Java examples for Native OS:Log
Use the unified JVM logger in Java 9.
To initiate the logging, execute the following statement:
java -Xlog:all:file=test.txt:time,level
The statement will configure the JVM to log all tags to a file named test.txt.
The following command uses 'gc' using 'trace' level to stdout using the 'uptime' decoration.
java -Xlog:gc=trace:uptime
There are several options available for the -Xlog flag that indicate "what" to log, and "where" to log in the following format:
-Xlog[:option=<what:level>:<output>:<decorators>:<output-options>]
The following table list Xlog Decorators.
| Decorator | Description |
|---|---|
| Time | Current time and date (ISO-8601) |
| Uptime | Amount of time surpassed since the start of the JVM (seconds and milliseconds) |
| Timemillis | System.currentTimeMillis() output |
| Uptimemillis | Milliseconds surpassed since the start of the JVM |
| Timenanos | System.nanoTime() output |
| Uptimenanos | Nanoseconds surpassed since the start of the JVM |
| Pid | Process identifier |
| Tid | Thread identifier |
| Level | Associated log message level |
| Tags | Associated log message tag |
The possible output options include:
filecount=<file count> filesize=<file size in kb> parameter=value