java.lang.reflect
Class Field
- Member
boolean | equals(Object o) - Determine whether this Object is semantically equal
to another Object.
|
Object | get(Object o)
|
boolean | getBoolean(Object o)
|
byte | getByte(Object o)
|
char | getChar(Object o)
|
Class | getDeclaringClass() - Gets the class that declared this member.
|
double | getDouble(Object o)
|
float | getFloat(Object o)
|
int | getInt(Object o)
|
long | getLong(Object o)
|
int | getModifiers() - Gets the modifiers this member uses.
|
String | getName() - Gets the simple name of this member.
|
short | getShort(Object o)
|
Class | getType()
|
int | hashCode() - Get a value that represents this Object, as uniquely as
possible within the confines of an int.
|
void | set(Object o, Object value)
|
void | setBoolean(Object o, boolean value)
|
void | setByte(Object o, byte value)
|
void | setChar(Object o, char value)
|
void | setDouble(Object o, double value)
|
void | setFloat(Object o, float value)
|
void | setInt(Object o, int value)
|
void | setLong(Object o, long value)
|
void | setShort(Object o, short value)
|
String | toString() - Convert this Object to a human-readable String.
|
clone , equals , finalize , getClass , hashCode , notify , notifyAll , toString , wait , wait , wait |
equals
public boolean equals(Object o)
Determine whether this Object is semantically equal
to another Object.
There are some fairly strict requirements on this
method which subclasses must follow:
- It must be transitive. If
a.equals(b)
and
b.equals(c)
, then a.equals(c)
must be true as well.
- It must be symmetric.
a.equals(b)
and
b.equals(a)
must have the same value.
- It must be reflexive.
a.equals(a)
must
always be true.
- It must be consistent. Whichever value a.equals(b)
returns on the first invocation must be the value
returned on all later invocations.
a.equals(null)
must be false.
- It must be consistent with hashCode(). That is,
a.equals(b)
must imply
a.hashCode() == b.hashCode()
.
The reverse is not true; two objects that are not
equal may have the same hashcode, but that has
the potential to harm hashing performance.
This is typically overridden to throw a
ClassCastException
if the argument is not comparable to the class performing
the comparison, but that is not a requirement. It is legal
for
a.equals(b)
to be true even though
a.getClass() != b.getClass()
. Also, it
is typical to never cause a
NullPointerException
.
In general, the Collections API (
java.util
) use the
equals
method rather than the
==
operator to compare objects. However,
IdentityHashMap
is an exception to this rule, for its own good reasons.
The default implementation returns
this == o
.
- equals in interface Object
- whether this Object is semantically equal to another
Object.hashCode()
getDeclaringClass
public Class getDeclaringClass()
Gets the class that declared this member. This is not the class where
this method was called, or even the class where this Member object
came to life, but the class that declares the member this represents.
- getDeclaringClass in interface Member
- the class that declared this member
getModifiers
public int getModifiers()
Gets the modifiers this member uses. Use the Modifier
class to interpret the values.
- getModifiers in interface Member
- an integer representing the modifiers to this Member
Modifier
getName
public String getName()
Gets the simple name of this member. This will be a valid Java
identifier, with no qualification.
- getName in interface Member
- the name of this member
hashCode
public int hashCode()
Get a value that represents this Object, as uniquely as
possible within the confines of an int.
There are some requirements on this method which
subclasses must follow:
- Semantic equality implies identical hashcodes. In other
words, if
a.equals(b)
is true, then
a.hashCode() == b.hashCode()
must be as well.
However, the reverse is not necessarily true, and two
objects may have the same hashcode without being equal.
- It must be consistent. Whichever value o.hashCode()
returns on the first invocation must be the value
returned on all later invocations as long as the object
exists. Notice, however, that the result of hashCode may
change between separate executions of a Virtual Machine,
because it is not invoked on the same object.
Notice that since
hashCode
is used in
Hashtable
and other hashing classes,
a poor implementation will degrade the performance of hashing
(so don't blindly implement it as returning a constant!). Also,
if calculating the hash is time-consuming, a class may consider
caching the results.
The default implementation returns
System.identityHashCode(this)
- hashCode in interface Object
- the hash code for this Object
Object.equals(Object)
, System.identityHashCode(Object)
toString
public String toString()
Convert this Object to a human-readable String.
There are no limits placed on how long this String
should be or what it should contain. We suggest you
make it as intuitive as possible to be able to place
it into
System.out.println()
and such.
It is typical, but not required, to ensure that this method
never completes abruptly with a
RuntimeException
.
This method will be called when performing string
concatenation with this object. If the result is
null
, string concatenation will instead
use
"null"
.
The default implementation returns
getClass().getName() + "@" +
Integer.toHexString(hashCode())
.
- toString in interface Object
- the String representing this Object, which may be null
Object.getClass()
, Object.hashCode()
, Class.getName()
, Integer.toHexString(int)
java.lang.reflect.Field - reflection of Java fields
Copyright (C) 1998, 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., 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.