[hotfix] [core] Fix remaining checkstyle issues for 'core.fs'

flink-core/src/main/java/org/apache/flink/core/fs/FileSystem.java

@@ -229,7 +229,9 @@ public abstract class FileSystem {
 
 	/** The default filesystem scheme to be used, configured during process-wide initialization.
 	 * This value defaults to the local file systems scheme {@code 'file:///'} or {@code 'file:/'}. */
+	//CHECKSTYLE.OFF: StaticVariableName
 	private static URI DEFAULT_SCHEME;
+	//CHECKSTYLE.ON: StaticVariableName
 
 	// ------------------------------------------------------------------------
 	//  Initialization

flink-core/src/main/java/org/apache/flink/core/fs/FileSystemSafetyNet.java

@@ -62,7 +62,7 @@ import static org.apache.flink.util.Preconditions.checkState;
 @Internal
 public class FileSystemSafetyNet {
 
-	/** The map from thread to the safety net registry for that thread */
+	/** The map from thread to the safety net registry for that thread. */
 	private static final ThreadLocal<SafetyNetCloseableRegistry> REGISTRIES = new ThreadLocal<>();
 
 	// ------------------------------------------------------------------------

flink-core/src/main/java/org/apache/flink/core/fs/SafetyNetCloseableRegistry.java

@@ -39,13 +39,13 @@ import java.util.Map;
 /**
  * This implementation of an {@link AbstractCloseableRegistry} registers {@link WrappingProxyCloseable}. When
  * the proxy becomes subject to GC, this registry takes care of closing unclosed {@link Closeable}s.
- * <p>
- * Phantom references are used to track when {@link org.apache.flink.util.WrappingProxy}s of {@link Closeable} got
+ *
+ * <p>Phantom references are used to track when {@link org.apache.flink.util.WrappingProxy}s of {@link Closeable} got
  * GC'ed. We ensure that the wrapped {@link Closeable} is properly closed to avoid resource leaks.
- * <p>
- * Other than that, it works like a normal {@link CloseableRegistry}.
- * <p>
- * All methods in this class are thread-safe.
+ *
+ * <p>Other than that, it works like a normal {@link CloseableRegistry}.
+ *
+ * <p>All methods in this class are thread-safe.
  */
 @Internal
 public class SafetyNetCloseableRegistry extends
@@ -54,15 +54,19 @@ public class SafetyNetCloseableRegistry extends
 
 	private static final Logger LOG = LoggerFactory.getLogger(SafetyNetCloseableRegistry.class);
 
-	/** Lock for atomic modifications to reaper thread and registry count */
+	/** Lock for atomic modifications to reaper thread and registry count. */
 	private static final Object REAPER_THREAD_LOCK = new Object();
 
-	/** Singleton reaper thread takes care of all registries in VM */
+	//CHECKSTYLE.OFF: StaticVariableName
+
+	/** Singleton reaper thread takes care of all registries in VM. */
 	private static CloseableReaperThread REAPER_THREAD = null;
 
-	/** Global count of all instances of SafetyNetCloseableRegistry */
+	/** Global count of all instances of SafetyNetCloseableRegistry. */
 	private static int GLOBAL_SAFETY_NET_REGISTRY_COUNT = 0;
 
+	//CHECKSTYLE.ON: StaticVariableName
+
 	SafetyNetCloseableRegistry() {
 		super(new IdentityHashMap<>());
 
@@ -166,7 +170,7 @@ public class SafetyNetCloseableRegistry extends
 	}
 
 	/**
-	 * Reaper runnable collects and closes leaking resources
+	 * Reaper runnable collects and closes leaking resources.
 	 */
 	static final class CloseableReaperThread extends Thread {
 

flink-core/src/main/java/org/apache/flink/core/fs/SafetyNetWrapperFileSystem.java

@@ -82,6 +82,7 @@ public class SafetyNetWrapperFileSystem extends FileSystem implements WrappingPr
 	}
 
 	@Override
+	@SuppressWarnings("deprecation")
 	public long getDefaultBlockSize() {
 		return unsafeFileSystem.getDefaultBlockSize();
 	}
@@ -107,6 +108,7 @@ public class SafetyNetWrapperFileSystem extends FileSystem implements WrappingPr
 	}
 
 	@Override
+	@SuppressWarnings("deprecation")
 	public FSDataOutputStream create(Path f, boolean overwrite, int bufferSize, short replication, long blockSize)
 			throws IOException {
 

flink-core/src/main/java/org/apache/flink/core/fs/local/LocalBlockLocation.java

@@ -18,11 +18,11 @@
 
 package org.apache.flink.core.fs.local;
 
-import java.io.IOException;
-
 import org.apache.flink.annotation.Internal;
 import org.apache.flink.core.fs.BlockLocation;
 
+import java.io.IOException;
+
 /**
  * Implementation of the {@link BlockLocation} interface for a local file system.
  */

flink-core/src/main/java/org/apache/flink/core/fs/local/LocalDataInputStream.java

@@ -22,6 +22,7 @@ import org.apache.flink.annotation.Internal;
 import org.apache.flink.core.fs.FSDataInputStream;
 
 import javax.annotation.Nonnull;
+
 import java.io.File;
 import java.io.FileInputStream;
 import java.io.IOException;

flink-core/src/main/java/org/apache/flink/core/fs/local/LocalDataOutputStream.java

@@ -18,13 +18,13 @@
 
 package org.apache.flink.core.fs.local;
 
+import org.apache.flink.annotation.Internal;
+import org.apache.flink.core.fs.FSDataOutputStream;
+
 import java.io.File;
 import java.io.FileOutputStream;
 import java.io.IOException;
 
-import org.apache.flink.annotation.Internal;
-import org.apache.flink.core.fs.FSDataOutputStream;
-
 /**
  * The <code>LocalDataOutputStream</code> class is a wrapper class for a data
  * output stream to the local file system.
@@ -62,7 +62,6 @@ public class LocalDataOutputStream extends FSDataOutputStream {
 		fos.close();
 	}
 
-
 	@Override
 	public void flush() throws IOException {
 		fos.flush();

flink-core/src/main/java/org/apache/flink/core/fs/local/LocalFileStatus.java

@@ -16,16 +16,15 @@
  * limitations under the License.
  */
 
-
 package org.apache.flink.core.fs.local;
 
-import java.io.File;
-
 import org.apache.flink.annotation.Internal;
 import org.apache.flink.core.fs.FileStatus;
 import org.apache.flink.core.fs.FileSystem;
 import org.apache.flink.core.fs.Path;
 
+import java.io.File;
+
 /**
  * The class <code>LocalFileStatus</code> provides an implementation of the {@link FileStatus} interface
  * for the local file system.

flink-core/src/main/java/org/apache/flink/core/fs/local/LocalFileSystem.java

@@ -16,10 +16,10 @@
  * limitations under the License.
  */
 
-
-/**
- * This file is based on source code from the Hadoop Project (http://hadoop.apache.org/), licensed by the Apache
- * Software Foundation (ASF) under the Apache License, Version 2.0. See the NOTICE file distributed with this work for
+/*
+ * Parts of earlier versions of this file were based on source code from the
+ * Hadoop Project (http://hadoop.apache.org/), licensed by the Apache Software Foundation (ASF)
+ * under the Apache License, Version 2.0. See the NOTICE file distributed with this work for
  * additional information regarding copyright ownership.
  */
 
@@ -65,7 +65,7 @@ public class LocalFileSystem extends FileSystem {
 	/** The URI representing the local file system. */
 	private static final URI LOCAL_URI = OperatingSystem.isWindows() ? URI.create("file:/") : URI.create("file:///");
 
-	/** The shared instance of the local file system */
+	/** The shared instance of the local file system. */
 	private static final LocalFileSystem INSTANCE = new LocalFileSystem();
 
 	/** Path pointing to the current working directory.
@@ -73,10 +73,10 @@ public class LocalFileSystem extends FileSystem {
 	private final String workingDir;
 
 	/** Path pointing to the current working directory.
-	 * Because Paths are not immutable, we cannot cache the proper path here */
+	 * Because Paths are not immutable, we cannot cache the proper path here. */
 	private final String homeDir;
 
-	/** The host name of this machine */
+	/** The host name of this machine. */
 	private final String hostName;
 
 	/**
@@ -112,7 +112,7 @@ public class LocalFileSystem extends FileSystem {
 		}
 		else {
 			throw new FileNotFoundException("File " + f + " does not exist or the user running "
-					+ "Flink ('"+System.getProperty("user.name")+"') has insufficient permissions to access it.");
+					+ "Flink ('" + System.getProperty("user.name") + "') has insufficient permissions to access it.");
 		}
 	}
 
@@ -149,7 +149,6 @@ public class LocalFileSystem extends FileSystem {
 		return new File(path.toUri().getPath());
 	}
 
-
 	@Override
 	public FileStatus[] listStatus(final Path f) throws IOException {
 
@@ -175,7 +174,6 @@ public class LocalFileSystem extends FileSystem {
 		return results;
 	}
 
-
 	@Override
 	public boolean delete(final Path f, final boolean recursive) throws IOException {
 
@@ -233,7 +231,7 @@ public class LocalFileSystem extends FileSystem {
 	public boolean mkdirs(final Path f) throws IOException {
 		final File p2f = pathToFile(f);
 
-		if(p2f.isDirectory()) {
+		if (p2f.isDirectory()) {
 			return true;
 		}
 

flink-core/src/test/java/org/apache/flink/core/fs/AbstractCloseableRegistryTest.java

@@ -32,6 +32,9 @@ import static org.mockito.Mockito.doAnswer;
 import static org.mockito.Mockito.verify;
 import static org.powermock.api.mockito.PowerMockito.spy;
 
+/**
+ * Tests for the {@link AbstractCloseableRegistry}.
+ */
 public abstract class AbstractCloseableRegistryTest<C extends Closeable, T> {
 
 	protected ProducerThread[] streamOpenThreads;
@@ -140,8 +143,7 @@ public abstract class AbstractCloseableRegistryTest<C extends Closeable, T> {
 		try {
 			closeableRegistry.registerCloseable(testCloseable);
 			Assert.fail("Closed registry should not accept closeables!");
-		}catch (IOException ignore) {
-		}
+		} catch (IOException ignored) {}
 
 		blockCloseLatch.trigger();
 		closer.join();
@@ -151,7 +153,10 @@ public abstract class AbstractCloseableRegistryTest<C extends Closeable, T> {
 		Assert.assertEquals(0, closeableRegistry.getNumberOfRegisteredCloseables());
 	}
 
-	protected static abstract class ProducerThread<C extends Closeable, T> extends Thread {
+	/**
+	 * A testing producer.
+	 */
+	protected abstract static class ProducerThread<C extends Closeable, T> extends Thread {
 
 		protected final AbstractCloseableRegistry<C, T> registry;
 		protected final AtomicInteger refCount;
@@ -188,6 +193,9 @@ public abstract class AbstractCloseableRegistryTest<C extends Closeable, T> {
 		}
 	}
 
+	/**
+	 * Testing stream which adds itself to a reference counter while not closed.
+	 */
 	protected static final class TestStream extends FSDataInputStream {
 
 		protected AtomicInteger refCount;

flink-core/src/test/java/org/apache/flink/core/fs/CloseableRegistryTest.java

@@ -24,6 +24,9 @@ import java.io.Closeable;
 import java.io.IOException;
 import java.util.concurrent.atomic.AtomicInteger;
 
+/**
+ * Tests for the {@link CloseableRegistry}.
+ */
 public class CloseableRegistryTest extends AbstractCloseableRegistryTest<Closeable, Object> {
 
 	@Override

flink-core/src/test/java/org/apache/flink/core/fs/FileSystemTest.java

@@ -15,10 +15,12 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
+
 package org.apache.flink.core.fs;
 
 import org.apache.flink.core.fs.local.LocalFileSystem;
 import org.apache.flink.util.WrappingProxyUtil;
+
 import org.junit.Test;
 
 import java.io.IOException;
@@ -27,6 +29,9 @@ import java.net.URISyntaxException;
 
 import static org.junit.Assert.assertTrue;
 
+/**
+ * Tests for the {@link FileSystem} base class.
+ */
 public class FileSystemTest {
 
 	@Test

flink-core/src/test/java/org/apache/flink/core/fs/InitOutputPathTest.java

@@ -28,7 +28,6 @@ import org.junit.Rule;
 import org.junit.Test;
 import org.junit.rules.TemporaryFolder;
 import org.junit.runner.RunWith;
-
 import org.mockito.invocation.InvocationOnMock;
 import org.mockito.stubbing.Answer;
 import org.powermock.core.classloader.annotations.PrepareForTest;
@@ -40,9 +39,12 @@ import java.io.IOException;
 import java.lang.reflect.Field;
 import java.util.concurrent.locks.ReentrantLock;
 
-import static org.powermock.api.mockito.PowerMockito.*;
-import static org.junit.Assert.*;
+import static org.junit.Assert.fail;
+import static org.powermock.api.mockito.PowerMockito.whenNew;
 
+/**
+ * A test validating that the initialization of local output paths is properly synchronized.
+ */
 @RunWith(PowerMockRunner.class)
 @PrepareForTest(LocalFileSystem.class)
 public class InitOutputPathTest {

flink-core/src/test/java/org/apache/flink/core/fs/LimitedConnectionsFileSystemDelegationTest.java

@@ -28,7 +28,6 @@ import java.io.IOException;
 import java.util.Random;
 
 import static org.junit.Assert.assertEquals;
-
 import static org.mockito.Matchers.any;
 import static org.mockito.Matchers.anyBoolean;
 import static org.mockito.Matchers.anyInt;

flink-core/src/test/java/org/apache/flink/core/fs/LimitedConnectionsFileSystemTest.java

@@ -627,7 +627,7 @@ public class LimitedConnectionsFileSystemTest {
 		}
 	}
 
-	private static abstract class BlockingThread extends CheckedThread {
+	private abstract static class BlockingThread extends CheckedThread {
 
 		private final OneShotLatch waiter = new OneShotLatch();
 

flink-core/src/test/java/org/apache/flink/core/fs/PathTest.java

@@ -15,13 +15,23 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
+
 package org.apache.flink.core.fs;
 
+import org.junit.Test;
+
 import java.io.IOException;
 import java.net.URI;
-import org.junit.Test;
-import static org.junit.Assert.*;
 
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertNull;
+import static org.junit.Assert.assertTrue;
+import static org.junit.Assert.fail;
+
+/**
+ * Tests for the {@link Path} class.
+ */
 public class PathTest {
 
 	@Test
@@ -70,23 +80,23 @@ public class PathTest {
 		assertEquals("/C:/my/windows/path", p.toUri().getPath());
 
 		try {
-			new Path((String)null);
+			new Path((String) null);
 			fail();
-		} catch(Exception e) {
+		} catch (Exception e) {
 			// exception expected
 		}
 
 		try {
 			new Path("");
 			fail();
-		} catch(Exception e) {
+		} catch (Exception e) {
 			// exception expected
 		}
 
 		try {
 			new Path(" ");
 			fail();
-		} catch(Exception e) {
+		} catch (Exception e) {
 			// exception expected
 		}
 

flink-core/src/test/java/org/apache/flink/core/fs/SafetyNetCloseableRegistryTest.java

@@ -32,6 +32,9 @@ import java.io.Closeable;
 import java.io.IOException;
 import java.util.concurrent.atomic.AtomicInteger;
 
+/**
+ * Tests for the {@link SafetyNetCloseableRegistry}.
+ */
 public class SafetyNetCloseableRegistryTest
 	extends AbstractCloseableRegistryTest<WrappingProxyCloseable<? extends Closeable>,
 	SafetyNetCloseableRegistry.PhantomDelegatingCloseableRef> {
@@ -44,9 +47,7 @@ public class SafetyNetCloseableRegistryTest
 		return new WrappingProxyCloseable<Closeable>() {
 
 			@Override
-			public void close() throws IOException {
-
-			}
+			public void close() throws IOException {}
 
 			@Override
 			public Closeable getWrappedDelegate() {

flink-core/src/test/java/org/apache/flink/core/fs/local/LocalFileSystemTest.java

@@ -18,25 +18,13 @@
 
 package org.apache.flink.core.fs.local;
 
-import static org.junit.Assert.assertArrayEquals;
-import static org.junit.Assert.assertEquals;
-import static org.junit.Assert.assertFalse;
-import static org.junit.Assert.assertTrue;
-
-import java.io.File;
-import java.io.FileInputStream;
-import java.io.FileOutputStream;
-import java.io.IOException;
-import java.util.Arrays;
-import java.util.UUID;
-
 import org.apache.flink.core.fs.FSDataInputStream;
 import org.apache.flink.core.fs.FSDataOutputStream;
 import org.apache.flink.core.fs.FileStatus;
 import org.apache.flink.core.fs.FileSystem;
+import org.apache.flink.core.fs.FileSystem.WriteMode;
 import org.apache.flink.core.fs.FileSystemKind;
 import org.apache.flink.core.fs.Path;
-import org.apache.flink.core.fs.FileSystem.WriteMode;
 import org.apache.flink.util.FileUtils;
 
 import org.junit.Assume;
@@ -44,6 +32,18 @@ import org.junit.Rule;
 import org.junit.Test;
 import org.junit.rules.TemporaryFolder;
 
+import java.io.File;
+import java.io.FileInputStream;
+import java.io.FileOutputStream;
+import java.io.IOException;
+import java.util.Arrays;
+import java.util.UUID;
+
+import static org.junit.Assert.assertArrayEquals;
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertTrue;
+
 /**
  * This class tests the functionality of the {@link LocalFileSystem} class in its components. In particular,
  * file/directory access, creation, deletion, read, write is tested.

tools/maven/suppressions-core.xml

@@ -111,14 +111,6 @@ under the License.
 		files="(.*)test[/\\](.*)configuration[/\\](.*)"
 		checks="AvoidStarImport"/>
 
-	<suppress
-		files="(.*)core[/\\]fs[/\\](.*)"
-		checks="NewlineAtEndOfFile|RegexpSingleline|TodoComment|RedundantImport|ImportOrder|RedundantModifier|JavadocMethod|JavadocParagraph|JavadocType|JavadocStyle|PackageName|TypeNameCheck|ConstantNameCheck|StaticVariableNameCheck|MemberNameCheck|MethodNameCheck|ParameterName|LocalFinalVariableName|LocalVariableName|LeftCurly|UpperEll|FallThrough|reliefPattern|SimplifyBooleanExpression|EmptyStatement|ModifierOrder|EmptyLineSeparator|WhitespaceAround|WhitespaceAfter|NoWhitespaceAfter|NoWhitespaceBefore|OperatorWrap|ParenPad"/>
-	<!--Only additional checks for test sources. Those checks were present in the "pre-strict" checkstyle but were not applied to test sources. We do not want to suppress them for sources directory-->
-	<suppress
-		files="(.*)test[/\\](.*)core[/\\]fs[/\\](.*)"
-		checks="AvoidStarImport"/>
-
 	<suppress
 		files="(.*)core[/\\]io[/\\](.*)"
 		checks="NewlineAtEndOfFile|RegexpSingleline|TodoComment|RedundantImport|ImportOrder|RedundantModifier|JavadocMethod|JavadocParagraph|JavadocType|JavadocStyle|PackageName|TypeNameCheck|ConstantNameCheck|StaticVariableNameCheck|MemberNameCheck|MethodNameCheck|ParameterName|LocalFinalVariableName|LocalVariableName|LeftCurly|UpperEll|FallThrough|reliefPattern|SimplifyBooleanExpression|EmptyStatement|ModifierOrder|EmptyLineSeparator|WhitespaceAround|WhitespaceAfter|NoWhitespaceAfter|NoWhitespaceBefore|OperatorWrap|ParenPad"/>