<s>
Simple	B-Language
Logging	I-Language
Facade	I-Language
for	I-Language
Java	I-Language
(	O
SLF4J	B-Language
)	O
provides	O
a	O
Java	B-Language
logging	O
API	B-General_Concept
by	O
means	O
of	O
a	O
simple	O
facade	O
pattern	O
.	O
</s>
<s>
The	O
underlying	O
logging	O
backend	O
is	O
determined	O
at	B-Library
runtime	I-Library
by	O
adding	O
the	O
desired	O
binding	O
to	O
the	O
classpath	B-Language
and	O
may	O
be	O
the	O
standard	O
Sun	O
Java	B-Language
logging	O
package	O
java.util.logging	O
,	O
Log4j	B-Application
,	O
Reload4j	B-Application
,	O
Logback	O
or	O
tinylog	O
.	O
</s>
<s>
The	O
separation	O
of	O
the	O
client	O
API	B-General_Concept
from	O
the	O
logging	O
backend	O
reduces	O
the	O
coupling	O
between	O
an	O
application	O
and	O
any	O
particular	O
logging	O
framework	O
.	O
</s>
<s>
SLF4J	B-Language
was	O
created	O
by	O
Ceki	O
Gülcü	O
as	O
a	O
more	O
reliable	O
alternative	O
to	O
Jakarta	O
Commons	O
Logging	O
framework	O
.	O
</s>
<s>
Research	O
in	O
2013	O
on	O
10,000	O
GitHub	O
projects	O
found	O
that	O
the	O
most	O
popular	O
Java	B-Language
library	O
is	O
SLF4J	B-Language
,	O
along	O
with	O
JUnit	B-Language
,	O
with	O
30.7	O
%	O
of	O
projects	O
using	O
it	O
.	O
</s>
<s>
Five	O
of	O
log4j	B-Application
's	O
six	O
logging	O
levels	O
are	O
used	O
(	O
ERROR	O
,	O
WARN	O
,	O
INFO	O
,	O
DEBUG	O
,	O
TRACE	O
)	O
.	O
</s>
<s>
In	O
addition	O
,	O
SLF4J	B-Language
markers	O
offer	O
a	O
more	O
general	O
method	O
for	O
tagging	O
log	O
statements	O
.	O
</s>
<s>
Logger	O
instances	O
are	O
created	O
via	O
the	O
LoggerFactory	O
,	O
which	O
is	O
very	O
similar	O
in	O
log4j	B-Application
.	O
</s>
<s>
In	O
Logger	O
,	O
the	O
logging	O
methods	O
are	O
overloaded	B-Language
with	O
forms	O
that	O
accept	O
one	O
,	O
two	O
or	O
more	O
values	O
.	O
</s>
<s>
This	O
is	O
simple	O
to	O
use	O
yet	O
provides	O
a	O
performance	O
benefit	O
when	O
the	O
values	O
have	O
expensive	O
toString( )	O
methods	O
.	O
</s>
<s>
In	O
the	O
following	O
example	O
,	O
string	O
concatenation	O
and	O
toString( )	O
method	O
for	O
the	O
values	O
count	O
or	O
userAccountList	O
are	O
performed	O
only	O
when	O
DEBUG	O
is	O
enabled	O
.	O
</s>
<s>
Unlike	O
log4j	B-Application
,	O
SLF4J	B-Language
offers	O
logging	O
methods	O
that	O
accept	O
markers	O
.	O
</s>
<s>
Apache	O
log4j	B-Application
2.x	O
supports	O
all	O
slf4j	B-Language
features	O
.	O
</s>
<s>
Requires	O
Java	B-Language
8	O
or	O
later	O
.	O
</s>
<s>
Version	O
2.0.0	O
adds	O
support	O
for	O
lambda	O
syntax	O
and	O
uses	O
a	O
Fluent	O
API	B-General_Concept
.	O
</s>
<s>
Fluent	O
API	B-General_Concept
.	O
</s>
<s>
Version	O
1.7.35	O
slf4j-log4j12	O
module	O
is	O
replaced	O
by	O
slf4j-reload4j	O
.	O
</s>
<s>
Version	O
1.7.33	O
adds	O
support	O
for	O
reload4j	B-Application
via	O
the	O
slf4j-reload4j	O
module	O
.	O
</s>
<s>
Version	O
1.7.0	O
added	O
support	O
for	O
,	O
requiring	O
support	O
for	O
Java	B-Language
5	O
or	O
later	O
.	O
</s>
<s>
Version	O
1.6	O
brought	O
a	O
no-operation	B-Language
implementation	O
used	O
by	O
default	O
if	O
no	O
binding	O
found	O
.	O
</s>
