MapReduce - Hadoop: The Definitive Guide - page 75

encapsulates filesystem metadata for files and directories, including file length, block size,
replication, modification time, ownership, and permission information.
The method getFileStatus() on FileSystem provides a way of getting a
FileStatus object for a single file or directory. Example 3-5 shows an example of its
use.
Example 3-5. Demonstrating file status information
public class ShowFileStatusTest {
private MiniDFSCluster cluster ; // use an in-process HDFS cluster for
testing
private FileSystem fs ;
@Before
public void setUp () throws IOException {
Configuration conf = new Configuration ();
if ( System . getProperty ( "test.build.data" ) == null ) {
System . setProperty ( "test.build.data" , "/tmp" );
}
cluster = new MiniDFSCluster . Builder ( conf ). build ();
fs = cluster . getFileSystem ();
OutputStream out = fs . create ( new Path ( "/dir/file" ));
out . write ( "content" . getBytes ( "UTF-8" ));
out . close ();
}
@After
public void tearDown () throws IOException {
if ( fs != null ) { fs . close (); }
if ( cluster != null ) { cluster . shutdown (); }
}
@Test ( expected = FileNotFoundException . class )
public void throwsFileNotFoundForNonExistentFile () throws IOException
{
fs . getFileStatus ( new Path ( "no-such-file" ));
}
@Test
public void fileStatusForFile () throws IOException {
Path file = new Path ( "/dir/file" );
FileStatus stat = fs . getFileStatus ( file );
assertThat ( stat . getPath (). toUri (). getPath (), is ( "/dir/file" ));
assertThat ( stat . isDirectory (), is ( false ));
assertThat ( stat . getLen (), is ( 7L ));