java.lang.annotation

Interface Annotation

public interface 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.
Since:
1.5

Method Summary

boolean
equals(Object o)
Returns true if the supplied object is equivalent to this annotation.
Class
extends Annotation> annotationType()
Returns the type of this annotation.
int
hashCode()
Returns the hash code of the annotation.
String
toString()
Returns a textual representation of the annotation.

Method Details

equals

public boolean equals(Object o)
Returns true if the supplied object is equivalent to this annotation. For this property to hold, the following must be true of o:
  • The object is also an instance of the same annotation type.
  • The members of the supplied annotation are equal to those of this annotation, according to the following:
    • If the members are floats, then, for floats x and y, Float.valueOf(x).equals(Float.valueOf(y) must return true. This differs from the usual (==) comparison in that NaN is considered equal to itself and positive and negative zero are seen as different.
    • Likewise, if the members are doubles, then, for doubles x and y, Double.valueOf(x).equals(Double.valueOf(y) must return true. This differs from the usual (==) comparison in that NaN is considered equal to itself and positive and negative zero are seen as different.
    • Strings, classes, enumerations and annotations are considered equal according to the equals() implementation for these types.
    • Arrays are considered equal according to Arrays.equals()
    • Any remaining types are considered equal using ==.
    Overrides:
    equals in interface Object
    Parameters:
    o - the object to compare with this annotation.
    Returns:
    true if the supplied object is an annotation with equivalent members.

    extends Annotation> annotationType

    public Classextends Annotation> annotationType()
    Returns the type of this annotation.
    Returns:
    the class of which this annotation is an instance.

    hashCode

    public int hashCode()
    Returns the hash code of the annotation. This is computed as the sum of the hash codes of the annotation's members.

    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 v and the name is n, the hash code of the member is v.hashCode() XOR (127 * String.hashCode(n)). v.hashCode() is defined as follows:

    • The hash code of a primitive value (i.e. byte, char, double, float, int, long, short and boolean) is the hash code obtained from its corresponding wrapper class using valueOf(v).hashCode(), where v is the primitive value.
    • The hash code of an enumeration, string, class or other annotation is obtained using v.hashCode().
    • The hash code of an array is computed using Arrays.hashCode(v).
    Overrides:
    hashCode in interface Object
    Returns:
    the hash code of the annotation, computed as the sum of its member hashcodes.

    toString

    public String toString()
    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.
    Overrides:
    toString in interface Object
    Returns:
    a textual representation of the annotation.

    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.