Package org.apache.lucene.util

Class IOUtils

java.lang.Object
org.apache.lucene.util.IOUtils
public final class IOUtils extends Object
This class emulates the new Java 7 "Try-With-Resources" statement. Remove once Lucene is on Java 7.

  • Field Details

  • Method Details

    • closeWhileHandlingException

      public static <E extends Exception> void closeWhileHandlingException(E priorException, Closeable... objects) throws E, IOException

      Closes all given Closeables, suppressing all thrown exceptions. Some of the Closeables may be null, they are ignored. After everything is closed, method either throws priorException, if one is supplied, or the first of suppressed exceptions, or completes normally.

      Sample usage:

       Closeable resource1 = null, resource2 = null, resource3 = null;
 ExpectedException priorE = null;
 try {
   resource1 = ...; resource2 = ...; resource3 = ...; // Acquisition may throw ExpectedException
   ..do..stuff.. // May throw ExpectedException
 } catch (ExpectedException e) {
   priorE = e;
 } finally {
   closeWhileHandlingException(priorE, resource1, resource2, resource3);
 }

      Parameters:
      priorException - null or an exception that will be rethrown after method completion
      objects - objects to call close() on
      Throws:
      E
      IOException

    • closeWhileHandlingException

      public static <E extends Exception> void closeWhileHandlingException(E priorException, Iterable<? extends Closeable> objects) throws E, IOException
      Closes all given Closeables, suppressing all thrown exceptions.
      Throws:
      E
      IOException
      See Also:

    • close

      public static void close(Closeable... objects) throws IOException
      Closes all given Closeables. Some of the Closeables may be null; they are ignored. After everything is closed, the method either throws the first exception it hit while closing, or completes normally if there were no exceptions.
      Parameters:
      objects - objects to call close() on
      Throws:
      IOException

    • close

      public static void close(Iterable<? extends Closeable> objects) throws IOException
      Closes all given Closeables.
      Throws:
      IOException
      See Also:

    • closeWhileHandlingException

      public static void closeWhileHandlingException(Closeable... objects)
      Closes all given Closeables, suppressing all thrown exceptions. Some of the Closeables may be null, they are ignored.
      Parameters:
      objects - objects to call close() on

    • closeWhileHandlingException

      public static void closeWhileHandlingException(Iterable<? extends Closeable> objects)
      Closes all given Closeables, suppressing all thrown exceptions.
      See Also:

    • getDecodingReader

      public static Reader getDecodingReader(InputStream stream, Charset charSet)
      Wrapping the given InputStream in a reader using a CharsetDecoder. Unlike Java's defaults this reader will throw an exception if your it detects the read charset doesn't match the expected Charset.

      Decoding readers are useful to load configuration files, stopword lists or synonym files to detect character set problems. However, its not recommended to use as a common purpose reader.

      Parameters:
      stream - the stream to wrap in a reader
      charSet - the expected charset
      Returns:
      a wrapping reader

    • getDecodingReader

      public static Reader getDecodingReader(File file, Charset charSet) throws IOException
      Opens a Reader for the given File using a CharsetDecoder. Unlike Java's defaults this reader will throw an exception if your it detects the read charset doesn't match the expected Charset.

      Decoding readers are useful to load configuration files, stopword lists or synonym files to detect character set problems. However, its not recommended to use as a common purpose reader.

      Parameters:
      file - the file to open a reader on
      charSet - the expected charset
      Returns:
      a reader to read the given file
      Throws:
      IOException

    • getDecodingReader

      public static Reader getDecodingReader(Class<?> clazz, String resource, Charset charSet) throws IOException
      Opens a Reader for the given resource using a CharsetDecoder. Unlike Java's defaults this reader will throw an exception if your it detects the read charset doesn't match the expected Charset.

      Decoding readers are useful to load configuration files, stopword lists or synonym files to detect character set problems. However, its not recommended to use as a common purpose reader.

      Parameters:
      clazz - the class used to locate the resource
      resource - the resource name to load
      charSet - the expected charset
      Returns:
      a reader to read the given file
      Throws:
      IOException

    • deleteFilesIgnoringExceptions

      public static void deleteFilesIgnoringExceptions(Directory dir, String... files)
      Deletes all given files, suppressing all thrown IOExceptions.

      Note that the files should not be null.

    • copy

      public static void copy(File source, File target) throws IOException
      Copy one file's contents to another file. The target will be overwritten if it exists. The source must exist.
      Throws:
      IOException

    • reThrow

      public static void reThrow(Throwable th) throws IOException
      Simple utilty method that takes a previously caught Throwable and rethrows either IOException or an unchecked exception. If the argument is null then this method does nothing.
      Throws:
      IOException

    • reThrowUnchecked

      public static void reThrowUnchecked(Throwable th)
      Simple utilty method that takes a previously caught Throwable and rethrows it as an unchecked exception. If the argument is null then this method does nothing.