question: public static void loggerInit ( Level level , boolean isRedirectStdOutErr , String format ) throws IOException { setLoggingFormat ( format ) ; Logger rootLogger = Logger . getLogger ( "" ) ; for ( Handler handler : rootLogger . getHandlers ( ) ) { handler . setLevel ( level ) ; } rootLogger . setLevel ( level ) ; if ( isRedirectStdOutErr ) { for ( Handler handler : rootLogger . getHandlers ( ) ) { if ( handler instanceof ConsoleHandler ) { rootLogger . removeHandler ( handler ) ; } } Logger logger ; LoggingOutputStream los ; logger = Logger . getLogger ( "stdout" ) ; los = new LoggingOutputStream ( logger , StdOutErrLevel . STDOUT ) ; System . setOut ( new PrintStream ( los , true ) ) ; logger = Logger . getLogger ( "stderr" ) ; los = new LoggingOutputStream ( logger , StdOutErrLevel . STDERR ) ; System . setErr ( new PrintStream ( los , true ) ) ; } }
target:  Init java util logging