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Diffstat (limited to 'libjava/classpath/java/lang/annotation/Annotation.java')
-rw-r--r-- | libjava/classpath/java/lang/annotation/Annotation.java | 136 |
1 files changed, 136 insertions, 0 deletions
diff --git a/libjava/classpath/java/lang/annotation/Annotation.java b/libjava/classpath/java/lang/annotation/Annotation.java new file mode 100644 index 00000000000..01e23930eea --- /dev/null +++ b/libjava/classpath/java/lang/annotation/Annotation.java @@ -0,0 +1,136 @@ +/* Annotation.java - Base interface for all annotations + Copyright (C) 2004 Free Software Foundation + +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., 51 Franklin Street, Fifth Floor, Boston, MA +02110-1301 USA. + +Linking this library statically or dynamically with other modules is +making a combined work based on this library. Thus, the terms and +conditions of the GNU General Public License cover the whole +combination. + +As a special exception, the copyright holders of this library give you +permission to link this library with independent modules to produce an +executable, regardless of the license terms of these independent +modules, and to copy and distribute the resulting executable under +terms of your choice, provided that you also meet, for each linked +independent module, the terms and conditions of the license of that +module. An independent module is a module which is not derived from +or based on this library. If you modify this library, you may extend +this exception to your version of the library, but you are not +obligated to do so. If you do not wish to do so, delete this +exception statement from your version. */ + +package java.lang.annotation; + +/** + * This is the common interface for all annotations. Note that classes + * that implement this class manually are not classed as annotations, and + * that this interface does not define an annotation type in itself. + * + * @author Tom Tromey (tromey@redhat.com) + * @author Andrew John Hughes (gnu_andrew@member.fsf.org) + * @since 1.5 + */ +public interface Annotation +{ + + /** + * Returns the type of this annotation. + * + * @return the class of which this annotation is an instance. + */ + /* FIXME[GENERICS]: Should return Class<? extends Annotation> */ + Class annotationType(); + + /** + * <p> + * Returns true if the supplied object is equivalent to this annotation. + * For this property to hold, the following must be true of <code>o</code>: + * </p> + * <ul> + * <li>The object is also an instance of the same annotation type.</li> + * <li>The members of the supplied annotation are equal to those of this + * annotation, according to the following: + * <ul> + * <li>If the members are <code>float</code>s, then, for floats + * <code>x</code> and <code>y</code>, + * <code>Float.valueOf(x).equals(Float.valueOf(y)</code> must return + * true. This differs from the usual (<code>==</code>) comparison + * in that <code>NaN</code> is considered equal to itself and positive + * and negative zero are seen as different.</li> + * <li>Likewise, if the members are <code>double</code>s, then, for doubles + * <code>x</code> and <code>y</code>, + * <code>Double.valueOf(x).equals(Double.valueOf(y)</code> must return + * true. This differs from the usual (<code>==</code>) comparison + * in that <code>NaN</code> is considered equal to itself and positive + * and negative zero are seen as different.</li> + * <li>Strings, classes, enumerations and annotations are considered + * equal according to the <code>equals()</code> implementation for these + * types.</li> + * <li>Arrays are considered equal according to <code>Arrays.equals()</code> + * </li> + * <li>Any remaining types are considered equal using <code>==</code>.</li> + * </li> + * </ul> + * + * @param o the object to compare with this annotation. + * @return true if the supplied object is an annotation with equivalent + * members. + */ + boolean equals(Object o); + + /** + * <p> + * Returns the hash code of the annotation. This is computed as the + * sum of the hash codes of the annotation's members. + * </p> + * <p> + * The hash code of a member of the annotation is the result of XORing + * the hash code of its value with the result of multiplying the hash code + * of its name by 127. Formally, if the value is <code>v</code> and the + * name is <code>n</code>, the hash code of the member is + * v.hashCode() XOR (127 * String.hashCode(n)). <code>v.hashCode()</code> + * is defined as follows: + * </p> + * <ul> + * <li>The hash code of a primitive value (i.e. <code>byte</code>, + * <code>char</code>, <code>double</code>, <code>float</code>, + * <code>int</code>, <code>long</code>, <code>short</code> and + * <code>boolean</code>) is the hash code obtained from its corresponding + * wrapper class using <code>valueOf(v).hashCode()</code>, where + * <code>v</code> is the primitive value.</li> + * <li>The hash code of an enumeration, string, class or other annotation + * is obtained using <code>v.hashCode()</code>.</li> + * <li>The hash code of an array is computed using + * <code>Arrays.hashCode(v)</code>.</li> + * </ul> + * + * @return the hash code of the annotation, computed as the sum of its + * member hashcodes. + */ + int hashCode(); + + /** + * Returns a textual representation of the annotation. This is + * implementation-dependent, but is expected to include the classname + * and the names and values of each member. + * + * @return a textual representation of the annotation. + */ + String toString(); +} |