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author | Tom Tromey <tromey@redhat.com> | 2001-08-31 21:31:20 +0000 |
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committer | Tom Tromey <tromey@gcc.gnu.org> | 2001-08-31 21:31:20 +0000 |
commit | 7a95ae6b51b590a8b8b9ee06768204c5d6a4a90f (patch) | |
tree | 57cf10eba5f71e6072958cb8ef14beb8842f8b91 /libjava/gnu/java | |
parent | fb9282f91f0bc4f90f30cd6fa5a18c91f0e7e32a (diff) | |
download | gcc-7a95ae6b51b590a8b8b9ee06768204c5d6a4a90f.zip gcc-7a95ae6b51b590a8b8b9ee06768204c5d6a4a90f.tar.gz gcc-7a95ae6b51b590a8b8b9ee06768204c5d6a4a90f.tar.bz2 |
Makefile.in: Rebuilt.
* Makefile.in: Rebuilt.
* Makefile.am (ordinary_java_source_files): Removed
EnumerationChain, added DoubleEnumeration.
(nat_source_files): Added natResourceBundle.cc.
* java/util/natResourceBundle.cc: New file.
* gnu/java/util/DoubleEnumeration.java: New file.
* gnu/gcj/util/EnumerationChain.java: Removed.
* java/beans/VetoableChangeSupport.java: Merged with Classpath.
* java/util/ResourceBundle.java: Merged with Classpath.
* java/util/StringTokenizer.java: Merged with Classpath.
* java/util/Locale.java: Merged with Classpath.
* java/util/Random.java: Merged with Classpath.
* java/util/PropertyResourceBundle.java: Merged with Classpath.
* java/util/ListResourceBundle.java: Merged with Classpath.
* java/util/ConcurrentModificationException.java: Re-merged with
Classpath.
* java/util/EmptyStackException.java: Likewise.
* java/util/MissingResourceException.java: Likewise.
* java/util/NoSuchElementException.java: Likewise.
* java/util/TooManyListenersException.java: Likewise.
From-SVN: r45335
Diffstat (limited to 'libjava/gnu/java')
-rw-r--r-- | libjava/gnu/java/util/DoubleEnumeration.java | 128 |
1 files changed, 128 insertions, 0 deletions
diff --git a/libjava/gnu/java/util/DoubleEnumeration.java b/libjava/gnu/java/util/DoubleEnumeration.java new file mode 100644 index 0000000..33aa2d8 --- /dev/null +++ b/libjava/gnu/java/util/DoubleEnumeration.java @@ -0,0 +1,128 @@ +/* gnu.java.util.DoubleEnumeration + Copyright (C) 1998, 1999, 2001 Free Software Foundation, Inc. + +This file is part of GNU Classpath. + +GNU Classpath is free software; you can redistribute it and/or modify +it under the terms of the GNU General Public License as published by +the Free Software Foundation; either version 2, or (at your option) +any later version. + +GNU Classpath is distributed in the hope that it will be useful, but +WITHOUT ANY WARRANTY; without even the implied warranty of +MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU +General Public License for more details. + +You should have received a copy of the GNU General Public License +along with GNU Classpath; see the file COPYING. If not, write to the +Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA +02111-1307 USA. + +As a special exception, if you link this library with other files to +produce an executable, this library does not by itself cause the +resulting executable to be covered by the GNU General Public License. +This exception does not however invalidate any other reasons why the +executable file might be covered by the GNU General Public License. */ + +package gnu.java.util; + +import java.io.*; +import java.util.Enumeration; +import java.util.NoSuchElementException; + + +/** + * This is a helper class that combines two Enumerations. + * It returns the elements of the first Enumeration until it has + * no more elements and then returns the elements of the second + * Enumeration.<br> + * + * In the default case: + * <pre> + * doubleEnum = new DoubleEnumeration(enum1, enum2); + * while (doubleEnum.hasMoreElements()) { + * Object o = doubleEnum.nextElement(); + * do_something(o); + * } + * </pre> + * it calls hasMoreElements of the Enumerations as few times as + * possible. + * The references to the Enumerations are cleared as soon as they have no + * more elements to help garbage collecting. + * + * @author Jochen Hoenicke + * @author Mark Wielaard (mark@klomp.org) + */ +public class DoubleEnumeration implements Enumeration +{ + /** + * This is true as long as one of the enumerations has more + * elements. + * Only valid when hasChecked is true. + * Set in <code>hasMoreElements()</code> + */ + private boolean hasMore; + /** + * This is true, if it is sure that hasMore indicates wether there are + * more elements. + * Set to true in <code>hasMoreElements()</code>. + * Set to false in <code>getNextElement()</code>. + */ + private boolean hasChecked; + /** + * The first enumeration. + */ + private Enumeration e1; + /** + * The second enumeration. + */ + private Enumeration e2; + + /** + * Creates a new Enumeration combining the given two enumerations. + * The enumerations mustn't be accessed by other classes. + */ + public DoubleEnumeration(Enumeration e1, Enumeration e2) + { + this.e1 = e1; + this.e2 = e2; + hasChecked = false; + } + + /** + * Returns true, if at least one of the two enumerations has more + * elements. + */ + public boolean hasMoreElements() + { + if (hasChecked) + return hasMore; + + hasMore = (e1 != null && e1.hasMoreElements()); + + if (!hasMore) { + e1 = e2; + e2 = null; + hasMore = (e1 != null && e1.hasMoreElements()); + } + + hasChecked = true; + return hasMore; + } + + /** + * Returns the next element. This returns the next element of the + * first enumeration, if it has more elements, otherwise the next + * element of the second enumeration. If both enumeration don't have + * any elements it throws a <code>NoSuchElementException</code>. + */ + public Object nextElement() + { + if (!hasMoreElements()) + throw new NoSuchElementException(); + else { + hasChecked = false; + return e1.nextElement(); + } + } +} |