<s>
Java	B-Language
Platform	I-Language
,	I-Language
Standard	I-Language
Edition	I-Language
(	O
Java	B-Language
SE	I-Language
)	O
is	O
a	O
computing	B-Device
platform	I-Device
for	O
development	O
and	O
deployment	O
of	O
portable	O
code	O
for	O
desktop	B-Device
and	O
server	B-Application
environments	O
.	O
</s>
<s>
Java	B-Language
SE	I-Language
was	O
formerly	O
known	O
as	O
Java	B-Language
2	I-Language
Platform	I-Language
,	I-Language
Standard	I-Language
Edition	I-Language
(	O
J2SE	B-Language
)	O
.	O
</s>
<s>
The	O
platform	O
uses	O
Java	B-Language
programming	I-Language
language	I-Language
and	O
is	O
part	O
of	O
the	O
Java	B-Device
software-platform	I-Device
family	O
.	O
</s>
<s>
Java	B-Language
SE	I-Language
defines	O
a	O
range	O
of	O
general-purpose	O
APIs	B-General_Concept
—	O
such	O
as	O
Java	B-Language
APIs	I-Language
for	O
the	O
Java	B-Library
Class	I-Library
Library	I-Library
—	O
and	O
also	O
includes	O
the	O
Java	B-Language
Language	I-Language
Specification	I-Language
and	O
the	O
Java	B-Language
Virtual	I-Language
Machine	I-Language
Specification	I-Language
.	O
</s>
<s>
OpenJDK	B-Language
is	O
the	O
official	O
reference	O
implementation	O
since	O
version	O
7	O
.	O
</s>
<s>
The	O
platform	O
was	O
known	O
as	O
Java	B-Language
2	I-Language
Platform	I-Language
,	I-Language
Standard	I-Language
Edition	I-Language
or	O
J2SE	B-Language
from	O
version	O
1.2	O
,	O
until	O
the	O
name	O
was	O
changed	O
to	O
Java	B-Language
Platform	I-Language
,	I-Language
Standard	I-Language
Edition	I-Language
or	O
Java	B-Language
SE	I-Language
in	O
version	O
1.5	O
.	O
</s>
<s>
The	O
"	O
SE	O
"	O
is	O
used	O
to	O
distinguish	O
the	O
base	O
platform	O
from	O
the	O
Enterprise	O
Edition	O
(	O
Java	B-Language
EE	I-Language
)	O
and	O
Micro	O
Edition	O
(	O
Java	B-Language
ME	I-Language
)	O
platforms	B-Device
.	O
</s>
<s>
The	O
naming	O
convention	O
has	O
been	O
changed	O
several	O
times	O
over	O
the	O
Java	B-Language
version	O
history	O
.	O
</s>
<s>
Starting	O
with	O
J2SE	B-Language
1.4	O
(	O
Merlin	O
)	O
,	O
Java	B-Language
SE	I-Language
has	O
been	O
developed	O
under	O
the	O
Java	B-Language
Community	I-Language
Process	I-Language
,	O
which	O
produces	O
descriptions	O
of	O
proposed	O
and	O
final	O
specifications	O
for	O
the	O
Java	B-Device
platform	I-Device
called	O
Java	B-Language
Specification	I-Language
Requests	I-Language
(	O
JSR	O
)	O
.	O
</s>
<s>
JSR	B-Language
59	I-Language
was	O
the	O
umbrella	O
specification	O
for	O
J2SE	B-Language
1.4	O
and	O
JSR	B-Language
176	I-Language
specified	O
J2SE	B-Language
5.0	O
(	O
Tiger	O
)	O
.	O
</s>
<s>
Java	B-Language
SE	I-Language
6	O
(	O
Mustang	O
)	O
was	O
released	O
under	O
JSR	B-Language
270	I-Language
.	O
</s>
<s>
Java	B-Language
Platform	I-Language
,	I-Language
Enterprise	I-Language
Edition	I-Language
(	O
Java	B-Language
EE	I-Language
)	O
is	O
a	O
related	O
specification	O
that	O
includes	O
all	O
the	O
classes	O
in	O
Java	B-Language
SE	I-Language
,	O
plus	O
a	O
number	O
that	O
are	O
more	O
useful	O
to	O
programs	O
that	O
run	O
on	O
servers	O
as	O
opposed	O
to	O
workstations	B-Device
.	O
</s>
<s>
Java	B-Language
Platform	I-Language
,	I-Language
Micro	I-Language
Edition	I-Language
(	O
Java	B-Language
ME	I-Language
)	O
is	O
a	O
related	O
specification	O
intended	O
to	O
provide	O
a	O
certified	O
collection	O
of	O
Java	B-Language
APIs	I-Language
for	O
the	O
development	O
of	O
software	O
for	O
small	O
,	O
resource-constrained	O
devices	O
such	O
as	O
cell	O
phones	O
,	O
PDAs	B-Application
and	O
set-top	O
boxes	O
.	O
</s>
<s>
The	O
Java	B-Language
Runtime	I-Language
Environment	O
(	O
JRE	O
)	O
and	O
Java	B-Language
Development	I-Language
Kit	I-Language
(	O
JDK	B-Language
)	O
are	O
the	O
actual	O
files	B-Operating_System
downloaded	O
and	O
installed	O
on	O
a	O
computer	O
to	O
run	O
or	O
develop	O
Java	B-Language
programs	O
,	O
respectively	O
.	O
</s>
<s>
The	O
Java	B-Language
package	I-Language
contains	O
fundamental	O
classes	O
and	O
interfaces	B-Language
closely	O
tied	O
to	O
the	O
language	O
and	O
runtime	B-Device
system	I-Device
.	O
</s>
<s>
This	O
includes	O
the	O
root	O
classes	O
that	O
form	O
the	O
class	B-Application
hierarchy	I-Application
,	O
types	O
tied	O
to	O
the	O
language	O
definition	O
,	O
basic	O
exceptions	B-General_Concept
,	O
math	O
functions	O
,	O
threading	B-Operating_System
,	O
security	O
functions	O
,	O
as	O
well	O
as	O
some	O
information	O
on	O
the	O
underlying	O
native	O
system	O
.	O
</s>
<s>
This	O
package	O
contains	O
22	O
of	O
32	O
Error	O
classes	O
provided	O
in	O
JDK	B-Language
6	O
.	O
</s>
<s>
The	O
main	O
classes	O
and	O
interfaces	B-Language
in	O
java.lang	O
are	O
:	O
</s>
<s>
–	O
the	O
class	O
that	O
is	O
the	O
root	O
of	O
every	O
class	B-Application
hierarchy	I-Application
.	O
</s>
<s>
–	O
the	O
base	O
class	O
for	O
enumeration	B-Language
classes	I-Language
(	O
as	O
of	O
J2SE	B-Language
5.0	O
)	O
.	O
</s>
<s>
–	O
the	O
class	O
that	O
is	O
the	O
root	O
of	O
the	O
Java	B-Language
reflection	B-Language
system	O
.	O
</s>
<s>
–	O
the	O
class	O
that	O
is	O
the	O
base	O
class	O
of	O
the	O
exception	O
class	B-Application
hierarchy	I-Application
.	O
</s>
<s>
–	O
the	O
class	O
that	O
allows	O
operations	O
on	O
threads	B-Operating_System
.	O
</s>
<s>
–	O
the	O
class	O
for	O
strings	O
and	O
string	B-Language
literals	I-Language
.	O
</s>
<s>
and	O
–	O
classes	O
for	O
performing	O
string	O
manipulation	O
(	O
StringBuilder	O
as	O
of	O
J2SE	B-Language
5.0	O
)	O
.	O
</s>
<s>
–	O
the	O
interface	O
that	O
allows	O
generic	O
comparison	O
and	O
ordering	O
of	O
objects	O
(	O
as	O
of	O
J2SE	B-Language
1.2	O
)	O
.	O
</s>
<s>
–	O
the	O
interface	O
that	O
allows	O
generic	O
iteration	O
using	O
the	O
enhanced	O
for	O
loop	O
(	O
as	O
of	O
J2SE	B-Language
5.0	O
)	O
.	O
</s>
<s>
,	O
,	O
,	O
,	O
and	O
–	O
classes	O
that	O
provide	O
"	O
system	O
operations	O
"	O
that	O
manage	O
the	O
dynamic	B-Operating_System
loading	I-Operating_System
of	O
classes	O
,	O
creation	O
of	O
external	O
processes	B-Operating_System
,	O
host	O
environment	O
inquiries	O
such	O
as	O
the	O
time	O
of	O
day	O
,	O
and	O
enforcement	O
of	O
security	O
policies	O
.	O
</s>
<s>
and	O
–	O
classes	O
that	O
provide	O
basic	O
math	O
functions	O
such	O
as	O
sine	O
,	O
cosine	O
,	O
and	O
square	O
root	O
(	O
StrictMath	O
as	O
of	O
J2SE	B-Language
1.3	O
)	O
.	O
</s>
<s>
The	O
primitive	B-Language
wrapper	I-Language
classes	O
that	O
encapsulate	B-Application
primitive	O
types	O
as	O
objects	O
.	O
</s>
<s>
The	O
basic	O
exception	O
classes	O
thrown	O
for	O
language-level	O
and	O
other	O
common	O
exceptions	B-General_Concept
.	O
</s>
<s>
Classes	O
in	O
java.lang	O
are	O
automatically	O
imported	O
into	O
every	O
source	O
file	B-Operating_System
.	O
</s>
<s>
The	O
package	O
provides	O
more	O
flexible	O
types	O
of	O
references	O
than	O
are	O
otherwise	O
available	O
,	O
permitting	O
limited	O
interaction	O
between	O
the	O
application	O
and	O
the	O
Java	B-Language
Virtual	I-Language
Machine	I-Language
(	O
JVM	B-Language
)	O
garbage	B-General_Concept
collector	I-General_Concept
.	O
</s>
<s>
It	O
is	O
an	O
important	O
package	O
,	O
central	O
enough	O
to	O
the	O
language	O
for	O
the	O
language	O
designers	O
to	O
give	O
it	O
a	O
name	O
that	O
starts	O
with	O
"	O
java.lang	O
"	O
,	O
but	O
it	O
is	O
somewhat	O
special-purpose	O
and	O
not	O
used	O
by	O
a	O
lot	O
of	O
developers	O
.	O
</s>
<s>
This	O
package	O
was	O
added	O
in	O
J2SE	B-Language
1.2	O
.	O
</s>
<s>
Java	B-Language
has	O
an	O
expressive	O
system	O
of	O
references	O
and	O
allows	O
for	O
special	O
behavior	O
for	O
garbage	B-General_Concept
collection	I-General_Concept
.	O
</s>
<s>
A	O
normal	O
reference	O
in	O
Java	B-Language
is	O
known	O
as	O
a	O
"	O
strong	O
reference.	O
"	O
</s>
<s>
The	O
java.lang.ref	O
package	O
defines	O
three	O
other	O
types	O
of	O
references	O
—	O
soft	O
,	O
weak	B-General_Concept
,	O
and	O
phantom	O
references	O
.	O
</s>
<s>
A	O
can	O
be	O
used	O
to	O
implement	O
a	O
cache	B-General_Concept
.	O
</s>
<s>
An	O
object	O
that	O
is	O
not	O
reachable	O
by	O
a	O
strong	B-General_Concept
reference	I-General_Concept
(	O
that	O
is	O
,	O
not	O
strongly	O
reachable	O
)	O
,	O
but	O
is	O
referenced	O
by	O
a	O
soft	O
reference	O
is	O
called	O
"	O
softly	O
reachable.	O
"	O
</s>
<s>
A	O
softly	O
reachable	O
object	O
may	O
be	O
garbage	B-General_Concept
collected	I-General_Concept
at	O
the	O
discretion	O
of	O
the	O
garbage	B-General_Concept
collector	I-General_Concept
.	O
</s>
<s>
This	O
generally	O
means	O
that	O
softly	O
reachable	O
objects	O
are	O
only	O
garbage	B-General_Concept
collected	I-General_Concept
when	O
free	O
memory	O
is	O
low	O
—	O
but	O
again	O
,	O
this	O
is	O
at	O
the	O
garbage	B-General_Concept
collector	I-General_Concept
's	O
discretion	O
.	O
</s>
<s>
A	O
is	O
used	O
to	O
implement	O
weak	B-General_Concept
maps	I-General_Concept
.	O
</s>
<s>
An	O
object	O
that	O
is	O
not	O
strongly	O
or	O
softly	O
reachable	O
,	O
but	O
is	O
referenced	O
by	O
a	O
weak	B-General_Concept
reference	I-General_Concept
is	O
called	O
"	O
weakly	B-General_Concept
reachable	I-General_Concept
"	O
.	O
</s>
<s>
A	O
weakly	B-General_Concept
reachable	I-General_Concept
object	O
is	O
garbage	B-General_Concept
collected	I-General_Concept
in	O
the	O
next	O
collection	O
cycle	O
.	O
</s>
<s>
A	O
weak	B-General_Concept
map	I-General_Concept
allows	O
the	O
programmer	O
to	O
put	O
key/value	O
pairs	O
in	O
the	O
map	O
and	O
not	O
worry	O
about	O
the	O
objects	O
taking	O
up	O
memory	O
when	O
the	O
key	O
is	O
no	O
longer	O
reachable	O
anywhere	O
else	O
.	O
</s>
<s>
Another	O
possible	O
application	O
of	O
weak	B-General_Concept
references	I-General_Concept
is	O
the	O
string	O
intern	O
pool	O
.	O
</s>
<s>
Semantically	O
,	O
a	O
weak	B-General_Concept
reference	I-General_Concept
means	O
"	O
get	O
rid	O
of	O
this	O
object	O
when	O
nothing	O
else	O
references	O
it	O
at	O
the	O
next	O
garbage	O
collection.	O
"	O
</s>
<s>
A	O
is	O
used	O
to	O
reference	O
objects	O
that	O
have	O
been	O
marked	O
for	O
garbage	B-General_Concept
collection	I-General_Concept
and	O
have	O
been	O
finalized	B-Application
,	O
but	O
have	O
not	O
yet	O
been	O
reclaimed	O
.	O
</s>
<s>
An	O
object	O
that	O
is	O
not	O
strongly	O
,	O
softly	O
or	O
weakly	B-General_Concept
reachable	I-General_Concept
,	O
but	O
is	O
referenced	O
by	O
a	O
phantom	O
reference	O
is	O
called	O
"	O
phantom	O
reachable.	O
"	O
</s>
<s>
Semantically	O
,	O
a	O
phantom	O
reference	O
means	O
"	O
this	O
object	O
is	O
no	O
longer	O
needed	O
and	O
has	O
been	O
finalized	B-Application
in	O
preparation	O
for	O
being	O
collected.	O
"	O
</s>
<s>
Each	O
of	O
these	O
reference	O
types	O
extends	O
the	O
class	O
,	O
which	O
provides	O
the	O
method	B-Language
to	O
return	O
a	O
strong	B-General_Concept
reference	I-General_Concept
to	O
the	O
referent	O
object	O
(	O
or	O
null	O
if	O
the	O
reference	O
has	O
been	O
cleared	O
or	O
if	O
the	O
reference	O
type	O
is	O
phantom	O
)	O
,	O
and	O
the	O
method	B-Language
to	O
clear	O
the	O
reference	O
.	O
</s>
<s>
The	O
java.lang.ref	O
also	O
defines	O
the	O
class	O
,	O
which	O
can	O
be	O
used	O
in	O
each	O
of	O
the	O
applications	O
discussed	O
above	O
to	O
keep	O
track	O
of	O
objects	O
that	O
have	O
changed	O
reference	O
type	O
.	O
</s>
<s>
Reflection	B-Language
is	O
a	O
constituent	O
of	O
the	O
Java	B-Language
API	I-Language
that	O
lets	O
Java	B-Language
code	I-Language
examine	O
and	O
"	O
reflect	O
"	O
on	O
Java	B-Language
components	O
at	O
runtime	B-Device
and	O
use	O
the	O
reflected	O
members	O
.	O
</s>
<s>
Classes	O
in	O
the	O
package	O
,	O
along	O
with	O
java.lang.Class	O
and	O
accommodate	O
applications	O
such	O
as	O
debuggers	B-Application
,	O
interpreters	B-Application
,	O
object	O
inspectors	O
,	O
class	B-Application
browsers	I-Application
,	O
and	O
services	O
such	O
as	O
object	B-Application
serialization	I-Application
and	O
JavaBeans	O
that	O
need	O
access	O
to	O
either	O
the	O
public	O
members	O
of	O
a	O
target	O
object	O
(	O
based	O
on	O
its	O
runtime	B-Device
class	O
)	O
or	O
the	O
members	O
declared	O
by	O
a	O
given	O
class	O
.	O
</s>
<s>
This	O
package	O
was	O
added	O
in	O
JDK	B-Language
1.1	O
.	O
</s>
<s>
Reflection	B-Language
is	O
used	O
to	O
instantiate	O
classes	O
and	O
invoke	O
methods	O
using	O
their	O
names	O
,	O
a	O
concept	O
that	O
allows	O
for	O
dynamic	O
programming	O
.	O
</s>
<s>
Classes	O
,	O
interfaces	B-Language
,	O
methods	O
,	O
fields	B-Application
,	O
and	O
constructors	O
can	O
all	O
be	O
discovered	O
and	O
used	O
at	O
runtime	B-Device
.	O
</s>
<s>
Reflection	B-Language
is	O
supported	O
by	O
metadata	O
that	O
the	O
JVM	B-Language
has	O
about	O
the	O
program	O
.	O
</s>
<s>
There	O
are	O
basic	O
techniques	O
involved	O
in	O
reflection	B-Language
:	O
</s>
<s>
Discovery	O
–	O
this	O
involves	O
taking	O
an	O
object	O
or	O
class	O
and	O
discovering	O
the	O
members	O
,	O
superclasses	O
,	O
implemented	O
interfaces	B-Language
,	O
and	O
then	O
possibly	O
using	O
the	O
discovered	O
elements	O
.	O
</s>
<s>
Discovery	O
typically	O
starts	O
with	O
an	O
object	O
and	O
calling	O
the	O
method	B-Language
to	O
get	O
the	O
object	O
's	O
Class	O
.	O
</s>
<s>
–	O
returns	O
an	O
array	O
of	O
Class	O
objects	O
representing	O
all	O
the	O
public	O
classes	O
and	O
interfaces	B-Language
that	O
are	O
members	O
(	O
e.g.	O
</s>
<s>
With	O
a	O
Class	O
object	O
,	O
member	O
Method	B-Language
,	O
Constructor	O
,	O
or	O
Field	O
objects	O
can	O
be	O
obtained	O
using	O
the	O
symbolic	O
name	O
of	O
the	O
member	O
.	O
</s>
<s>
–	O
returns	O
the	O
Method	B-Language
object	O
representing	O
the	O
public	O
method	B-Language
with	O
the	O
name	O
"	O
methodName	O
"	O
of	O
the	O
class	O
or	O
interface	O
that	O
accepts	O
the	O
parameters	O
specified	O
by	O
the	O
Class	O
...	O
parameters	O
.	O
</s>
<s>
–	O
returns	O
the	O
Constructor	O
object	O
representing	O
the	O
public	O
constructor	O
of	O
the	O
class	O
that	O
accepts	O
the	O
parameters	O
specified	O
by	O
the	O
Class	O
...	O
parameters	O
.	O
</s>
<s>
Method	B-Language
,	O
Constructor	O
,	O
and	O
Field	O
objects	O
can	O
be	O
used	O
to	O
dynamically	O
access	O
the	O
represented	O
member	O
of	O
the	O
class	O
.	O
</s>
<s>
–	O
returns	O
an	O
Object	O
containing	O
the	O
result	O
of	O
invoking	O
the	O
method	B-Language
for	O
the	O
instance	O
of	O
the	O
first	O
Object	O
parameter	O
passed	O
to	O
invoke( )	O
.	O
</s>
<s>
The	O
remaining	O
Object	O
...	O
parameters	O
are	O
passed	O
to	O
the	O
method	B-Language
.	O
</s>
<s>
(	O
If	O
the	O
Method	B-Language
object	O
represents	O
a	O
static	O
method	B-Language
then	O
the	O
first	O
Object	O
parameter	O
is	O
ignored	O
and	O
may	O
be	O
null	O
.	O
)	O
</s>
<s>
The	O
Object	O
...	O
parameters	O
are	O
passed	O
to	O
the	O
constructor	O
.	O
</s>
<s>
The	O
java.lang.reflect	O
package	O
also	O
provides	O
an	O
class	O
that	O
contains	O
static	B-Language
methods	I-Language
for	O
creating	O
and	O
manipulating	O
array	O
objects	O
,	O
and	O
since	O
J2SE	B-Language
1.3	O
,	O
a	O
class	O
that	O
supports	O
dynamic	O
creation	O
of	O
proxy	O
classes	O
that	O
implement	O
specified	O
interfaces	B-Language
.	O
</s>
<s>
The	O
implementation	O
of	O
a	O
Proxy	O
class	O
is	O
provided	O
by	O
a	O
supplied	O
object	O
that	O
implements	B-Language
the	O
interface	O
.	O
</s>
<s>
The	O
InvocationHandler	O
's	O
method	B-Language
is	O
called	O
for	O
each	O
method	B-Language
invoked	O
on	O
the	O
proxy	O
object	O
—	O
the	O
first	O
parameter	O
is	O
the	O
proxy	O
object	O
,	O
the	O
second	O
parameter	O
is	O
the	O
Method	B-Language
object	O
representing	O
the	O
method	B-Language
from	O
the	O
interface	O
implemented	O
by	O
the	O
proxy	O
,	O
and	O
the	O
third	O
parameter	O
is	O
the	O
array	O
of	O
parameters	O
passed	O
to	O
the	O
interface	O
method	B-Language
.	O
</s>
<s>
The	O
invoke( )	O
method	B-Language
returns	O
an	O
Object	O
result	O
that	O
contains	O
the	O
result	O
returned	O
to	O
the	O
code	O
that	O
called	O
the	O
proxy	O
interface	O
method	B-Language
.	O
</s>
<s>
The	O
package	O
contains	O
classes	O
that	O
support	O
input	B-General_Concept
and	I-General_Concept
output	I-General_Concept
.	O
</s>
<s>
The	O
classes	O
in	O
the	O
package	O
are	O
primarily	O
stream-oriented	B-Architecture
;	O
however	O
,	O
a	O
class	O
for	O
random	B-General_Concept
access	I-General_Concept
files	I-General_Concept
is	O
also	O
provided	O
.	O
</s>
<s>
The	O
central	O
classes	O
in	O
the	O
package	O
are	O
and	O
,	O
which	O
are	O
abstract	O
base	O
classes	O
for	O
reading	O
from	O
and	O
writing	O
to	O
byte	B-Application
streams	O
,	O
respectively	O
.	O
</s>
<s>
The	O
package	O
also	O
has	O
a	O
few	O
miscellaneous	O
classes	O
to	O
support	O
interactions	O
with	O
the	O
host	O
file	B-Application
system	I-Application
.	O
</s>
<s>
The	O
following	O
table	O
shows	O
the	O
sources/destinations	O
supported	O
directly	O
by	O
the	O
java.io	O
package	O
:	O
</s>
<s>
Source/Destination	O
Name	O
Stream	O
types	O
In/Out	O
Classes	O
byte	B-Application
array	O
(	O
byte[]	O
)	O
ByteArray	O
byte	B-Application
in	O
,	O
out	O
,	O
char	O
array	O
(	O
char[]	O
)	O
CharArray	O
char	O
in	O
,	O
out	O
,	O
file	B-Operating_System
File	B-Operating_System
byte	B-Application
,	O
char	O
in	O
,	O
out	O
,	O
,	O
,	O
string	O
(	O
StringBuffer	O
)	O
String	O
char	O
in	O
,	O
out	O
,	O
thread	B-Operating_System
(	O
Thread	B-Operating_System
)	O
Piped	O
byte	B-Application
,	O
char	O
in	O
,	O
out	O
,	O
,	O
,	O
</s>
<s>
Other	O
standard	O
library	O
packages	O
provide	O
stream	O
implementations	O
for	O
other	O
destinations	O
,	O
such	O
as	O
the	O
InputStream	O
returned	O
by	O
the	O
method	B-Language
or	O
the	O
Java	B-Language
EE	I-Language
class	O
.	O
</s>
<s>
Data	O
type	O
handling	O
and	O
processing	O
or	O
filtering	O
of	O
stream	O
data	O
is	O
accomplished	O
through	O
stream	O
filters	B-Application
.	O
</s>
<s>
Filters	B-Application
are	O
created	O
by	O
extending	O
one	O
of	O
the	O
base	O
filter	O
classes	O
,	O
,	O
,	O
or	O
.	O
</s>
<s>
The	O
Reader	O
and	O
Writer	O
classes	O
are	O
really	O
just	O
byte	B-Application
streams	O
with	O
additional	O
processing	O
performed	O
on	O
the	O
data	O
stream	O
to	O
convert	O
the	O
bytes	B-Application
to	O
characters	O
.	O
</s>
<s>
They	O
use	O
the	O
default	O
character	B-General_Concept
encoding	I-General_Concept
for	O
the	O
platform	O
,	O
which	O
as	O
of	O
J2SE	B-Language
5.0	O
is	O
represented	O
by	O
the	O
returned	O
by	O
the	O
static	O
method	B-Language
.	O
</s>
<s>
Both	O
these	O
classes	O
have	O
constructors	O
that	O
support	O
specifying	O
the	O
character	B-General_Concept
encoding	I-General_Concept
to	O
use	O
.	O
</s>
<s>
The	O
following	O
table	O
shows	O
the	O
other	O
processes	B-Operating_System
and	O
filters	B-Application
that	O
the	O
java.io	O
package	O
directly	O
supports	O
.	O
</s>
<s>
Operation	O
Name	O
Stream	O
types	O
In/Out	O
Classes	O
buffering	B-General_Concept
Buffered	O
byte	B-Application
,	O
char	O
in	O
,	O
out	O
,	O
,	O
,	O
"	O
push	O
back	O
"	O
last	O
value	O
read	O
Pushback	O
byte	B-Application
,	O
char	O
in	O
,	O
read/write	O
primitive	O
types	O
Data	O
byte	B-Application
in	O
,	O
out	O
,	O
object	B-Application
serialization	I-Application
(	O
read/write	O
objects	O
)	O
Object	O
byte	B-Application
in	O
,	O
out	O
,	O
</s>
<s>
The	O
class	O
supports	O
random	B-General_Concept
access	I-General_Concept
reading	O
and	O
writing	O
of	O
files	B-Operating_System
.	O
</s>
<s>
The	O
class	O
uses	O
a	O
file	B-Operating_System
pointer	O
that	O
represents	O
a	O
byte-offset	O
within	O
the	O
file	B-Operating_System
for	O
the	O
next	O
read	O
or	O
write	O
operation	O
.	O
</s>
<s>
The	O
file	B-Operating_System
pointer	O
is	O
moved	O
implicitly	O
by	O
reading	O
or	O
writing	O
and	O
explicitly	O
by	O
calling	O
the	O
or	O
methods	O
.	O
</s>
<s>
The	O
current	O
position	O
of	O
the	O
file	B-Operating_System
pointer	O
is	O
returned	O
by	O
the	O
method	B-Language
.	O
</s>
<s>
The	O
class	O
represents	O
a	O
file	B-Operating_System
or	O
directory	B-Application
path	I-Application
in	O
a	O
file	B-Application
system	I-Application
.	O
</s>
<s>
File	B-Operating_System
objects	O
support	O
the	O
creation	O
,	O
deletion	O
and	O
renaming	O
of	O
files	B-Operating_System
and	O
directories	B-Application
and	O
the	O
manipulation	O
of	O
file	B-Application
attributes	I-Application
such	O
as	O
read-only	O
and	O
last	O
modified	O
timestamp	O
.	O
</s>
<s>
File	B-Operating_System
objects	O
that	O
represent	O
directories	B-Application
can	O
be	O
used	O
to	O
get	O
a	O
list	O
of	O
all	O
the	O
contained	O
files	B-Operating_System
and	O
directories	B-Application
.	O
</s>
<s>
The	O
class	O
is	O
a	O
file	B-Application
descriptor	I-Application
that	O
represents	O
a	O
source	O
or	O
sink	O
(	O
destination	O
)	O
of	O
bytes	B-Application
.	O
</s>
<s>
Typically	O
this	O
is	O
a	O
file	B-Operating_System
,	O
but	O
can	O
also	O
be	O
a	O
console	B-Device
or	O
network	B-Protocol
socket	I-Protocol
.	O
</s>
<s>
FileDescriptor	O
objects	O
are	O
used	O
to	O
create	O
File	B-Architecture
streams	I-Architecture
.	O
</s>
<s>
They	O
are	O
obtained	O
from	O
File	B-Architecture
streams	I-Architecture
and	O
java.net	O
sockets	O
and	O
datagram	O
sockets	O
.	O
</s>
<s>
In	O
J2SE	B-Language
1.4	O
,	O
the	O
package	O
(	O
NIO	O
or	O
Non-blocking	O
I/O	B-General_Concept
)	O
was	O
added	O
to	O
support	O
memory-mapped	B-Architecture
I/O	I-Architecture
,	O
facilitating	O
I/O	B-General_Concept
operations	I-General_Concept
closer	O
to	O
the	O
underlying	O
hardware	O
with	O
sometimes	O
dramatically	O
better	O
performance	O
.	O
</s>
<s>
The	O
java.nio	O
package	O
provides	O
support	O
for	O
a	O
number	O
of	O
buffer	B-General_Concept
types	O
.	O
</s>
<s>
The	O
subpackage	O
provides	O
support	O
for	O
different	O
character	B-General_Concept
encodings	I-General_Concept
for	O
character	O
data	O
.	O
</s>
<s>
The	O
subpackage	O
provides	O
support	O
for	O
channels	O
,	O
which	O
represent	O
connections	O
to	O
entities	O
that	O
are	O
capable	O
of	O
performing	O
I/O	B-General_Concept
operations	I-General_Concept
,	O
such	O
as	O
files	B-Operating_System
and	O
sockets	O
.	O
</s>
<s>
The	O
java.nio.channels	O
package	O
also	O
provides	O
support	O
for	O
fine-grained	O
locking	O
of	O
files	B-Operating_System
.	O
</s>
<s>
The	O
package	O
supports	O
multiprecision	B-Algorithm
arithmetic	I-Algorithm
(	O
including	O
modular	O
arithmetic	O
operations	O
)	O
and	O
provides	O
multiprecision	B-Algorithm
prime	O
number	O
generators	O
used	O
for	O
cryptographic	O
key	O
generation	O
.	O
</s>
<s>
–	O
provides	O
arbitrary-precision	B-Algorithm
signed	O
decimal	O
numbers	O
.	O
</s>
<s>
–	O
provides	O
arbitrary-precision	B-Algorithm
integers	O
.	O
</s>
<s>
Operations	O
on	O
BigInteger	O
do	O
not	O
overflow	B-Algorithm
or	O
lose	O
precision	O
.	O
</s>
<s>
In	O
addition	O
to	O
standard	O
arithmetic	O
operations	O
,	O
it	O
provides	O
modular	O
arithmetic	O
,	O
GCD	O
calculation	O
,	O
primality	B-Algorithm
testing	I-Algorithm
,	O
prime	O
number	O
generation	O
,	O
bit	O
manipulation	O
,	O
and	O
other	O
miscellaneous	O
operations	O
.	O
</s>
<s>
–	O
encapsulate	B-Application
the	O
context	O
settings	O
that	O
describe	O
certain	O
rules	O
for	O
numerical	O
operators	O
.	O
</s>
<s>
–	O
an	O
enumeration	B-Language
that	O
provides	O
eight	O
rounding	O
behaviors	O
.	O
</s>
<s>
The	O
package	O
provides	O
special	O
IO	O
routines	O
for	O
networks	O
,	O
allowing	O
HTTP	B-Protocol
requests	I-Protocol
,	O
as	O
well	O
as	O
other	O
common	O
transactions	O
.	O
</s>
<s>
The	O
package	O
implements	B-Language
parsing	O
routines	O
for	O
strings	O
and	O
supports	O
various	O
human-readable	O
languages	O
and	O
locale-specific	O
parsing	O
.	O
</s>
<s>
Data	B-General_Concept
structures	I-General_Concept
that	O
aggregate	O
objects	O
are	O
the	O
focus	O
of	O
the	O
package	O
.	O
</s>
<s>
Included	O
in	O
the	O
package	O
is	O
the	O
Collections	B-Language
API	I-Language
,	O
an	O
organized	O
data	B-General_Concept
structure	I-General_Concept
hierarchy	O
influenced	O
heavily	O
by	O
the	O
design	O
patterns	O
considerations	O
.	O
</s>
<s>
Created	O
to	O
support	O
Java	B-Application
applet	I-Application
creation	O
,	O
the	O
package	O
lets	O
applications	O
be	O
downloaded	O
over	O
a	O
network	O
and	O
run	O
within	O
a	O
guarded	O
sandbox	O
.	O
</s>
<s>
Digital	O
certificates	O
are	O
issued	O
by	O
certificate	B-Architecture
authorities	I-Architecture
.	O
</s>
<s>
The	O
APIs	B-General_Concept
in	O
java.beans	O
are	O
intended	O
for	O
use	O
by	O
a	O
bean	O
editing	O
tool	O
,	O
in	O
which	O
beans	O
can	O
be	O
combined	O
,	O
customized	O
,	O
and	O
manipulated	O
.	O
</s>
<s>
One	O
type	O
of	O
bean	O
editor	O
is	O
a	O
GUI	B-Application
designer	O
in	O
an	O
integrated	B-Application
development	I-Application
environment	I-Application
.	O
</s>
<s>
The	O
,	O
or	O
Abstract	O
Window	O
Toolkit	O
,	O
provides	O
access	O
to	O
a	O
basic	O
set	O
of	O
GUI	B-Application
widgets	O
based	O
on	O
the	O
underlying	O
native	O
platform	O
's	O
widget	B-Library
set	I-Library
,	O
the	O
core	O
of	O
the	O
GUI	B-Application
event	O
subsystem	O
,	O
and	O
the	O
interface	O
between	O
the	O
native	O
windowing	O
system	O
and	O
the	O
Java	B-Language
application	O
.	O
</s>
<s>
It	O
also	O
provides	O
several	O
basic	O
layout	B-Library
managers	I-Library
,	O
a	O
datatransfer	O
package	O
for	O
use	O
with	O
the	O
Clipboard	O
and	O
Drag	O
and	O
Drop	O
,	O
the	O
interface	O
to	O
input	B-Device
devices	I-Device
such	O
as	O
mice	B-Device
and	O
keyboards	B-Device
,	O
as	O
well	O
as	O
access	O
to	O
the	O
system	O
tray	O
on	O
supporting	O
systems	O
.	O
</s>
<s>
This	O
package	O
,	O
along	O
with	O
javax.swing	B-Language
contains	O
the	O
largest	O
number	O
of	O
enums	B-Language
(	O
7	O
in	O
all	O
)	O
in	O
JDK	B-Language
6	O
.	O
</s>
<s>
The	O
package	O
provides	O
Java	B-Language
remote	I-Language
method	I-Language
invocation	I-Language
to	O
support	O
remote	B-Operating_System
procedure	I-Operating_System
calls	I-Operating_System
between	O
two	O
java	B-Language
applications	O
running	O
in	O
different	O
JVMs	B-Language
.	O
</s>
<s>
An	O
implementation	O
of	O
the	O
JDBC	B-Language
API	B-General_Concept
(	O
used	O
to	O
access	O
SQL	B-Language
databases	I-Language
)	O
is	O
grouped	O
into	O
the	O
package	O
.	O
</s>
<s>
The	O
javax.rmi	O
package	O
provided	O
support	O
for	O
the	O
remote	O
communication	O
between	O
applications	O
,	O
using	O
the	O
RMI	B-Language
over	I-Language
IIOP	I-Language
protocol	O
.	O
</s>
<s>
This	O
protocol	O
combines	O
RMI	B-Language
and	O
CORBA	B-Architecture
features	O
.	O
</s>
<s>
Swing	B-Language
is	O
a	O
collection	O
of	O
routines	O
that	O
build	O
on	O
java.awt	O
to	O
provide	O
a	O
platform	O
independent	O
widget	B-Library
toolkit	I-Library
.	O
</s>
<s>
uses	O
the	O
2D	O
drawing	O
routines	O
to	O
render	O
the	O
user	O
interface	O
components	O
instead	O
of	O
relying	O
on	O
the	O
underlying	O
native	O
operating	B-General_Concept
system	I-General_Concept
GUI	B-Application
support	O
.	O
</s>
<s>
This	O
package	O
contains	O
the	O
largest	O
number	O
of	O
classes	O
(	O
133	O
in	O
all	O
)	O
in	O
JDK	B-Language
6	O
.	O
</s>
<s>
This	O
package	O
,	O
along	O
with	O
java.awt	O
also	O
contains	O
the	O
largest	O
number	O
of	O
enums	B-Language
(	O
7	O
in	O
all	O
)	O
in	O
JDK	B-Language
6	O
.	O
</s>
<s>
It	O
supports	O
pluggable	O
looks	O
and	O
feels	O
(	O
PLAFs	O
)	O
so	O
that	O
widgets	O
in	O
the	O
GUI	B-Application
can	O
imitate	O
those	O
from	O
the	O
underlying	O
native	O
system	O
.	O
</s>
<s>
Design	O
patterns	O
permeate	O
the	O
system	O
,	O
especially	O
a	O
modification	O
of	O
the	O
model	O
–	O
view	O
–	O
controller	O
pattern	O
,	O
which	O
loosens	O
the	O
coupling	B-Application
between	O
function	O
and	O
appearance	O
.	O
</s>
<s>
One	O
inconsistency	O
is	O
that	O
(	O
as	O
of	O
J2SE	B-Language
1.3	O
)	O
fonts	O
are	O
drawn	O
by	O
the	O
underlying	O
native	O
system	O
,	O
and	O
not	O
by	O
Java	B-Language
,	O
limiting	O
text	O
portability	O
.	O
</s>
<s>
In	O
general	O
,	O
"	O
layouts	O
"	O
are	O
used	O
and	O
keep	O
elements	O
within	O
an	O
aesthetically	O
consistent	O
GUI	B-Application
across	O
platforms	B-Device
.	O
</s>
<s>
The	O
javax.xml.bind.annotation	O
package	O
contained	O
the	O
largest	O
number	O
of	O
Annotation	O
Types	O
(	O
30	O
in	O
all	O
)	O
in	O
JDK	B-Language
6	O
.	O
</s>
<s>
It	O
defines	O
annotations	O
for	O
customizing	O
Java	B-Language
program	O
elements	O
to	O
XML	O
Schema	O
mapping	O
.	O
</s>
<s>
The	O
org.omg.CORBA	O
package	O
provided	O
support	O
for	O
the	O
remote	O
communication	O
between	O
applications	O
using	O
the	O
General	B-Operating_System
Inter-ORB	I-Operating_System
Protocol	I-Operating_System
and	O
supports	O
other	O
features	O
of	O
the	O
common	B-Architecture
object	I-Architecture
request	I-Architecture
broker	I-Architecture
architecture	I-Architecture
.	O
</s>
<s>
Same	O
as	O
RMI	B-Language
and	O
RMI-IIOP	B-Language
,	O
this	O
package	O
is	O
for	O
calling	O
remote	O
methods	O
of	O
objects	O
on	O
other	O
virtual	O
machines	O
(	O
usually	O
via	O
network	O
)	O
.	O
</s>
<s>
This	O
package	O
contained	O
the	O
largest	O
number	O
of	O
Exception	O
classes	O
(	O
45	O
in	O
all	O
)	O
in	O
JDK	B-Language
6	O
.	O
</s>
<s>
From	O
all	O
communication	O
possibilities	O
CORBA	B-Architecture
is	O
portable	O
between	O
various	O
languages	O
;	O
however	O
,	O
with	O
this	O
comes	O
more	O
complexity	O
.	O
</s>
<s>
These	O
packages	O
were	O
deprecated	O
in	O
Java	B-Language
9	O
and	O
removed	O
from	O
Java	B-Language
11	O
.	O
</s>
<s>
The	O
org.omg.PortableInterceptor	O
package	O
contained	O
the	O
largest	O
number	O
of	O
interfaces	B-Language
(	O
39	O
in	O
all	O
)	O
in	O
JDK	B-Language
6	O
.	O
</s>
<s>
Security	O
alerts	O
from	O
Oracle	B-Application
announce	O
critical	O
security-related	O
patches	O
to	O
Java	B-Language
SE	I-Language
.	O
</s>
