Lucene example source code file (IOUtils.java)

This example Lucene source code file (IOUtils.java) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" ^TM.

Java - Lucene tags/keywords

closeable, e, error, error, exception, io, ioexception, ioexception, ioutils, iterable, runtimeexception, runtimeexception, throwable, throwable

The Lucene IOUtils.java source code

package org.apache.lucene.util;

/**
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

import java.io.Closeable;
import java.io.IOException;

/** @lucene.internal */
public final class IOUtils {

  private IOUtils() {} // no instance

  /**
   * <p>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 <tt>priorException,
   * if one is supplied, or the first of suppressed exceptions, or completes normally.</p>
   * <p>Sample usage:

   * <pre>
   * 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 {
   *   closeSafely(priorE, resource1, resource2, resource3);
   * }
   * </pre>
   * </p>
   * @param priorException  <tt>null or an exception that will be rethrown after method completion
   * @param objects         objects to call <tt>close() on
   */
  public static <E extends Exception> void closeSafely(E priorException, Closeable... objects) throws E, IOException {
    Throwable th = null;

    for (Closeable object : objects) {
      try {
        if (object != null) {
          object.close();
        }
      } catch (Throwable t) {
        if (th == null) {
          th = t;
        }
      }
    }

    if (priorException != null) {
      throw priorException;
    } else if (th != null) {
      if (th instanceof IOException) throw (IOException) th;
      if (th instanceof RuntimeException) throw (RuntimeException) th;
      if (th instanceof Error) throw (Error) th;
      throw new RuntimeException(th);
    }
  }

  /** @see #closeSafely(Exception, Closeable...) */
  public static <E extends Exception> void closeSafely(E priorException, Iterable objects) throws E, IOException {
    Throwable th = null;

    for (Closeable object : objects) {
      try {
        if (object != null) {
          object.close();
        }
      } catch (Throwable t) {
        if (th == null) {
          th = t;
        }
      }
    }

    if (priorException != null) {
      throw priorException;
    } else if (th != null) {
      if (th instanceof IOException) throw (IOException) th;
      if (th instanceof RuntimeException) throw (RuntimeException) th;
      if (th instanceof Error) throw (Error) th;
      throw new RuntimeException(th);
    }
  }

  /**
   * Closes all given <tt>Closeables, suppressing all thrown exceptions.
   * Some of the <tt>Closeables may be null, they are ignored. After
   * everything is closed, and if {@code suppressExceptions} is {@code false},
   * method either throws the first of suppressed exceptions, or completes
   * normally.
   * 
   * @param suppressExceptions
   *          if true then exceptions that occur during close() are suppressed
   * @param objects
   *          objects to call <tt>close() on
   */
  public static void closeSafely(boolean suppressExceptions, Closeable... objects) throws IOException {
    Throwable th = null;

    for (Closeable object : objects) {
      try {
        if (object != null) {
          object.close();
        }
      } catch (Throwable t) {
        if (th == null)
          th = t;
      }
    }

    if (th != null && !suppressExceptions) {
      if (th instanceof IOException) throw (IOException) th;
      if (th instanceof RuntimeException) throw (RuntimeException) th;
      if (th instanceof Error) throw (Error) th;
      throw new RuntimeException(th);
    }
  }
  
  /**
   * @see #closeSafely(boolean, Closeable...)
   */
  public static void closeSafely(boolean suppressExceptions, Iterable<? extends Closeable> objects) throws IOException {
    Throwable th = null;

    for (Closeable object : objects) {
      try {
        if (object != null) {
          object.close();
        }
      } catch (Throwable t) {
        if (th == null)
          th = t;
      }
    }

    if (th != null && !suppressExceptions) {
      if (th instanceof IOException) throw (IOException) th;
      if (th instanceof RuntimeException) throw (RuntimeException) th;
      if (th instanceof Error) throw (Error) th;
      throw new RuntimeException(th);
    }
  }

}