guava-14.0-vs-18.0-classloader.java

// Guava 14.0 - bundled with Spark
// https://github.com/google/guava/blob/v14.0/guava/src/com/google/common/io/Resources.java#L191
/**
 * Returns a {@code URL} pointing to {@code resourceName} if the resource is
 * found in the class path. {@code Resources.class.getClassLoader()} is used
 * to locate the resource.
 */
public static URL getResource(String resourceName) {
    URL url = Resources.class.getClassLoader().getResource(resourceName);
    checkArgument(url != null, "resource %s not found.", resourceName);
    return url;
}

// --------------------------------------------------------------------------------------------------------------------------
// Guava 18.0 - dependency for embedded-redis
// https://github.com/google/guava/blob/v18.0/guava/src/com/google/common/io/Resources.java

/**
 * Returns a {@code URL} pointing to {@code resourceName} if the resource is
 * found using the {@linkplain Thread#getContextClassLoader() context class
 * loader}. In simple environments, the context class loader will find
 * resources from the class path. In environments where different threads can
 * have different class loaders, for example app servers, the context class
 * loader will typically have been set to an appropriate loader for the
 * current thread.
 *
 * <p>In the unusual case where the context class loader is null, the class
 * loader that loaded this class ({@code Resources}) will be used instead.
 * 
 */
public static URL getResource(String resourceName) {
  ClassLoader loader = MoreObjects.firstNonNull(
      Thread.currentThread().getContextClassLoader(),
      Resources.class.getClassLoader());
  URL url = loader.getResource(resourceName);
  checkArgument(url != null, "resource %s not found.", resourceName);
  return url;
}