Log4j IOStreams
Log4j IOStreams
The IOStreams component is a
Log4j API
extension that provides numerous classes from
java.io
that can either write to a
Logger
while writing to another OutputStream
or Writer
, or the contents read by an InputStream
or Reader
can be
wiretapped
by a Logger
.
Requirements
The Log4j IOStreams API extension requires the Log4j 2 API. This component was introduced in Log4j 2.1.
Usage
The main entry point for the IOStreams module is the builder class IoBuilder
, and in particular, the IoBuilder.forLogger()
methods.
One primary usage of this API extension is for setting up loggers in the JDBC API.
For example:
PrintWriter logger = IoBuilder.forLogger(DriverManager.class)
.setLevel(Level.DEBUG)
.buildPrintWriter();
DriverManager.setLogWriter(logger);
Using the IoBuilder
class, there are a few more options that can be set.
In general, there are six primary classes one can build from it: Reader
, Writer
, PrintWriter
, InputStream
, OutputStream
, and PrintStream
.
The input-oriented classes are for wiretapping, and the output-oriented classes are for creating either an output class that solely outputs its lines as log messages, or an output filter class that logs all lines output through it to its delegate output class.