Merge pull request #37 from saalfeldlab/perf/skipIsFile

perf: throw N5NoSuchKeyException if no key when reading

pom.xml

@@ -5,7 +5,7 @@
 	<parent>
 		<groupId>org.scijava</groupId>
 		<artifactId>pom-scijava</artifactId>
-		<version>37.0.0</version>
+		<version>38.0.1</version>
 		<relativePath />
 	</parent>
 
@@ -120,7 +120,7 @@
 
 		<s3mock_2.12.version>0.2.5</s3mock_2.12.version>
 		<jaxb-api.version>2.2.2</jaxb-api.version>
-		<n5.version>3.2.0</n5.version>
+		<n5.version>3.3.0</n5.version>
 	</properties>
 
 	<dependencies>

src/main/java/org/janelia/saalfeldlab/n5/s3/AmazonS3KeyValueAccess.java

@@ -47,7 +47,8 @@
 import java.util.List;
 import java.util.stream.Collectors;
 
-import com.amazonaws.services.s3.AmazonS3URI;
+import com.amazonaws.AmazonServiceException;
+import com.amazonaws.services.s3.model.S3Object;
 import org.janelia.saalfeldlab.n5.KeyValueAccess;
 import org.janelia.saalfeldlab.n5.LockedChannel;
 import org.janelia.saalfeldlab.n5.N5Exception;
@@ -602,7 +603,15 @@ private void checkWritable() {
 		@Override
 		public InputStream newInputStream() {
 
-			final S3ObjectInputStream in = s3.getObject(bucketName, path).getObjectContent();
+			final S3Object object;
+			try {
+				object = s3.getObject(bucketName, path);
+			} catch (final AmazonServiceException e) {
+				if (e.getStatusCode() == 404)
+					throw new N5Exception.N5NoSuchKeyException("No such key", e);
+				throw e;
+			}
+			final S3ObjectInputStream in = object.getObjectContent();
 			final S3ObjectInputStreamDrain s3in = new S3ObjectInputStreamDrain(in);
 			synchronized (resources) {
 				resources.add(s3in);