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author | Anthony Green <green@redhat.com> | 2000-08-19 18:19:42 +0000 |
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committer | Anthony Green <green@gcc.gnu.org> | 2000-08-19 18:19:42 +0000 |
commit | a729a4e9aba7afb312ee0f15a70979ae75d1a9fe (patch) | |
tree | 2dff323eee68e61f9225ea0c6c7f15f7c6bcd624 /libjava/java/util/AbstractSet.java | |
parent | e76d9acbe9055e6f0ec35f4e5d0893ca10baf643 (diff) | |
download | gcc-a729a4e9aba7afb312ee0f15a70979ae75d1a9fe.zip gcc-a729a4e9aba7afb312ee0f15a70979ae75d1a9fe.tar.gz gcc-a729a4e9aba7afb312ee0f15a70979ae75d1a9fe.tar.bz2 |
Attributes.java, [...]: Imported from Classpath.
Sat Aug 19 11:00:53 2000 Anthony Green <green@redhat.com>
* java/util/jar/Attributes.java, java/util/jar/JarEntry.java,
java/util/jar/JarException.java, java/util/jar/JarFile.java,
java/util/jar/JarInputStream.java,
java/util/jar/JarOutputStream.java, java/util/jar/Manifest.java,
java/util/Set.java, java/util/Map.java, java/util/Bucket.java,
java/util/AbstractSet.java, java/util/BasicMapEntry.java,
java/security/cert/CRL.java, java/security/cert/CRLException.java,
java/security/cert/Certificate.java,
java/security/cert/CertificateEncodingException.java,
java/security/cert/CertificateException.java,
java/security/cert/CertificateExpiredException.java,
java/security/cert/CertificateFactory.java,
java/security/cert/CertificateFactorySpi.java,
java/security/cert/CertificateNotYetValidException.java,
java/security/cert/CertificateParsingException.java,
java/security/cert/X509CRL.java,
java/security/cert/X509CRLEntry.java,
java/security/cert/X509Certificate.java,
java/security/cert/X509Extension.java: Imported from Classpath.
* java/util/Hashtable.java: Imported from Classpath.
* java/util/zip/ZipInputStream.java: Create stub for
createZipEntry.
* gcj/javaprims.h: Updated class list.
* Makefile.in, gcj/Makefile.in: Rebuilt.
* Makefile.am (ordinary_java_source_files): Add these new classes.
From-SVN: r35809
Diffstat (limited to 'libjava/java/util/AbstractSet.java')
-rw-r--r-- | libjava/java/util/AbstractSet.java | 83 |
1 files changed, 83 insertions, 0 deletions
diff --git a/libjava/java/util/AbstractSet.java b/libjava/java/util/AbstractSet.java new file mode 100644 index 0000000..b2dd30b --- /dev/null +++ b/libjava/java/util/AbstractSet.java @@ -0,0 +1,83 @@ +/* AbstractSet.java -- Abstract implementation of most of Set + Copyright (C) 1998 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 java.util; + +/** + * An abstract implementation of Set to make it easier to create your own + * implementations. In order to create a Set, subclass AbstractSet and + * implement the same methods that are required for AbstractCollection + * (although these methods must of course meet the requirements that Set puts + * on them - specifically, no element may be in the set more than once). This + * class simply provides implementations of equals() and hashCode() to fulfil + * the requirements placed on them by the Set interface. + */ +public abstract class AbstractSet extends AbstractCollection implements Set { + + /** + * Tests whether the given object is equal to this Set. This implementation + * first checks whether this set <em>is</em> the given object, and returns + * true if so. Otherwise, if o is a Set and is the same size as this one, it + * returns the result of calling containsAll on the given Set. Otherwise, it + * returns false. + * + * @param o the Object to be tested for equality with this Set + * @return true if the given object is equal to this Set + */ + public boolean equals(Object o) { + if (o == this) { + return true; + } else if (o instanceof Set && ((Set)o).size() == size()) { + throw new Error ("FIXME: compiler error - AbstractSet.equals"); + /* FIXME: this is the correct implementation, but a compiler + error prevents us from building it. + return containsAll((Collection)o); */ + } else { + return false; + } + } + + /** + * Returns a hash code for this Set. The hash code of a Set is the sum of the + * hash codes of all its elements, except that the hash code of null is + * defined to be zero. This implementation obtains an Iterator over the Set, + * and sums the results. + * + * @return a hash code for this Set + */ + public int hashCode() { + int hash = 0; + Iterator i = iterator(); + while (i.hasNext()) { + try { + hash += i.next().hashCode(); + } catch (NullPointerException e) { + } + } + return hash; + } +} |