Add checkstyle configuration based on Google Java style

.git-blame-ignore-revs

@@ -0,0 +1,2 @@
+# Format source code according to checkstyle configuration
+a5da2cad2e1f73c18df90bbfbe5d06f2bbd3357e

build.gradle

@@ -2,6 +2,7 @@ plugins {
     id 'java-library'
     id 'eclipse'
     id 'maven-publish'
+    id 'checkstyle'
 }
 
 group = 'com.glencoesoftware.omero'
@@ -87,3 +88,7 @@ jar {
         )
     }
 }
+
+checkstyle {
+    toolVersion = "10.26.1"
+}

src/main/java/com/glencoesoftware/omero/zarr/OmeroAmazonS3ClientFactory.java

@@ -15,14 +15,8 @@
  * with this program; if not, write to the Free Software Foundation, Inc.,
  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  */
-package com.glencoesoftware.omero.zarr;
 
-import java.net.URI;
-import java.util.HashMap;
-import java.util.Map;
-import java.util.Properties;
-
-import org.slf4j.LoggerFactory;
+package com.glencoesoftware.omero.zarr;
 
 import com.amazonaws.auth.AWSCredentialsProvider;
 import com.amazonaws.auth.AWSCredentialsProviderChain;
@@ -36,7 +30,15 @@
 import com.amazonaws.services.s3.AmazonS3ClientBuilder;
 import com.amazonaws.util.AwsHostNameUtils;
 import com.upplication.s3fs.AmazonS3ClientFactory;
+import java.net.URI;
+import java.util.HashMap;
+import java.util.Map;
+import java.util.Properties;
+import org.slf4j.LoggerFactory;
 
+/**
+ * Subclass which maps an URI into a set of credentials to use for the client.
+ */
 public class OmeroAmazonS3ClientFactory extends AmazonS3ClientFactory {
 
     private static final org.slf4j.Logger log =
@@ -48,11 +50,11 @@ public class OmeroAmazonS3ClientFactory extends AmazonS3ClientFactory {
     protected AWSCredentialsProvider getCredentialsProvider(Properties props) {
         // If AWS Environment or System Properties are set, throw an exception
         // so users will know they are not supported
-        if (System.getenv("AWS_ACCESS_KEY_ID") != null ||
-                System.getenv("AWS_SECRET_ACCESS_KEY") != null ||
-                System.getenv("AWS_SESSION_TOKEN") != null ||
-                System.getProperty("aws.accessKeyId") != null ||
-                System.getProperty("aws.secretAccessKey") != null) {
+        if (System.getenv("AWS_ACCESS_KEY_ID") != null
+                || System.getenv("AWS_SECRET_ACCESS_KEY") != null
+                || System.getenv("AWS_SESSION_TOKEN") != null
+                || System.getProperty("aws.accessKeyId") != null
+                || System.getProperty("aws.secretAccessKey") != null) {
             throw new RuntimeException("AWS credentials supplied by environment variables"
                     + " or Java system properties are not supported."
                     + " Please use either named profiles or instance"
@@ -77,6 +79,7 @@ protected AWSCredentialsProvider getCredentialsProvider(Properties props) {
 
     /**
      * Retrieves the bucket name from a given URI.
+     *
      * @param uri The URI to handle
      * @return The bucket name
      */
@@ -90,6 +93,7 @@ private String getBucketFromUri(URI uri) {
 
     /**
      * Retrieves the region from a given URI.
+     *
      * @param uri The URI to handle
      * @return The region
      */
@@ -103,6 +107,7 @@ private String getRegionFromUri(URI uri) {
 
     /**
      * Retrieves the endpoint from a given URI.
+     *
      * @param uri The URI to handle
      * @return The endpoint
      */
@@ -112,19 +117,20 @@ public String getEndPointFromUri(URI uri) {
 
     @Override
     public synchronized AmazonS3 getAmazonS3(URI uri, Properties props) {
-        //Check if we have a S3 client for this bucket
+        // Check if we have a S3 client for this bucket
         String bucket = getBucketFromUri(uri);
         if (bucketClientMap.containsKey(bucket)) {
             log.info("Found bucket " + bucket);
             return bucketClientMap.get(bucket);
         }
         log.info("Creating client for bucket " + bucket);
         AmazonS3 client = AmazonS3ClientBuilder.standard()
-                            .withCredentials(getCredentialsProvider(props))
-                            .withClientConfiguration(getClientConfiguration(props))
-                            .withMetricsCollector(getRequestMetricsCollector(props))
-                            .withEndpointConfiguration(new EndpointConfiguration(getEndPointFromUri(uri), getRegionFromUri(uri)))
-                            .build();
+            .withCredentials(getCredentialsProvider(props))
+            .withClientConfiguration(getClientConfiguration(props))
+            .withMetricsCollector(getRequestMetricsCollector(props))
+            .withEndpointConfiguration(
+                new EndpointConfiguration(getEndPointFromUri(uri), getRegionFromUri(uri)))
+            .build();
         bucketClientMap.put(bucket, client);
         return client;
     }

src/main/java/com/glencoesoftware/omero/zarr/OmeroS3FileSystem.java

@@ -15,28 +15,30 @@
  * with this program; if not, write to the Free Software Foundation, Inc.,
  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  */
-package com.glencoesoftware.omero.zarr;
 
-import java.io.IOException;
+package com.glencoesoftware.omero.zarr;
 
 import com.amazonaws.services.s3.AmazonS3;
 import com.upplication.s3fs.S3FileSystem;
 import com.upplication.s3fs.S3FileSystemProvider;
+import java.io.IOException;
 
+/** Subclass of S3FileSystem with performance optimizations. */
 public class OmeroS3FileSystem extends S3FileSystem {
 
+    /** Default constructor. */
     public OmeroS3FileSystem(S3FileSystemProvider provider, String key,
             AmazonS3 client, String endpoint) {
         super(provider, key, client, endpoint);
     }
 
     @Override
     public void close() throws IOException {
-        //No-op
+        // No-op
     }
 
     @Override
     public boolean isOpen() {
-        return true; //Not possible to be closed
+        return true; // Not possible to be closed
     }
 }

src/main/java/com/glencoesoftware/omero/zarr/OmeroS3ReadOnlySeekableByteChannel.java

@@ -15,9 +15,14 @@
  * with this program; if not, write to the Free Software Foundation, Inc.,
  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  */
-package com.glencoesoftware.omero.zarr;
 
+package com.glencoesoftware.omero.zarr;
 
+import com.amazonaws.services.s3.model.GetObjectRequest;
+import com.amazonaws.services.s3.model.S3Object;
+import com.amazonaws.services.s3.model.S3ObjectInputStream;
+import com.upplication.s3fs.S3Path;
+import com.upplication.s3fs.S3ReadOnlySeekableByteChannel;
 import java.io.ByteArrayInputStream;
 import java.io.ByteArrayOutputStream;
 import java.io.IOException;
@@ -32,14 +37,8 @@
 import java.util.Collections;
 import java.util.HashSet;
 import java.util.Set;
-
 import org.perf4j.slf4j.Slf4JStopWatch;
 
-import com.amazonaws.services.s3.model.GetObjectRequest;
-import com.amazonaws.services.s3.model.S3Object;
-import com.amazonaws.services.s3.model.S3ObjectInputStream;
-import com.upplication.s3fs.S3Path;
-import com.upplication.s3fs.S3ReadOnlySeekableByteChannel;
 
 /**
  * Overridden, hybrid version of the implementation from
@@ -61,15 +60,15 @@ public class OmeroS3ReadOnlySeekableByteChannel implements SeekableByteChannel {
      * entire object in full from S3 without checks for length during
      * object construction.
      */
-    public OmeroS3ReadOnlySeekableByteChannel(S3Path path, Set<? extends OpenOption> options) throws IOException {
+    public OmeroS3ReadOnlySeekableByteChannel(S3Path path, Set<? extends OpenOption> options)
+          throws IOException {
         this.options = Collections.unmodifiableSet(new HashSet<>(options));
 
-        if (
-            this.options.contains(StandardOpenOption.WRITE) ||
-            this.options.contains(StandardOpenOption.CREATE) ||
-            this.options.contains(StandardOpenOption.CREATE_NEW) ||
-            this.options.contains(StandardOpenOption.APPEND)
-        ) {
+        if (this.options.contains(StandardOpenOption.WRITE)
+                || this.options.contains(StandardOpenOption.CREATE)
+                || this.options.contains(StandardOpenOption.CREATE_NEW)
+                || this.options.contains(StandardOpenOption.APPEND)
+            ) {
             throw new ReadOnlyFileSystemException();
         }
 
@@ -92,10 +91,10 @@ public OmeroS3ReadOnlySeekableByteChannel(S3Path path, Set<? extends OpenOption>
             // the stream closed as quickly as possible. See
             // https://docs.aws.amazon.com/AWSJavaSDK/latest/javadoc/com/amazonaws/services/s3/model/S3Object.html#getObjectContent--
             try (S3ObjectInputStream s3Stream = s3Object.getObjectContent()) {
-                byte[] read_buf = new byte[1024*1024];
-                int read_len = 0;
-                while ((read_len = s3Stream.read(read_buf)) > 0) {
-                    outputStream.write(read_buf, 0, read_len);
+                byte[] readBuf = new byte[1024 * 1024];
+                int readLen = 0;
+                while ((readLen = s3Stream.read(readBuf)) > 0) {
+                    outputStream.write(readBuf, 0, readLen);
                 }
             }
             this.data = outputStream.toByteArray();
@@ -124,7 +123,9 @@ public boolean isOpen() {
      * private visibility.
      */
     @Override
-    public long position() { return position; }
+    public long position() {
+        return position;
+    }
 
     /**
      * Overridden, hybrid version of the implementation from
@@ -133,8 +134,7 @@ public boolean isOpen() {
      */
     @Override
     public SeekableByteChannel position(long targetPosition)
-            throws IOException
-    {
+            throws IOException {
         throw new UnsupportedOperationException();
     }