org.apache.mahout.common

Class IOUtils

java.lang.Object

org.apache.mahout.common.IOUtils

public final class IOUtils
extends Object

I/O-related utility methods that don't have a better home.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	IOUtils.DeleteFileOnClose for temporary files, a file may be considered as a Closeable too, where file is wiped on close and thus the disk resource is released ('closed').
static class	IOUtils.MultipleOutputsCloseableAdapter MultipleOutputs to closeable adapter.

Method Summary

Methods

Modifier and Type	Method and Description
static void	close(Collection<? extends Closeable> closeables) make sure to close all sources, log all of the problems occurred, clear closeables (to prevent repeating close attempts), re-throw the last one at the end.
static void	quietClose(Connection closeable)
static void	quietClose(ResultSet closeable)
static void	quietClose(ResultSet resultSet, Statement statement, Connection connection) Closes a ResultSet, Statement and Connection (if not null) and logs (but does not rethrow) any resulting SQLException.
static void	quietClose(Statement closeable)

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Method Detail

quietClose

public static void quietClose(ResultSet closeable)

quietClose

public static void quietClose(Statement closeable)

quietClose

public static void quietClose(Connection closeable)

quietClose

public static void quietClose(ResultSet resultSet,
              Statement statement,
              Connection connection)

Closes a ResultSet, Statement and Connection (if not null) and logs (but does not rethrow) any resulting SQLException. This is useful for cleaning up after a database query.

Parameters:

resultSet - ResultSet to close

statement - Statement to close

connection - Connection to close

close

public static void close(Collection<? extends Closeable> closeables)
                  throws IOException

make sure to close all sources, log all of the problems occurred, clear closeables (to prevent repeating close attempts), re-throw the last one at the end. Helps resource scope management (e.g. compositions of Closeables objects)

Typical pattern:

   LinkedList closeables = new LinkedList();
   try {
      InputStream stream1 = new FileInputStream(...);
      closeables.addFirst(stream1);
      ...
      InputStream streamN = new FileInputStream(...);
      closeables.addFirst(streamN);
      ...
   } finally {
      IOUtils.close(closeables);
   }
 

Parameters:

closeables - must be a modifiable collection of Closeables

Throws:

IOException - the last exception (if any) of all closed resources