[hotfix] [core] Fix lots of checkstyle errors in core.fs

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

@@ -32,13 +32,13 @@ import java.io.IOException;
 @Internal
 public abstract class AbstractMultiFSDataInputStream extends FSDataInputStream {
 
-	/** Inner stream for the currently accessed segment of the virtual global stream */
+	/** Inner stream for the currently accessed segment of the virtual global stream. */
 	protected FSDataInputStream delegate;
 
-	/** Position in the virtual global stream */
+	/** Position in the virtual global stream. */
 	protected long totalPos;
 
-	/** Total available bytes in the virtual global stream */
+	/** Total available bytes in the virtual global stream. */
 	protected long totalAvailable;
 
 	public AbstractMultiFSDataInputStream() {
@@ -48,7 +48,7 @@ public abstract class AbstractMultiFSDataInputStream extends FSDataInputStream {
 	@Override
 	public void seek(long desired) throws IOException {
 
-		if(desired == totalPos) {
+		if (desired == totalPos) {
 			return;
 		}
 

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

@@ -30,7 +30,7 @@ public interface BlockLocation extends Comparable<BlockLocation> {
 
 	/**
 	 * Get the list of hosts (hostname) hosting this block.
-	 * 
+	 *
 	 * @return A list of hosts (hostname) hosting this block.
 	 * @throws IOException
 	 *         thrown if the list of hosts could not be retrieved
@@ -39,14 +39,14 @@ public interface BlockLocation extends Comparable<BlockLocation> {
 
 	/**
 	 * Get the start offset of the file associated with this block.
-	 * 
+	 *
 	 * @return The start offset of the file associated with this block.
 	 */
 	long getOffset();
 
 	/**
 	 * Get the length of the block.
-	 * 
+	 *
 	 * @return the length of the block
 	 */
 	long getLength();

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

@@ -29,10 +29,10 @@ import java.util.Map;
 
 /**
  * This class allows to register instances of {@link Closeable}, which are all closed if this registry is closed.
- * <p>
- * Registering to an already closed registry will throw an exception and close the provided {@link Closeable}
- * <p>
- * All methods in this class are thread-safe.
+ *
+ * <p>Registering to an already closed registry will throw an exception and close the provided {@link Closeable}
+ *
+ * <p>All methods in this class are thread-safe.
  */
 @Internal
 public class CloseableRegistry extends AbstractCloseableRegistry<Closeable, Object> {

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

@@ -26,8 +26,8 @@ import java.io.IOException;
 /**
  * This class is a {@link org.apache.flink.util.WrappingProxy} for {@link FSDataInputStream} that is used to
  * implement a safety net against unclosed streams.
- * <p>
- * See {@link SafetyNetCloseableRegistry} for more details on how this is utilized.
+ *
+ * <p>See {@link SafetyNetCloseableRegistry} for more details on how this is utilized.
  */
 @Internal
 public class ClosingFSDataInputStream

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

@@ -26,8 +26,8 @@ import java.io.IOException;
 /**
  * This class is a {@link org.apache.flink.util.WrappingProxy} for {@link FSDataOutputStream} that is used to
  * implement a safety net against unclosed streams.
- * <p>
- * See {@link SafetyNetCloseableRegistry} for more details on how this is utilized.
+ *
+ * <p>See {@link SafetyNetCloseableRegistry} for more details on how this is utilized.
  */
 @Internal
 public class ClosingFSDataOutputStream

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

@@ -25,7 +25,7 @@ import java.io.InputStream;
 
 /**
  * Interface for a data input stream to a file on a {@link FileSystem}.
- * 
+ *
  * <p>This extends the {@link java.io.InputStream} with methods for accessing
  * the stream's {@link #getPos() current position} and
  * {@link #seek(long) seeking} to a desired position.
@@ -36,7 +36,7 @@ public abstract class FSDataInputStream extends InputStream {
 	/**
 	 * Seek to the given offset from the start of the file. The next read() will be from that location.
 	 * Can't seek past the end of the file.
-	 * 
+	 *
 	 * @param desired
 	 *        the desired offset
 	 * @throws IOException Thrown if an error occurred while seeking inside the input stream.
@@ -47,7 +47,7 @@ public abstract class FSDataInputStream extends InputStream {
 	 * Gets the current position in the input stream.
 	 *
 	 * @return current position in the input stream
-	 * @throws IOException Thrown if an I/O error occurred in the underlying stream 
+	 * @throws IOException Thrown if an I/O error occurred in the underlying stream
 	 *                     implementation while accessing the stream's position.
 	 */
 	public abstract long getPos() throws IOException;

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

@@ -25,7 +25,7 @@ import org.apache.flink.util.WrappingProxy;
 import java.io.IOException;
 
 /**
- * Simple forwarding wrapper around {@link FSDataInputStream}
+ * Simple forwarding wrapper around {@link FSDataInputStream}.
  */
 @Internal
 public class FSDataInputStreamWrapper extends FSDataInputStream implements WrappingProxy<FSDataInputStream> {

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

@@ -26,22 +26,22 @@ import java.io.OutputStream;
 /**
  * An output stream to a file that is created via a {@link FileSystem}.
  * This class extends the base {@link java.io.OutputStream} with some additional important methods.
- * 
+ *
  * <h2>Data Persistence Guarantees</h2>
- * 
- * These streams are used to persistently store data, both for results of streaming applications
+ *
+ * <p>These streams are used to persistently store data, both for results of streaming applications
  * and for fault tolerance and recovery. It is therefore crucial that the persistence semantics
  * of these streams are well defined.
- * 
+ *
  * <p>Please refer to the class-level docs of {@link FileSystem} for the definition of data persistence
  * via Flink's FileSystem abstraction and the {@code FSDataOutputStream}.
- * 
+ *
  * <h2>Thread Safety</h2>
- * 
- * Implementations of the {@code FSDataOutputStream} are generally not assumed to be thread safe.
+ *
+ * <p>Implementations of the {@code FSDataOutputStream} are generally not assumed to be thread safe.
  * Instances of {@code FSDataOutputStream} should not be passed between threads, because there
  * are no guarantees about the order of visibility of operations across threads.
- * 
+ *
  * @see FileSystem
  * @see FSDataInputStream
  */
@@ -52,13 +52,13 @@ public abstract class FSDataOutputStream extends OutputStream {
 	 * Gets the position of the stream (non-negative), defined as the number of bytes
 	 * from the beginning of the file to the current writing position. The position
 	 * corresponds to the zero-based index of the next byte that will be written.
-	 * 
+	 *
 	 * <p>This method must report accurately report the current position of the stream.
 	 * Various components of the high-availability and recovery logic rely on the accurate
-	 * 
+	 *
 	 * @return The current position in the stream, defined as the number of bytes
 	 *         from the beginning of the file to the current writing position.
-	 * 
+	 *
 	 * @throws IOException Thrown if an I/O error occurs while obtaining the position from
 	 *                     the stream implementation.
 	 */
@@ -68,14 +68,14 @@ public abstract class FSDataOutputStream extends OutputStream {
 	 * Flushes the stream, writing any data currently buffered in stream implementation
 	 * to the proper output stream. After this method has been called, the stream implementation
 	 * must not hold onto any buffered data any more.
-	 * 
+	 *
 	 * <p>A completed flush does not mean that the data is necessarily persistent. Data
 	 * persistence can is only assumed after calls to {@link #close()} or {@link #sync()}.
-	 * 
+	 *
 	 * <p>Implementation note: This overrides the method defined in {@link OutputStream}
 	 * as abstract to force implementations of the {@code FSDataOutputStream} to implement
 	 * this method directly.
-	 * 
+	 *
 	 * @throws IOException Thrown if an I/O error occurs while flushing the stream.
 	 */
 	public abstract void flush() throws IOException;
@@ -84,9 +84,7 @@ public abstract class FSDataOutputStream extends OutputStream {
 	 * Flushes the data all the way to the persistent non-volatile storage (for example disks).
 	 * The method behaves similar to the <i>fsync</i> function, forcing all data to
 	 * be persistent on the devices.
-	 * 
-	 * <p>
-	 * 
+	 *
 	 * @throws IOException Thrown if an I/O error occurs
 	 */
 	public abstract void sync() throws IOException;
@@ -95,20 +93,20 @@ public abstract class FSDataOutputStream extends OutputStream {
 	 * Closes the output stream. After this method returns, the implementation must guarantee
 	 * that all data written to the stream is persistent/visible, as defined in the
 	 * {@link FileSystem class-level docs}.
-	 * 
+	 *
 	 * <p>The above implies that the method must block until persistence can be guaranteed.
 	 * For example for distributed replicated file systems, the method must block until the
 	 * replication quorum has been reached. If the calling thread is interrupted in the
 	 * process, it must fail with an {@code IOException} to indicate that persistence cannot
 	 * be guaranteed.
-	 * 
+	 *
 	 * <p>If this method throws an exception, the data in the stream cannot be assumed to be
 	 * persistent.
-	 * 
+	 *
 	 * <p>Implementation note: This overrides the method defined in {@link OutputStream}
 	 * as abstract to force implementations of the {@code FSDataOutputStream} to implement
 	 * this method directly.
-	 *         
+	 *
 	 * @throws IOException Thrown, if an error occurred while closing the stream or guaranteeing
 	 *                     that the data is persistent.
 	 */

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

@@ -25,7 +25,7 @@ import org.apache.flink.util.WrappingProxy;
 import java.io.IOException;
 
 /**
- * Simple forwarding wrapper around {@link FSDataInputStream}
+ * Simple forwarding wrapper around {@link FSDataInputStream}.
  */
 @Internal
 public class FSDataOutputStreamWrapper extends FSDataOutputStream implements WrappingProxy<FSDataOutputStream> {

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

@@ -23,7 +23,7 @@ import org.apache.flink.core.io.LocatableInputSplit;
 
 /**
  * A file input split provides information on a particular part of a file, possibly
- * hosted on a distributed file system and replicated among several hosts. 
+ * hosted on a distributed file system and replicated among several hosts.
  */
 @Public
 public class FileInputSplit extends LocatableInputSplit {
@@ -34,16 +34,16 @@ public class FileInputSplit extends LocatableInputSplit {
 	private final Path file;
 
 	/** The position of the first byte in the file to process. */
-	private long start;
+	private final long start;
 
 	/** The number of bytes in the file to process. */
-	private long length;
+	private final long length;
 
 	// --------------------------------------------------------------------------------------------
-	
+
 	/**
 	 * Constructs a split with host information.
-	 * 
+	 *
 	 * @param num
 	 *        the number of this input split
 	 * @param file
@@ -57,17 +57,17 @@ public class FileInputSplit extends LocatableInputSplit {
 	 */
 	public FileInputSplit(int num, Path file, long start, long length, String[] hosts) {
 		super(num, hosts);
-		
+
 		this.file = file;
 		this.start = start;
 		this.length = length;
 	}
 
 	// --------------------------------------------------------------------------------------------
-	
+
 	/**
 	 * Returns the path of the file containing this split's data.
-	 * 
+	 *
 	 * @return the path of the file containing this split's data.
 	 */
 	public Path getPath() {
@@ -76,7 +76,7 @@ public class FileInputSplit extends LocatableInputSplit {
 
 	/**
 	 * Returns the position of the first byte in the file to process.
-	 * 
+	 *
 	 * @return the position of the first byte in the file to process
 	 */
 	public long getStart() {
@@ -85,20 +85,20 @@ public class FileInputSplit extends LocatableInputSplit {
 
 	/**
 	 * Returns the number of bytes in the file to process.
-	 * 
+	 *
 	 * @return the number of bytes in the file to process
 	 */
 	public long getLength() {
 		return length;
 	}
-	
+
 	// --------------------------------------------------------------------------------------------
-	
+
 	@Override
 	public int hashCode() {
 		return getSplitNumber() ^ (file == null ? 0 : file.hashCode());
 	}
-	
+
 	@Override
 	public boolean equals(Object obj) {
 		if (obj == this) {
@@ -106,7 +106,7 @@ public class FileInputSplit extends LocatableInputSplit {
 		}
 		else if (obj != null && obj instanceof FileInputSplit && super.equals(obj)) {
 			FileInputSplit other = (FileInputSplit) obj;
-			
+
 			return this.start == other.start &&
 					this.length == other.length &&
 					(this.file == null ? other.file == null : (other.file != null && this.file.equals(other.file)));
@@ -115,7 +115,7 @@ public class FileInputSplit extends LocatableInputSplit {
 			return false;
 		}
 	}
-	
+
 	@Override
 	public String toString() {
 		return "[" + getSplitNumber() + "] " + file + ":" + start + "+" + length;

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

@@ -20,7 +20,7 @@
 /**
  * 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
- * additional information regarding copyright ownership. 
+ * additional information regarding copyright ownership.
  */
 
 package org.apache.flink.core.fs;
@@ -30,56 +30,55 @@ import org.apache.flink.annotation.Public;
 /**
  * Interface that represents the client side information for a file
  * independent of the file system.
- * 
  */
 @Public
 public interface FileStatus {
 
 	/**
-	 * Return the length of this file
-	 * 
+	 * Return the length of this file.
+	 *
 	 * @return the length of this file
 	 */
 	long getLen();
 
 	/**
 	 *Get the block size of the file.
-	 * 
+	 *
 	 * @return the number of bytes
 	 */
 	long getBlockSize();
 
 	/**
 	 * Get the replication factor of a file.
-	 * 
+	 *
 	 * @return the replication factor of a file.
 	 */
 	short getReplication();
 
 	/**
 	 * Get the modification time of the file.
-	 * 
+	 *
 	 * @return the modification time of file in milliseconds since January 1, 1970 UTC.
 	 */
 	long getModificationTime();
 
 	/**
 	 * Get the access time of the file.
-	 * 
+	 *
 	 * @return the access time of file in milliseconds since January 1, 1970 UTC.
 	 */
 	long getAccessTime();
 
 	/**
 	 * Checks if this object represents a directory.
-	 * 
+	 *
 	 * @return <code>true</code> if this is a directory, <code>false</code> otherwise
 	 */
 	boolean isDir();
 
 	/**
 	 * Returns the corresponding Path to the FileStatus.
-	 * 
+	 *
 	 * @return the corresponding Path to the FileStatus
 	 */
 	Path getPath();

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

@@ -58,4 +58,4 @@ public interface FileSystemFactory {
 	 * @throws IOException Thrown if the file system could not be instantiated.
 	 */
 	FileSystem create(URI fsUri) throws IOException;
-}
\ No newline at end of file
+}

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

@@ -22,26 +22,26 @@
 
 package org.apache.flink.core.fs;
 
-import java.io.IOException;
-import java.io.Serializable;
-import java.net.URI;
-import java.net.URISyntaxException;
-
 import org.apache.flink.annotation.Public;
 import org.apache.flink.core.io.IOReadableWritable;
 import org.apache.flink.core.memory.DataInputView;
 import org.apache.flink.core.memory.DataOutputView;
 import org.apache.flink.util.StringUtils;
 
+import java.io.IOException;
+import java.io.Serializable;
+import java.net.URI;
+import java.net.URISyntaxException;
+
 /**
  * Names a file or directory in a {@link FileSystem}. Path strings use slash as
  * the directory separator. A path string is absolute if it begins with a slash.
  *
- * Tailing slashes are removed from the path.
+ * <p>Tailing slashes are removed from the path.
  */
 @Public
 public class Path implements IOReadableWritable, Serializable {
-	
+
 	private static final long serialVersionUID = 1L;
 
 	/**
@@ -71,7 +71,7 @@ public class Path implements IOReadableWritable, Serializable {
 
 	/**
 	 * Constructs a path object from a given URI.
-	 * 
+	 *
 	 * @param uri
 	 *        the URI to construct the path object from
 	 */
@@ -81,7 +81,7 @@ public class Path implements IOReadableWritable, Serializable {
 
 	/**
 	 * Resolve a child path against a parent path.
-	 * 
+	 *
 	 * @param parent
 	 *        the parent path
 	 * @param child
@@ -93,7 +93,7 @@ public class Path implements IOReadableWritable, Serializable {
 
 	/**
 	 * Resolve a child path against a parent path.
-	 * 
+	 *
 	 * @param parent
 	 *        the parent path
 	 * @param child
@@ -105,7 +105,7 @@ public class Path implements IOReadableWritable, Serializable {
 
 	/**
 	 * Resolve a child path against a parent path.
-	 * 
+	 *
 	 * @param parent
 	 *        the parent path
 	 * @param child
@@ -117,7 +117,7 @@ public class Path implements IOReadableWritable, Serializable {
 
 	/**
 	 * Resolve a child path against a parent path.
-	 * 
+	 *
 	 * @param parent
 	 *        the parent path
 	 * @param child
@@ -168,7 +168,7 @@ public class Path implements IOReadableWritable, Serializable {
 	/**
 	 * Construct a path from a String. Path strings are URIs, but with unescaped
 	 * elements and some additional normalization.
-	 * 
+	 *
 	 * @param pathString
 	 *        the string to construct a path from
 	 */
@@ -214,7 +214,7 @@ public class Path implements IOReadableWritable, Serializable {
 
 	/**
 	 * Construct a Path from a scheme, an authority and a path string.
-	 * 
+	 *
 	 * @param scheme
 	 *        the scheme string
 	 * @param authority
@@ -229,7 +229,7 @@ public class Path implements IOReadableWritable, Serializable {
 
 	/**
 	 * Initializes a path object given the scheme, authority and path string.
-	 * 
+	 *
 	 * @param scheme
 	 *        the scheme string.
 	 * @param authority
@@ -247,7 +247,7 @@ public class Path implements IOReadableWritable, Serializable {
 
 	/**
 	 * Normalizes a path string.
-	 * 
+	 *
 	 * @param path
 	 *        the path string to normalize
 	 * @return the normalized path string
@@ -262,10 +262,10 @@ public class Path implements IOReadableWritable, Serializable {
 		path = path.replaceAll("/+", "/");
 
 		// remove tailing separator
-		if(!path.equals(SEPARATOR) &&         		// UNIX root path
+		if (!path.equals(SEPARATOR) &&              // UNIX root path
 				!path.matches("/\\p{Alpha}+:/") &&  // Windows root path
-				path.endsWith(SEPARATOR))
-		{
+				path.endsWith(SEPARATOR)) {
+
 			// remove tailing slash
 			path = path.substring(0, path.length() - SEPARATOR.length());
 		}
@@ -275,7 +275,7 @@ public class Path implements IOReadableWritable, Serializable {
 
 	/**
 	 * Converts the path object to a {@link URI}.
-	 * 
+	 *
 	 * @return the {@link URI} object converted from the path object
 	 */
 	public URI toUri() {
@@ -284,7 +284,7 @@ public class Path implements IOReadableWritable, Serializable {
 
 	/**
 	 * Returns the FileSystem that owns this Path.
-	 * 
+	 *
 	 * @return the FileSystem that owns this Path
 	 * @throws IOException
 	 *         thrown if the file system could not be retrieved
@@ -295,7 +295,7 @@ public class Path implements IOReadableWritable, Serializable {
 
 	/**
 	 * Checks if the directory of this path is absolute.
-	 * 
+	 *
 	 * @return <code>true</code> if the directory of this path is absolute, <code>false</code> otherwise
 	 */
 	public boolean isAbsolute() {
@@ -305,7 +305,7 @@ public class Path implements IOReadableWritable, Serializable {
 
 	/**
 	 * Returns the final component of this path, i.e., everything that follows the last separator.
-	 * 
+	 *
 	 * @return the final component of the path
 	 */
 	public String getName() {
@@ -325,7 +325,7 @@ public class Path implements IOReadableWritable, Serializable {
 	/**
 	 * Returns the parent of a path, i.e., everything that precedes the last separator
 	 * or <code>null</code> if at root.
-	 * 
+	 *
 	 * @return the parent of a path or <code>null</code> if at root.
 	 */
 	public Path getParent() {
@@ -348,7 +348,7 @@ public class Path implements IOReadableWritable, Serializable {
 
 	/**
 	 * Adds a suffix to the final name in the path.
-	 * 
+	 *
 	 * @param suffix The suffix to be added
 	 * @return the new path including the suffix
 	 */
@@ -381,7 +381,6 @@ public class Path implements IOReadableWritable, Serializable {
 		return buffer.toString();
 	}
 
-
 	@Override
 	public boolean equals(Object o) {
 		if (!(o instanceof Path)) {
@@ -391,7 +390,6 @@ public class Path implements IOReadableWritable, Serializable {
 		return this.uri.equals(that.uri);
 	}
 
-
 	@Override
 	public int hashCode() {
 		return uri.hashCode();
@@ -404,7 +402,7 @@ public class Path implements IOReadableWritable, Serializable {
 
 	/**
 	 * Returns the number of elements in this path.
-	 * 
+	 *
 	 * @return the number of elements in this path
 	 */
 	public int depth() {
@@ -420,7 +418,7 @@ public class Path implements IOReadableWritable, Serializable {
 
 	/**
 	 * Returns a qualified path object.
-	 * 
+	 *
 	 * @param fs
 	 *        the FileSystem that should be used to obtain the current working directory
 	 * @return the qualified path object
@@ -479,7 +477,6 @@ public class Path implements IOReadableWritable, Serializable {
 		}
 	}
 
-
 	@Override
 	public void write(DataOutputView out) throws IOException {
 		if (uri == null) {
@@ -516,7 +513,7 @@ public class Path implements IOReadableWritable, Serializable {
 	 *        the path to check
 	 * @param slashed
 	 *         true to indicate the first character of the string is a slash, false otherwise
-	 * 
+	 *
 	 * @return <code>true</code> if the path string contains a windows drive letter, false otherwise
 	 */
 	private boolean hasWindowsDrive(String path, boolean slashed) {

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

@@ -20,11 +20,9 @@ package org.apache.flink.core.fs;
 
 import org.apache.flink.annotation.Internal;
 import org.apache.flink.configuration.Configuration;
-import org.apache.flink.core.fs.FileSystem;
-import org.apache.flink.core.fs.FileSystemFactory;
-import org.apache.flink.core.fs.UnsupportedFileSystemSchemeException;
 
 import javax.annotation.Nullable;
+
 import java.io.IOException;
 import java.net.URI;
 

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

@@ -27,6 +27,4 @@ import java.io.Closeable;
  * {@link WrappingProxy} for {@link Closeable} that is also closeable.
  */
 @Internal
-public interface WrappingProxyCloseable<T extends Closeable> extends Closeable, WrappingProxy<T> {
-
-}
+public interface WrappingProxyCloseable<T extends Closeable> extends Closeable, WrappingProxy<T> {}