listener, final Class<T> type, final @Nullable String classifier) {
+		requireNonNull(listener, "A non-null listener expected");
+		final ShutdownListener listener2 = get(ContextKey.SHUTDOWN_LISTENERS, type, classifier, () -> listener);
+		if (listener != listener2) {
+			throw new IllegalStateException("A previous shutdown listener was registered, try with a different classifier");
+		}
+	}
+
+	/**
+	 * Unregister a shutdown listener.
+	 * @param type - the type of the shutdown listener	
+	 */
+	public <T extends ShutdownListener> void removeShutdownListener(final Class<T> type) {
+		removeShutdownListener(type, null);
+	}
+
+	/**
+	 * Unregister a shutdown listener.
+	 * @param type - the type of the shutdown listener
+	 * @param classifier - (optional) classifier
+	 */
+	public <T extends ShutdownListener> void removeShutdownListener(final Class<T> type, final @Nullable String classifier) {
+		remove(ContextKey.SHUTDOWN_LISTENERS, type, classifier);
+	}
+
+	@Nullable
+	@SuppressWarnings("unchecked")
+	private <T> T get(final ContextKey key, final Class<T> type, final @Nullable String classifier, final @Nullable Supplier<T> supplier) {
+		requireNonNull(type, "A non-null type expected");
+		try {
+			mutex.tryLock(TIMEOUT_MILLISECS, MILLISECONDS);
+			try {
+				// lazy initialization of the registry
+				register.set(false);
+				final Map<String, Object> map = ofNullable(registry.get(key)).orElseGet(() -> {
+					register.set(true);
+					return new HashMap<>(1);
+				});
+				if (register.get()) registry.put(key, map);
+				// get or create the instance
+				register.set(false);
+				final String instanceKey = instanceKey(type, classifier);
+				final T instance = (T)ofNullable(map.get(instanceKey)).orElseGet(() -> {
+					final T tmp = ofNullable(supplier).orElse(() -> null).get();
+					if (tmp != null) register.set(true);
+					return tmp;
+				});
+				if (register.get()) map.put(instanceKey, instance);
+				return instance;
+			} finally {
+				mutex.unlock();
+			}
+		} catch (InterruptedException e) {
+			throw new IllegalStateException("The operation was interrupted");
+		}
+	}
+
+	private <T> void remove(final ContextKey key, final Class<T> type, final @Nullable String classifier) {
+		requireNonNull(type, "A non-null type expected");
+		try {
+			mutex.tryLock(TIMEOUT_MILLISECS, MILLISECONDS);
+			try {
+				ofNullable(registry.get(key)).orElse(emptyMap()).remove(instanceKey(type, classifier));
+			} finally {
+				mutex.unlock();
+			}
+		} catch (InterruptedException e) {
+			throw new IllegalStateException("The operation was interrupted");
+		}
+	}
+
+	private <T> String instanceKey(final Class<T> type, final @Nullable String classifier) {
+		return String.format("%s@%s", type.getCanonicalName(), ofNullable(classifier).orElse(""));
+	}
+
+	/**
+	 * The different types of objects that can be stored within this context.
+	 * @author Erik Torres <etserrano@gmail.com>
+	 * @since 0.2.0
+	 */
+	private enum ContextKey {
+		CLIENTS,
+		SHUTDOWN_LISTENERS
+	}
+
+	/**
+	 * Provides a reference to a boolean variable but without the synchronization cost of a atomic type.
+	 * @author Erik Torres <etserrano@gmail.com>
+	 * @since 0.2.0
+	 */
+	private static class BooleanReference {
+
+		private boolean value = false;
+
+		public BooleanReference(final boolean value) {		
+			this.value = value;
+		}
+
+		public boolean get() {
+			return value;
+		}
+
+		public void set(final boolean value) {
+			this.value = value;
+		}
+
+	}
+
+}

coreutils-common/src/main/java/es/upv/grycap/coreutils/common/ShutdownHook.java

@@ -0,0 +1,111 @@
+/*
+ * Core Utils - Common Utilities.
+ * Copyright 2015-2016 GRyCAP (Universitat Politecnica de Valencia)
+ * 
+ * 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.
+ * 
+ * This product combines work with different licenses. See the "NOTICE" text
+ * file for details on the various modules and licenses.
+ * 
+ * The "NOTICE" text file is part of the distribution. Any derivative works
+ * that you distribute must include a readable copy of the "NOTICE" text file.
+ */
+
+package es.upv.grycap.coreutils.common;
+
+import static java.util.Collections.synchronizedMap;
+import static java.util.Objects.requireNonNull;
+import static java.util.concurrent.Executors.newSingleThreadExecutor;
+import static java.util.concurrent.TimeUnit.SECONDS;
+
+import java.util.LinkedHashMap;
+import java.util.Map;
+import java.util.concurrent.ExecutorService;
+
+import javax.annotation.concurrent.ThreadSafe;
+
+/**
+ * Executes a shutdown sequence when the JVM shutdowns, calling the {@link ShutdownListener#stop()} method of the registered listeners 
+ * and waiting until they finish or a timeout expires.
+ * @author Erik Torres <etserrano@gmail.com>
+ * @since 0.2.0
+ */
+@ThreadSafe
+public class ShutdownHook {	
+
+	private final int TIMEOUT_SECS = 8;
+	private final Thread hook;
+
+	/**
+	 * Thread-safe map that preserves the insertion order of the entries.
+	 */
+	private final Map<String, ShutdownListener> listeners = synchronizedMap(new LinkedHashMap<String, ShutdownListener>());
+
+	/**
+	 * Creates an instance of this class and registers it with the JVM.
+	 */
+	public ShutdownHook() {
+		hook = new Thread() {
+			@Override
+			public void run() {
+				final ExecutorService executor = newSingleThreadExecutor();				
+				for (final Map.Entry<String, ShutdownListener> entry : listeners.entrySet()) {
+					final ShutdownListener listener = entry.getValue();
+					if (listener != null) {
+						executor.execute(new Runnable() {							
+							@Override
+							public void run() {
+								try {
+									listener.stop();
+								} catch (Exception ignore) { }
+							}
+						});						
+					}					
+				}
+				try {
+					if (!executor.awaitTermination(TIMEOUT_SECS, SECONDS)) {
+						executor.shutdown();
+					}
+				} catch (Exception e) {
+					// force shutdown if current thread also interrupted, preserving interrupt status
+					executor.shutdown();
+					if (e instanceof InterruptedException) {
+						Thread.currentThread().interrupt();
+					}
+				}
+			}
+		};
+		Runtime.getRuntime().addShutdownHook(hook);
+	}
+
+	/**
+	 * Registers a listener for shutdown.
+	 * @param listener - the listener that will be added to the shutdown sequence
+	 */
+	public void register(final ShutdownListener listener) {
+		requireNonNull(listener, "A non-null listener expected");
+		final String name = listener.getClass().getCanonicalName();
+		listeners.put(name, listener);
+	}
+
+	/**
+	 * Cancels the execution of the shutdown sequence specified in this class.
+	 */
+	public void cancel() {
+		try {
+			Runtime.getRuntime().removeShutdownHook(hook);
+		} catch (Exception ignore) { }
+		listeners.clear();
+	}
+
+}

coreutils-common/src/main/java/es/upv/grycap/coreutils/common/ShutdownListener.java

@@ -0,0 +1,53 @@
+/*
+ * Core Utils - Common Utilities.
+ * Copyright 2015-2016 GRyCAP (Universitat Politecnica de Valencia)
+ * 
+ * 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.
+ * 
+ * This product combines work with different licenses. See the "NOTICE" text
+ * file for details on the various modules and licenses.
+ * 
+ * The "NOTICE" text file is part of the distribution. Any derivative works
+ * that you distribute must include a readable copy of the "NOTICE" text file.
+ */
+
+package es.upv.grycap.coreutils.common;
+
+import java.util.concurrent.atomic.AtomicBoolean;
+
+/**
+ * Shutdown listener.
+ * @author Erik Torres <etserrano@gmail.com>
+ * @since 0.2.0
+ */
+public abstract class ShutdownListener {
+
+	/**
+	 * Maintains the status of the instance.
+	 */
+	protected final AtomicBoolean isRunning = new AtomicBoolean(false);	
+	
+	/**
+	 * Sets the value of {@link #isRunning} to <tt>true</tt>.
+	 */
+	public void init() {
+		isRunning.compareAndSet(false, true);
+	}
+	
+	/**
+	 * Calling this method should set the value of {@link #isRunning} to <tt>false</tt>. Implementations should check that the value is
+	 * <tt>true</tt> before entering the stop sequence.
+	 */
+	public abstract void stop();
+	
+}

coreutils-common/src/test/java/es/upv/grycap/coreutils/common/test/CoreutilsContextTest.java

@@ -0,0 +1,141 @@
+/*
+ * Core Utils - Common Utilities.
+ * Copyright 2015-2016 GRyCAP (Universitat Politecnica de Valencia)
+ * 
+ * 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.
+ * 
+ * This product combines work with different licenses. See the "NOTICE" text
+ * file for details on the various modules and licenses.
+ * 
+ * The "NOTICE" text file is part of the distribution. Any derivative works
+ * that you distribute must include a readable copy of the "NOTICE" text file.
+ */
+
+package es.upv.grycap.coreutils.common.test;
+
+import static es.upv.grycap.coreutils.common.CoreutilsContext.COREUTILS_CONTEXT;
+import static org.hamcrest.CoreMatchers.allOf;
+import static org.hamcrest.CoreMatchers.equalTo;
+import static org.hamcrest.CoreMatchers.not;
+import static org.hamcrest.CoreMatchers.notNullValue;
+import static org.hamcrest.CoreMatchers.nullValue;
+import static org.hamcrest.MatcherAssert.assertThat;
+
+import java.util.Objects;
+import java.util.Random;
+
+import org.junit.AfterClass;
+import org.junit.BeforeClass;
+import org.junit.Rule;
+import org.junit.Test;
+import org.junit.experimental.categories.Category;
+import org.junit.rules.TestRule;
+
+import es.upv.grycap.coreutils.common.ShutdownListener;
+import es.upv.grycap.coreutils.test.category.FunctionalTests;
+import es.upv.grycap.coreutils.test.rules.TestPrinter;
+import es.upv.grycap.coreutils.test.rules.TestWatcher2;
+
+/**
+ * Tests the context.
+ * @author Erik Torres <etserrano@gmail.com>
+ * @since 0.2.0
+ */
+@Category(FunctionalTests.class)
+public class CoreutilsContextTest {
+
+	@Rule
+	public TestPrinter pw = new TestPrinter(true);
+
+	@Rule
+	public TestRule watchman = new TestWatcher2(pw);
+	
+	@BeforeClass
+	public static void setup() {
+		COREUTILS_CONTEXT.addShutdownListener(new FakeShutdownListener(), FakeShutdownListener.class, "duplicate");
+	}
+	
+	@AfterClass
+	public static void cleanup() {
+		COREUTILS_CONTEXT.removeShutdownListener(FakeShutdownListener.class, "duplicate");
+	}
+
+	@Test
+	public void testRegistry() throws Exception {		
+		assertThat("Client is null", COREUTILS_CONTEXT.getClient(FakeClient.class), nullValue());
+
+		final FakeClient client = COREUTILS_CONTEXT.getClient(FakeClient.class, FakeClient::new);
+		assertThat("Client is not null", client, notNullValue());
+
+		FakeClient client2 = COREUTILS_CONTEXT.getClient(FakeClient.class, FakeClient::new);
+		assertThat("Client coincides with expected", client2, allOf(notNullValue(), equalTo(client)));
+
+		client2 = COREUTILS_CONTEXT.getClient(FakeClient.class, "classifier", FakeClient::new);
+		assertThat("Client coincides with expected", client2, allOf(notNullValue(), not(equalTo(client))));
+	}
+	
+	@Test
+	public void testShutdownhook() throws Exception {
+		COREUTILS_CONTEXT.addShutdownListener(new FakeShutdownListener(), FakeShutdownListener.class);		
+		COREUTILS_CONTEXT.removeShutdownListener(FakeShutdownListener.class);
+	}
+	
+	@Test(expected=IllegalStateException.class) 
+	public void testDuplicateShutdownhook() {
+		COREUTILS_CONTEXT.addShutdownListener(new FakeShutdownListener(), FakeShutdownListener.class, "duplicate");
+	}
+
+	/**
+	 * Client mock-up.
+	 * @author Erik Torres <etserrano@gmail.com>
+	 * @since 0.2.0
+	 */
+	public static class FakeClient {
+
+		private final int id = new Random().nextInt();
+
+		public int getId() {
+			return id;
+		}
+
+		@Override
+		public boolean equals(final Object obj) {
+			if (obj == null || !(obj instanceof FakeClient)) {
+				return false;
+			}
+			final FakeClient other = FakeClient.class.cast(obj);
+			return Objects.equals(id, other.id);
+		}
+
+		@Override
+		public int hashCode() {
+			return Objects.hash(id);
+		}
+
+	}
+	
+	/**
+	 * Shutdown listener mock-up.
+	 * @author Erik Torres <etserrano@gmail.com>
+	 * @since 0.2.0
+	 */
+	public static class FakeShutdownListener extends ShutdownListener {
+
+		@Override
+		public void stop() {
+			if (isRunning.get());
+		}
+		
+	}
+
+}

coreutils-fiber/pom.xml

@@ -28,7 +28,7 @@ that you distribute must include a readable copy of the "NOTICE" text file.
 	<parent>
 		<groupId>es.upv.grycap.coreutils</groupId>
 		<artifactId>coreutils</artifactId>
-		<version>0.1.0</version>
+		<version>0.2.0</version>
 	</parent>
 	
 	<artifactId>coreutils-fiber</artifactId>
@@ -138,7 +138,7 @@ that you distribute must include a readable copy of the "NOTICE" text file.
 					<version>${m2e.lifecycle-mapping.version}</version>
 					<configuration>
 						<lifecycleMappingMetadata>
-							<pluginExecutions>								
+							<pluginExecutions>
 								<pluginExecution>
 									<pluginExecutionFilter>
 										<groupId>org.apache.maven.plugins</groupId>

coreutils-fiber/src/main/java/es/upv/grycap/coreutils/fiber/http/Http2Client.java

@@ -24,30 +24,19 @@
 package es.upv.grycap.coreutils.fiber.http;
 
 import static com.google.common.collect.Lists.newArrayList;
-import static java.nio.file.Files.createTempDirectory;
-import static java.nio.file.attribute.PosixFilePermissions.asFileAttribute;
-import static java.nio.file.attribute.PosixFilePermissions.fromString;
 import static java.util.Collections.emptyList;
 import static java.util.Objects.requireNonNull;
 import static java.util.Optional.ofNullable;
 import static org.apache.commons.lang3.StringUtils.trimToNull;
-import static org.slf4j.LoggerFactory.getLogger;
 
-import java.io.File;
 import java.io.IOException;
 import java.util.List;
 import java.util.Objects;
 import java.util.concurrent.TimeUnit;
-import java.util.concurrent.locks.Lock;
-import java.util.concurrent.locks.ReentrantLock;
 import java.util.function.Supplier;
 
 import javax.annotation.Nullable;
 
-import org.apache.commons.io.FileUtils;
-import org.slf4j.Logger;
-
-import com.squareup.okhttp.Cache;
 import com.squareup.okhttp.CacheControl;
 import com.squareup.okhttp.Callback;
 import com.squareup.okhttp.MediaType;
@@ -55,7 +44,6 @@ import com.squareup.okhttp.OkHttpClient;
 import com.squareup.okhttp.Request;
 import com.squareup.okhttp.RequestBody;
 
-import co.paralleluniverse.fibers.okhttp.FiberOkHttpClient;
 import okio.BufferedSink;
 
 /**
@@ -63,49 +51,16 @@ import okio.BufferedSink;
  * @author Erik Torres <etserrano@gmail.com>
  * @since 0.1.0
  */
-public class Http2Client {
+public final class Http2Client {
 
-	private static final Logger LOGGER = getLogger(Http2Client.class);
-
-	private static final int CACHE_SIZE_MIB = 32 * 1024 * 1024; // 32 MiB
-
-	private static OkHttpClient __client = null;
-
-	private Lock mutex = new ReentrantLock();
-
-	public static Http2Client getHttp2Client() {
-		return new Http2Client();
-	}
+	private final OkHttpClient client;
 
 	/**
-	 * Creates a {@link OkHttpClient} instance and configures it with a cache. The same instance is used across the application to
-	 * benefit from a common cache storage and to prevent cache corruption. The cache directory is created private to the user who
-	 * runs the application and its content is deleted when the JVM starts its shutting down sequence.
-	 * @return A {@link OkHttpClient} instance that can be used everywhere in the application.
+	 * Access to this constructor is restricted to the classes in the same package. A factory method should be used to 
+	 * create new instances of this class.
 	 */
-	private OkHttpClient client() {
-		mutex.lock();
-		try {
-			if (__client == null) {
-				__client = new FiberOkHttpClient();
-				try {
-					final File cacheDir = createTempDirectory("coreutils-okhttp-cache-", asFileAttribute(fromString("rwx------"))).toFile();
-					Runtime.getRuntime().addShutdownHook(new Thread() {
-						@Override
-						public void run() {
-							FileUtils.deleteQuietly(cacheDir);
-						}
-					});
-					final Cache cache = new Cache(cacheDir, CACHE_SIZE_MIB);					
-					__client.setCache(cache);
-				} catch (IOException e) {
-					LOGGER.error("Failed to create directory cache", e);
-				}
-			}
-			return __client;
-		} finally {
-			mutex.unlock();
-		}
+	Http2Client(final OkHttpClient client) {
+		this.client = requireNonNull(client, "A valid HTTP2 client expected");
 	}
 
 	/**
@@ -146,7 +101,7 @@ public class Http2Client {
 		final Request.Builder requestBuilder = new Request.Builder().cacheControl(cacheControlBuilder.build()).url(url2);
 		ofNullable(acceptableMediaTypes).orElse(emptyList()).stream().filter(Objects::nonNull).forEach(type -> requestBuilder.addHeader("Accept", type));
 		// submit request
-		client().newCall(requestBuilder.build()).enqueue(callback);
+		client.newCall(requestBuilder.build()).enqueue(callback);
 	}
 
 	/**
@@ -185,7 +140,7 @@ public class Http2Client {
 			}
 		}).build();
 		// submit request
-		client().newCall(request).enqueue(callback);
+		client.newCall(request).enqueue(callback);
 	}
 
 	/**
@@ -224,7 +179,7 @@ public class Http2Client {
 			}
 		}).build();
 		// submit request
-		client().newCall(request).enqueue(callback);
+		client.newCall(request).enqueue(callback);
 	}
 
 	/**
@@ -238,7 +193,7 @@ public class Http2Client {
 		// prepare request
 		final Request request = new Request.Builder().url(url2).delete().build();
 		// submit request
-		client().newCall(request).enqueue(callback);
+		client.newCall(request).enqueue(callback);
 	}
 
 }

coreutils-fiber/src/main/java/es/upv/grycap/coreutils/fiber/http/Http2Clients.java

@@ -0,0 +1,116 @@
+/*
+ * Core Utils - Fiber-enabled clients.
+ * Copyright 2015-2016 GRyCAP (Universitat Politecnica de Valencia)
+ * 
+ * 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.
+ * 
+ * This product combines work with different licenses. See the "NOTICE" text
+ * file for details on the various modules and licenses.
+ * 
+ * The "NOTICE" text file is part of the distribution. Any derivative works
+ * that you distribute must include a readable copy of the "NOTICE" text file.
+ */
+
+package es.upv.grycap.coreutils.fiber.http;
+
+import static es.upv.grycap.coreutils.common.CoreutilsContext.COREUTILS_CONTEXT;
+import static java.nio.file.Files.createTempDirectory;
+import static java.nio.file.attribute.PosixFilePermissions.asFileAttribute;
+import static java.nio.file.attribute.PosixFilePermissions.fromString;
+import static org.apache.commons.io.FileUtils.deleteQuietly;
+import static org.slf4j.LoggerFactory.getLogger;
+
+import java.io.File;
+import java.io.IOException;
+
+import org.slf4j.Logger;
+
+import com.squareup.okhttp.Cache;
+import com.squareup.okhttp.OkHttpClient;
+
+import co.paralleluniverse.fibers.okhttp.FiberOkHttpClient;
+import es.upv.grycap.coreutils.common.ShutdownListener;
+
+/**
+ * Factory class that creates new {@link Http2Client} instances.
+ * @author Erik Torres <etserrano@gmail.com>
+ * @since 0.2.0
+ */
+public final class Http2Clients {
+
+	private static final Logger LOGGER = getLogger(Http2Clients.class);
+
+	private static final int CACHE_SIZE_MIB = 32 * 1024 * 1024; // 32 MiB
+
+	/**
+	 * Gets a HTTP2 client which is expected to integrate with other tasks managed by coreutils.
+	 * @return An HTTP2 client managed by coreutils.
+	 */
+	public static Http2Client http2Client() {
+		return new Http2Client(client());
+	}
+
+	/**
+	 * Gets a new instance of the HTTP2 client that is not managed by coreutils in any way. Use this client if your application
+	 * manages its own threads or if you use any other kind of concurrent execution outside coreutils.
+	 * @return An unmanaged instance of the HTTP2 client.
+	 */
+	public static Http2Client isolatedHttp2Client() {
+		return new Http2Client(new OkHttpClient());
+	}
+
+	/**
+	 * Creates a {@link OkHttpClient} instance and configures it with a cache. The same instance is used across the application to
+	 * benefit from a common cache storage and to prevent cache corruption. The cache directory is created private to the user who
+	 * runs the application and its content is deleted when the JVM starts its shutting down sequence.
+	 * @return A {@link OkHttpClient} instance that can be used everywhere in the application.
+	 */
+	private static OkHttpClient client() {
+		return COREUTILS_CONTEXT.getClient(OkHttpClient.class, "coreutils-fiber", () -> {
+			final OkHttpClient client = new FiberOkHttpClient();
+			try {
+				final File cacheDir = createTempDirectory("coreutils-okhttp-cache-", asFileAttribute(fromString("rwx------"))).toFile();
+				final Http2ClientShutdownListener shutdownListener = new Http2ClientShutdownListener(cacheDir);
+				COREUTILS_CONTEXT.addShutdownListener(shutdownListener, Http2ClientShutdownListener.class, "coreutils-fiber");
+				final Cache cache = new Cache(cacheDir, CACHE_SIZE_MIB);					
+				client.setCache(cache);				
+			} catch (IOException e) {
+				LOGGER.error("Failed to create directory cache", e);
+			}
+			return client;
+		});
+	}
+
+	/**
+	 * Shutdown listener to delete cache directory on application exit.
+	 * @author Erik Torres <etserrano@gmail.com>
+	 * @since 0.2.0
+	 */
+	public static class Http2ClientShutdownListener extends ShutdownListener {
+
+		private final File cacheDir;
+
+		public Http2ClientShutdownListener(final File cacheDir) {
+			this.cacheDir = cacheDir;
+		}
+
+		@Override
+		public void stop() {
+			if (isRunning.getAndSet(false)) {
+				deleteQuietly(cacheDir);
+			}
+		}
+
+	}
+
+}

coreutils-fiber/src/test/java/es/upv/grycap/coreutils/fiber/test/HighlyConcurrencyTest.java

@@ -24,7 +24,8 @@
 package es.upv.grycap.coreutils.fiber.test;
 
 import static com.google.common.collect.ImmutableList.of;
-import static es.upv.grycap.coreutils.fiber.http.Http2Client.getHttp2Client;
+import static es.upv.grycap.coreutils.fiber.http.Http2Clients.http2Client;
+import static es.upv.grycap.coreutils.fiber.http.Http2Clients.isolatedHttp2Client;
 import static es.upv.grycap.coreutils.fiber.test.mockserver.FiberExpectationInitializer.MOCK_SERVER_BASE_URL;
 import static org.hamcrest.CoreMatchers.allOf;
 import static org.hamcrest.CoreMatchers.equalTo;
@@ -64,11 +65,20 @@ public class HighlyConcurrencyTest {
 	public TestRule watchman = new TestWatcher2(pw);
 
 	@Test
-	public void test() throws Exception {
-		// create the client
-		final Http2Client client = getHttp2Client();
-		assertThat("HTTP+SPDY client was created", client, notNullValue());
+	public void testManagedClient() throws Exception {
+		final Http2Client client = http2Client();
+		assertThat("HTTP+SPDY managed client was created", client, notNullValue());
+		runTest(client);
+	}
 
+	@Test
+	public void testIsolatedClient() throws Exception {
+		final Http2Client client = isolatedHttp2Client();
+		assertThat("HTTP+SPDY isolated client was created", client, notNullValue());
+		runTest(client);		
+	}
+
+	private void runTest(final Http2Client client) throws Exception {
 		// prepare the test
 		final Waiter waiter = new Waiter();
 		for (int i = 0; i < 100; i++) {
@@ -88,5 +98,5 @@ public class HighlyConcurrencyTest {
 			});
 		}
 		waiter.await(30l, TimeUnit.SECONDS, 100);
-	}	
+	}
 }

coreutils-fiber/src/test/java/es/upv/grycap/coreutils/fiber/test/Http2ClientTest.java

@@ -25,7 +25,7 @@ package es.upv.grycap.coreutils.fiber.test;
 
 import static com.google.common.collect.ImmutableList.of;
 import static com.google.common.collect.Lists.newArrayList;
-import static es.upv.grycap.coreutils.fiber.http.Http2Client.getHttp2Client;
+import static es.upv.grycap.coreutils.fiber.http.Http2Clients.http2Client;
 import static es.upv.grycap.coreutils.fiber.test.mockserver.FiberExpectationInitializer.MOCK_SERVER_BASE_URL;
 import static es.upv.grycap.coreutils.fiber.test.mockserver.ObjectResponseValidator.isValidJson;
 import static es.upv.grycap.coreutils.fiber.test.mockserver.ObjectResponseValidator.isValidXml;
@@ -115,7 +115,7 @@ public class Http2ClientTest {
 	@Test
 	public void test() throws Exception {
 		// create the client
-		final Http2Client client = getHttp2Client();
+		final Http2Client client = http2Client();
 		assertThat("HTTP+SPDY client was created", client, notNullValue());
 
 		// prepare the test

coreutils-logging/pom.xml

@@ -24,10 +24,11 @@ that you distribute must include a readable copy of the "NOTICE" text file.
 <project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
 	xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
 	<modelVersion>4.0.0</modelVersion>
+	
 	<parent>
 		<groupId>es.upv.grycap.coreutils</groupId>
 		<artifactId>coreutils</artifactId>
-		<version>0.1.0</version>
+		<version>0.2.0</version>
 	</parent>
 	
 	<artifactId>coreutils-logging</artifactId>

coreutils-test/pom.xml

@@ -28,7 +28,7 @@ that you distribute must include a readable copy of the "NOTICE" text file.
 	<parent>
 		<groupId>es.upv.grycap.coreutils</groupId>
 		<artifactId>coreutils</artifactId>
-		<version>0.1.0</version>
+		<version>0.2.0</version>
 	</parent>
 	
 	<artifactId>coreutils-test</artifactId>

coreutils-test/src/main/java/es/upv/grycap/coreutils/test/category/CodeBenchmarks.java

@@ -0,0 +1,31 @@
+/*
+ * Core Utils - Testing utilities.
+ * Copyright 2015-2016 GRyCAP (Universitat Politecnica de Valencia)
+ * 
+ * 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.
+ * 
+ * This product combines work with different licenses. See the "NOTICE" text
+ * file for details on the various modules and licenses.
+ * 
+ * The "NOTICE" text file is part of the distribution. Any derivative works
+ * that you distribute must include a readable copy of the "NOTICE" text file.
+ */
+
+package es.upv.grycap.coreutils.test.category;
+
+/**
+ * Categorize tests that are intended to evaluate the performance of the application code.
+ * @author Erik Torres <etserrano@gmail.com>
+ * @since 0.1.0
+ */
+public class CodeBenchmarks { }

coreutils-test/src/main/java/es/upv/grycap/coreutils/test/category/IntegrationTests.java

@@ -24,7 +24,7 @@
 package es.upv.grycap.coreutils.test.category;
 
 /**
- * Categorize unit tests that belongs to the integration testing group.
+ * Categorize tests that belongs to the integration testing group.
  * @author Erik Torres <etserrano@gmail.com>
  * @since 0.1.0
  */

pom.xml

@@ -25,9 +25,15 @@ that you distribute must include a readable copy of the "NOTICE" text file.
 	xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
 	<modelVersion>4.0.0</modelVersion>
 	
+	<parent>
+		<groupId>org.sonatype.oss</groupId>
+		<artifactId>oss-parent</artifactId>
+		<version>9</version>
+	</parent>
+	
 	<groupId>es.upv.grycap.coreutils</groupId>
 	<artifactId>coreutils</artifactId>
-	<version>0.1.0</version>
+	<version>0.2.0</version>
 	<packaging>pom</packaging>
 	
 	<name>Core utils project</name>
@@ -72,9 +78,9 @@ that you distribute must include a readable copy of the "NOTICE" text file.
 		<project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
 		
 		<!-- Convenience properties to set library versions -->
-		<ch.qos.logback.version>1.1.3</ch.qos.logback.version>
-		<junit.version>4.12</junit.version> <!-- affects Hamcrest version -->		
+		<ch.qos.logback.version>1.1.3</ch.qos.logback.version>		
 		<es.upv.grycap.coreutils.version>${project.version}</es.upv.grycap.coreutils.version>
+		<junit.version>4.12</junit.version> <!-- affects Hamcrest version -->
 		<org.hamcrest.version>1.3</org.hamcrest.version> <!-- affected by JUnit version -->
 		<org.mock-server.version>3.10.2</org.mock-server.version>
 		<org.slf4j.version>1.7.13</org.slf4j.version>
@@ -122,7 +128,7 @@ that you distribute must include a readable copy of the "NOTICE" text file.
 				<groupId>com.typesafe</groupId>
 				<artifactId>config</artifactId>
 				<version>1.3.0</version>
-			</dependency>			
+			</dependency>
 			
 			<!-- Integrates with Quasar fibers via the Comsat APIs -->
 			<dependency>
@@ -206,6 +212,31 @@ that you distribute must include a readable copy of the "NOTICE" text file.
 	<build>
 		<pluginManagement>
 			<plugins>
+				<!-- Prevent Eclipse from executing unnecessary plugins during development -->
+				<plugin>
+					<groupId>org.eclipse.m2e</groupId>
+					<artifactId>lifecycle-mapping</artifactId>
+					<version>${m2e.lifecycle-mapping.version}</version>
+					<configuration>
+						<lifecycleMappingMetadata>
+							<pluginExecutions>
+								<pluginExecution>
+									<pluginExecutionFilter>
+										<groupId>org.apache.maven.plugins</groupId>
+										<artifactId>maven-enforcer-plugin</artifactId>
+										<versionRange>[1.0.0,)</versionRange>
+										<goals>
+											<goal>enforce</goal>
+										</goals>
+									</pluginExecutionFilter>
+									<action>
+										<ignore />
+									</action>
+								</pluginExecution>
+							</pluginExecutions>
+						</lifecycleMappingMetadata>
+					</configuration>
+				</plugin>
 				<!-- Maven Compiler Plugin -->
 				<plugin>
 					<groupId>org.apache.maven.plugins</groupId>
@@ -305,6 +336,31 @@ that you distribute must include a readable copy of the "NOTICE" text file.
 						<quiet>true</quiet>						
 					</configuration>
 				</plugin>
+				<plugin> <!-- Override outdated versions from OSS -->
+					<groupId>org.apache.maven.plugins</groupId>
+					<artifactId>maven-release-plugin</artifactId>
+					<version>2.5.3</version>
+				</plugin>
+				<plugin>
+					<groupId>org.apache.maven.plugins</groupId>
+					<artifactId>maven-enforcer-plugin</artifactId>
+					<version>1.4.1</version>
+				</plugin>
+				<plugin>
+					<groupId>org.apache.maven.plugins</groupId>
+					<artifactId>maven-source-plugin</artifactId>
+					<version>2.4</version>
+				</plugin>
+				<plugin>
+					<groupId>org.apache.maven.plugins</groupId>
+					<artifactId>maven-javadoc-plugin</artifactId>
+					<version>2.10.3</version>
+				</plugin>
+				<plugin>
+					<groupId>org.apache.maven.plugins</groupId>
+					<artifactId>maven-gpg-plugin</artifactId>
+					<version>1.6</version>
+				</plugin>
 			</plugins>
 		</pluginManagement>
 		<plugins>