<s>
The	O
Java	B-Language
Platform	I-Language
Module	I-Language
System	I-Language
specifies	O
a	O
distribution	O
format	O
for	O
collections	O
of	O
Java	B-Language
code	I-Language
and	O
associated	O
resources	O
.	O
</s>
<s>
It	O
also	O
specifies	O
a	O
repository	O
for	O
storing	O
these	O
collections	O
,	O
or	O
modules	B-Architecture
,	O
and	O
identifies	O
how	O
they	O
can	O
be	O
discovered	O
,	O
loaded	O
and	O
checked	O
for	O
integrity	O
.	O
</s>
<s>
It	O
includes	O
features	O
such	O
as	O
namespaces	O
with	O
the	O
aim	O
of	O
fixing	O
some	O
of	O
the	O
shortcomings	O
in	O
the	O
existing	O
JAR	B-Language
format	O
,	O
especially	O
the	O
JAR	B-Language
Hell	O
,	O
which	O
can	O
lead	O
to	O
issues	O
such	O
as	O
classpath	B-Language
and	O
class	O
loading	O
problems	O
.	O
</s>
<s>
The	O
Java	B-Language
Module	I-Language
System	I-Language
was	O
initially	O
being	O
developed	O
under	O
the	O
Java	B-Language
Community	I-Language
Process	I-Language
as	O
JSR	B-Language
277	I-Language
and	O
was	O
scheduled	O
to	O
be	O
released	O
with	O
Java	B-Language
7	O
.	O
</s>
<s>
JSR	B-Language
277	I-Language
later	O
was	O
put	O
on	O
hold	O
and	O
Project	O
Jigsaw	O
was	O
created	O
to	O
modularize	O
the	O
JDK	O
.	O
</s>
<s>
This	O
JSR	O
was	O
superseded	O
by	O
JSR	O
376	O
(	O
Java	B-Language
Platform	I-Language
Module	I-Language
System	I-Language
)	O
.	O
</s>
<s>
Project	O
Jigsaw	O
was	O
originally	O
intended	O
for	O
Java	B-Language
7	O
(	O
2011	O
)	O
but	O
was	O
deferred	O
to	O
Java	B-Language
8	O
(	O
2014	O
)	O
as	O
part	O
of	O
Plan	O
B	O
,	O
and	O
again	O
deferred	O
to	O
a	O
Java	B-Language
9	O
release	O
in	O
2017	O
.	O
</s>
<s>
Java	B-Language
9	O
including	O
the	O
Java	B-Language
Module	I-Language
System	I-Language
was	O
released	O
on	O
September	O
21	O
,	O
2017	O
.	O
</s>
<s>
The	O
Java	B-Language
Module	I-Language
System	I-Language
implemented	O
in	O
Java	B-Language
9	O
includes	O
the	O
following	O
JEPs	O
and	O
JSR	O
(	O
Java	B-Language
Specification	I-Language
Request	I-Language
)	O
:	O
</s>
<s>
Additionally	O
,	O
several	O
other	O
JDK	O
9	O
features	O
have	O
been	O
added	O
to	O
ease	O
transition	O
to	O
the	O
module	B-Architecture
system	I-Architecture
:	O
</s>
<s>
JEP	B-Language
238	O
:	O
Multi-Release	O
JAR	B-Language
Files	I-Language
:	O
Extend	O
the	O
JAR	B-Language
file	I-Language
format	I-Language
to	O
allow	O
multiple	O
,	O
Java-release-specific	O
versions	O
of	O
class	O
files	O
to	O
coexist	O
in	O
a	O
single	O
archive	O
.	O
</s>
<s>
JEP	B-Language
253	O
:	O
Prepare	O
JavaFX	B-Application
UI	O
Controls	O
&	O
CSS	O
APIs	O
for	O
Modularization	O
:	O
Define	O
public	O
APIs	O
for	O
the	O
JavaFX	B-Application
functionalities	O
that	O
is	O
presently	O
only	O
available	O
via	O
internal	O
APIs	O
and	O
would	O
become	O
inaccessible	O
due	O
to	O
modularization	O
.	O
</s>
<s>
JEP	B-Language
260	O
:	O
Encapsulate	O
Most	O
Internal	O
APIs	O
:	O
Make	O
most	O
of	O
the	O
JDK	O
's	O
internal	O
APIs	O
inaccessible	O
by	O
default	O
but	O
leave	O
a	O
few	O
critical	O
,	O
widely-used	O
internal	O
APIs	O
accessible	O
,	O
until	O
supported	O
replacements	O
exist	O
for	O
all	O
or	O
most	O
of	O
their	O
functionality	O
.	O
</s>
<s>
JEP	B-Language
275	O
:	O
Modular	B-Architecture
Java	B-Language
Application	O
Packaging	O
:	O
The	O
Java	B-Language
packager	I-Language
will	O
evolve	O
for	O
JDK	O
9	O
,	O
making	O
it	O
aware	O
of	O
modules	B-Architecture
,	O
allowing	O
for	O
example	O
to	O
package	O
a	O
module	B-Architecture
and	O
all	O
the	O
modules	B-Architecture
it	O
depends	O
on	O
.	O
</s>
<s>
Modules	B-Architecture
are	O
a	O
new	O
way	O
of	O
grouping	O
code	O
.	O
</s>
<s>
Contrary	O
to	O
Jar	B-Language
files	I-Language
,	O
modules	B-Architecture
explicitly	O
declare	O
which	O
modules	B-Architecture
they	O
depend	O
on	O
,	O
and	O
what	O
packages	O
they	O
export	O
.	O
</s>
<s>
The	O
module	B-Architecture
declaration	O
is	O
placed	O
in	O
a	O
file	O
named	O
module-info.java	O
at	O
the	O
root	O
of	O
the	O
module	B-Architecture
’s	O
source-file	O
hierarchy	O
.	O
</s>
<s>
The	O
JDK	O
will	O
verify	O
dependencies	O
and	O
interactions	O
between	O
modules	B-Architecture
both	O
at	O
compile-time	O
and	O
runtime	O
.	O
</s>
<s>
For	O
example	O
,	O
the	O
following	O
module	B-Architecture
declaration	O
declares	O
that	O
the	O
module	B-Architecture
com.foo.bar	O
depends	O
on	O
another	O
com.foo.baz	O
module	B-Architecture
,	O
and	O
exports	O
the	O
following	O
packages	O
:	O
com.foo.bar.alpha	O
and	O
com.foo.bar.beta	O
:	O
</s>
<s>
The	O
public	O
members	O
of	O
com.foo.bar.alpha	O
and	O
com.foo.bar.beta	O
packages	O
will	O
be	O
accessible	O
by	O
dependent	O
modules	B-Architecture
.	O
</s>
<s>
Private	O
members	O
are	O
inaccessible	O
even	O
through	O
a	O
means	O
such	O
as	O
reflection	B-Language
.	O
</s>
<s>
Note	O
that	O
in	O
Java	B-Language
versions	O
9	O
through	O
16	O
,	O
whether	O
such	O
'	O
illegal	O
access	O
 '	O
is	O
de	O
facto	O
permitted	O
depends	O
on	O
a	O
command	O
line	O
setting	O
.	O
</s>
<s>
The	O
JDK	O
itself	O
has	O
been	O
modularized	O
in	O
Java	B-Language
9	O
.	O
</s>
<s>
The	O
Java	B-Language
Module	I-Language
System	I-Language
does	O
not	O
intend	O
to	O
support	O
all	O
the	O
functionalities	O
that	O
the	O
OSGi	B-Application
platform	O
currently	O
supports	O
(	O
for	O
example	O
the	O
Life-Cycle	O
model	O
and	O
the	O
Services	O
Registry	O
)	O
.	O
</s>
<s>
However	O
the	O
Java	B-Language
Module	I-Language
System	I-Language
will	O
support	O
functions	O
which	O
are	O
not	O
supported	O
by	O
OSGi	B-Application
,	O
such	O
as	O
modularity	B-Architecture
at	O
compile-time	O
,	O
and	O
built-in	O
support	O
for	O
native	O
libraries	O
.	O
</s>
<s>
A	O
couple	O
of	O
articles	O
exploring	O
how	O
the	O
Java	B-Language
Module	I-Language
System	I-Language
and	O
OSGi	B-Application
could	O
interoperate	O
were	O
published	O
in	O
2016	O
.	O
</s>
<s>
These	O
can	O
be	O
found	O
on	O
InfoQ	O
and	O
also	O
the	O
OSGi	B-Application
Alliance	I-Application
Blog	O
.	O
</s>
