Provide a valid class loader even if there is none from thread context

Fixes #131
tinylog-org · Feb 3, 2020 · 08afcca · 08afcca
1 parent 7d1651c
commit 08afcca
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Showing 4 changed files with 50 additions and 3 deletions.
diff --git a/tinylog-api/src/main/java/org/tinylog/configuration/Configuration.java b/tinylog-api/src/main/java/org/tinylog/configuration/Configuration.java
@@ -28,6 +28,7 @@
 
 import org.tinylog.Level;
 import org.tinylog.provider.InternalLogger;
+import org.tinylog.runtime.RuntimeProvider;
 
 /**
  * Global configuration for tinylog.
@@ -212,7 +213,7 @@ private static Properties load() {
 				if (URL_DETECTION_PATTERN.matcher(file).matches()) {
 					stream = new URL(file).openStream();
 				} else {
-					stream = Thread.currentThread().getContextClassLoader().getResourceAsStream(file);
+					stream = RuntimeProvider.getClassLoader().getResourceAsStream(file);
 					if (stream == null) {
 						stream = new FileInputStream(file);
 					}
@@ -221,7 +222,7 @@ private static Properties load() {
 			} else {
 				for (String configurationFile : CONFIGURATION_FILES) {
 					file = configurationFile;
-					InputStream stream = Thread.currentThread().getContextClassLoader().getResourceAsStream(file);
+					InputStream stream = RuntimeProvider.getClassLoader().getResourceAsStream(file);
 					if (stream != null) {
 						load(properties, stream);
 						break;

diff --git a/tinylog-api/src/main/java/org/tinylog/configuration/ServiceLoader.java b/tinylog-api/src/main/java/org/tinylog/configuration/ServiceLoader.java
@@ -28,6 +28,7 @@
 
 import org.tinylog.Level;
 import org.tinylog.provider.InternalLogger;
+import org.tinylog.runtime.RuntimeProvider;
 
 /**
  * Alternative service loader that supports constructors with arguments in opposite to {@link java.util.ServiceLoader}.
@@ -55,7 +56,7 @@ public final class ServiceLoader<T> {
 	public ServiceLoader(final Class<? extends T> service, final Class<?>... argumentTypes) {
 		this.service = service;
 		this.argumentTypes = argumentTypes;
-		this.classLoader = Thread.currentThread().getContextClassLoader();
+		this.classLoader = RuntimeProvider.getClassLoader();
 		this.classes = loadClasses(classLoader, service);
 	}
 

diff --git a/tinylog-api/src/main/java/org/tinylog/runtime/RuntimeProvider.java b/tinylog-api/src/main/java/org/tinylog/runtime/RuntimeProvider.java
@@ -29,6 +29,21 @@ public final class RuntimeProvider {
 	private RuntimeProvider() {
 	}
 
+	/**
+	 * Gets a valid class loader.
+	 *
+	 * @return Valid class loader instance
+	 */
+	public static ClassLoader getClassLoader() {
+		ClassLoader classLoader = Thread.currentThread().getContextClassLoader();
+
+		if (classLoader == null) {
+			classLoader = RuntimeProvider.class.getClassLoader();
+		}
+
+		return classLoader;
+	}
+
 	/**
 	 * Gets the name of the default writer.
 	 *

diff --git a/tinylog-api/src/test/java/org/tinylog/runtime/RuntimeProviderTest.java b/tinylog-api/src/test/java/org/tinylog/runtime/RuntimeProviderTest.java
@@ -23,6 +23,7 @@
 import org.tinylog.util.SimpleTimestamp;
 
 import static org.assertj.core.api.Assertions.assertThat;
+import static org.mockito.Mockito.mock;
 
 /**
  * Tests for {@link RuntimeProvider}.
@@ -56,6 +57,35 @@ public void reset() throws Exception {
 		Whitebox.setInternalState(RuntimeProvider.class, RuntimeDialect.class, dialect);
 	}
 
+	/**
+	 * Verifies that the thread context class loader will be returned, if available.
+	 */
+	@Test
+	public void classLoaderFromThread() {
+		ClassLoader classLoader = Thread.currentThread().getContextClassLoader();
+		try {
+			ClassLoader mock = mock(ClassLoader.class);
+			Thread.currentThread().setContextClassLoader(mock);
+			assertThat(RuntimeProvider.getClassLoader()).isSameAs(mock);
+		} finally {
+			Thread.currentThread().setContextClassLoader(classLoader);
+		}
+	}
+
+	/**
+	 * Verifies that a class loader will be returned, even if there is no thread context class loader.
+	 */
+	@Test
+	public void classLoaderNotFromThread() {
+		ClassLoader classLoader = Thread.currentThread().getContextClassLoader();
+		try {
+			Thread.currentThread().setContextClassLoader(null);
+			assertThat(RuntimeProvider.getClassLoader()).isNotNull();
+		} finally {
+			Thread.currentThread().setContextClassLoader(classLoader);
+		}
+	}
+
 	/**
 	 * Verifies that the name of a default writer will be returned.
 	 */