[hotfix] [core] Minor code cleanups in 'LocalFileSystem'.

This makes members final where possible and avoids repeated access to the system properties.
This commit also brings the formatting style closer to the style of the other Flink classes.

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

@@ -16,7 +16,6 @@
  * limitations under the License.
  */
 
-
 package org.apache.flink.core.fs.local;
 
 import java.io.IOException;
@@ -25,9 +24,7 @@
 import org.apache.flink.core.fs.BlockLocation;
 
 /**
- * Implementation of the {@link BlockLocation} interface for a
- * local file system.
- * 
+ * Implementation of the {@link BlockLocation} interface for a local file system.
  */
 @Internal
 public class LocalBlockLocation implements BlockLocation {
@@ -41,30 +38,23 @@ public LocalBlockLocation(final String host, final long length) {
  this.length = length;
  }
 
-
  @Override
  public String[] getHosts() throws IOException {
-
  return this.hosts;
  }
 
-
  @Override
  public long getLength() {
-
  return this.length;
  }
 
-
  @Override
  public long getOffset() {
  return 0;
  }
 
-
  @Override
  public int compareTo(final BlockLocation o) {
  return 0;
  }
-
 }

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

@@ -29,7 +29,6 @@
 /**
  * The class <code>LocalFileStatus</code> provides an implementation of the {@link FileStatus} interface
  * for the local file system.
- * 
  */
 @Internal
 public class LocalFileStatus implements FileStatus {
@@ -57,48 +56,41 @@ public LocalFileStatus(final File f, final FileSystem fs) {
  this.path = new Path(fs.getUri().getScheme() + ":" + f.toURI().getPath());
  }
 
-
  @Override
  public long getAccessTime() {
  return 0; // We don't have access files for local files
  }
 
-
  @Override
  public long getBlockSize() {
  return this.file.length();
  }
 
-
  @Override
  public long getLen() {
  return this.file.length();
  }
 
-
  @Override
  public long getModificationTime() {
  return this.file.lastModified();
  }
 
-
  @Override
  public short getReplication() {
  return 1; // For local files replication is always 1
  }
 
-
  @Override
  public boolean isDir() {
  return this.file.isDirectory();
  }
 
-
  @Override
  public Path getPath() {
  return this.path;
  }
- 
+
  public File getFile() {
  return this.file;
  }

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

@@ -25,16 +25,7 @@
 
 package org.apache.flink.core.fs.local;
 
-import java.io.File;
-import java.io.FileNotFoundException;
-import java.io.IOException;
-import java.net.InetAddress;
-import java.net.URI;
-import java.net.UnknownHostException;
-
 import org.apache.flink.annotation.Internal;
-import org.slf4j.Logger;
-import org.slf4j.LoggerFactory;
 import org.apache.flink.core.fs.BlockLocation;
 import org.apache.flink.core.fs.FSDataInputStream;
 import org.apache.flink.core.fs.FSDataOutputStream;
@@ -43,63 +34,66 @@
 import org.apache.flink.core.fs.Path;
 import org.apache.flink.util.OperatingSystem;
 
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import java.io.File;
+import java.io.FileNotFoundException;
+import java.io.IOException;
+import java.net.InetAddress;
+import java.net.URI;
+import java.net.UnknownHostException;
+
 /**
- * The class <code>LocalFile</code> provides an implementation of the {@link FileSystem} interface for the local file
- * system.
- * 
+ * The class <code>LocalFile</code> provides an implementation of the {@link FileSystem} interface
+ * for the local file system of the machine where the JVM runs.
  */
 @Internal
 public class LocalFileSystem extends FileSystem {
 
- /**
- * Path pointing to the current working directory.
- */
- private Path workingDir = null;
+ private static final Logger LOG = LoggerFactory.getLogger(LocalFileSystem.class);
 
- /**
- * The URI representing the local file system.
- */
- private final URI name = OperatingSystem.isWindows() ? URI.create("file:/") : URI.create("file:///");
+ /** The URI representing the local file system. */
+ private static final URI uri = OperatingSystem.isWindows() ? URI.create("file:/") : URI.create("file:///");
 
- /**
- * The host name of this machine;
- */
- private final String hostName;
+ /** Path pointing to the current working directory.
+ * Because Paths are not immutable, we cannot cache the proper path here */
+ private final String workingDir;
 
- private static final Logger LOG = LoggerFactory.getLogger(LocalFileSystem.class);
+ /** Path pointing to the current working directory.
+ * Because Paths are not immutable, we cannot cache the proper path here */
+ private final String homeDir;
+
+ /** The host name of this machine */
+ private final String hostName;
 
  /**
  * Constructs a new <code>LocalFileSystem</code> object.
  */
  public LocalFileSystem() {
- this.workingDir = new Path(System.getProperty("user.dir")).makeQualified(this);
+ this.workingDir = new Path(System.getProperty("user.dir")).makeQualified(this).toString();
+ this.homeDir = new Path(System.getProperty("user.home")).toString();
 
  String tmp = "unknownHost";
-
  try {
  tmp = InetAddress.getLocalHost().getHostName();
  } catch (UnknownHostException e) {
  LOG.error("Could not resolve local host", e);
  }
-
  this.hostName = tmp;
  }
 
+ // ------------------------------------------------------------------------
 
  @Override
- public BlockLocation[] getFileBlockLocations(final FileStatus file, final long start, final long len)
- throws IOException {
-
- final BlockLocation[] blockLocations = new BlockLocation[1];
- blockLocations[0] = new LocalBlockLocation(this.hostName, file.getLen());
-
- return blockLocations;
+ public BlockLocation[] getFileBlockLocations(FileStatus file, long start, long len) throws IOException {
+ return new BlockLocation[] {
+ new LocalBlockLocation(hostName, file.getLen())
+ };
  }
 
-
  @Override
  public FileStatus getFileStatus(Path f) throws IOException {
-
  final File path = pathToFile(f);
  if (path.exists()) {
  return new LocalFileStatus(pathToFile(f), this);
@@ -110,40 +104,35 @@ public FileStatus getFileStatus(Path f) throws IOException {
  }
  }
 
-
  @Override
  public URI getUri() {
- return name;
+ return uri;
  }
 
-
  @Override
  public Path getWorkingDirectory() {
- return workingDir;
+ return new Path(workingDir);
  }
 
  @Override
  public Path getHomeDirectory() {
- return new Path(System.getProperty("user.home"));
+ return new Path(homeDir);
  }
 
  @Override
- public void initialize(final URI name) throws IOException { }
-
+ public void initialize(final URI name) throws IOException {}
 
  @Override
  public FSDataInputStream open(final Path f, final int bufferSize) throws IOException {
  return open(f);
  }
 
-
  @Override
  public FSDataInputStream open(final Path f) throws IOException {
  final File file = pathToFile(f);
  return new LocalDataInputStream(file);
  }
 
-
  private File pathToFile(Path path) {
  if (!path.isAbsolute()) {
  path = new Path(getWorkingDirectory(), path);
@@ -208,15 +197,13 @@ public boolean delete(final Path f, final boolean recursive) throws IOException
  private boolean delete(final File f) throws IOException {
 
  if (f.isDirectory()) {
-
  final File[] files = f.listFiles();
  for (File file : files) {
  final boolean del = delete(file);
  if (!del) {
  return false;
  }
  }
-
  } else {
  return f.delete();
  }
@@ -234,7 +221,6 @@ private boolean delete(final File f) throws IOException {
  * thrown if an error occurred while creating the directory/directories
  */
  public boolean mkdirs(final Path f) throws IOException {
-
  final File p2f = pathToFile(f);
 
  if(p2f.isDirectory()) {
@@ -266,14 +252,12 @@ public FSDataOutputStream create(final Path f, final boolean overwrite, final in
 
  @Override
  public FSDataOutputStream create(final Path f, final boolean overwrite) throws IOException {
-
  return create(f, overwrite, 0, (short) 0, 0);
  }
 
 
  @Override
  public boolean rename(final Path src, final Path dst) throws IOException {
-
  final File srcFile = pathToFile(src);
  final File dstFile = pathToFile(dst);