CODEWITHSUNDEEP
javadynamicpropertieslog4j
Metalhead89
Metalhead89

Reputation: 1910

Log4J change File path dynamically

I want to change the path and file name of my log4j logfile dynamically.

I have read a lot of pages and nearly every tell me that I should use system properties like here: how to change the log4j log file dynamically?

So my log4j.properties file looks like this:

log4j.logger.JDBC_LOGGER=INFO,jdbcTests
log4j.additivity.JDBC_LOGGER = false

log4j.appender.jdbcTests=org.apache.log4j.FileAppender
log4j.appender.jdbcTests.File=${my.log}
log4j.appender.jdbcTests.layout=org.apache.log4j.PatternLayout
log4j.appender.jdbcTests.append = false
log4j.appender.jdbcTests.layout.ConversionPattern=%d{yyyy mm dd HH:mm:ss} %5p %C:Line %L - %m%n

In my main method I am going to set my new system property:

System.setProperty("{my.log", "C:/logfile.log");

But I just get an error:

log4j:ERROR setFile(null,false) call failed.
java.io.FileNotFoundException: 
    at java.io.FileOutputStream.open(Native Method)....

And when I try to read my set system property with:

System.out.println(System.getProperty("my.log"));

it return null. What do I do wrong?

Upvotes: 13

Views: 41684

Answers (3)

Niket
Niket

Reputation: 1

Just set property before instantiating logger, once you initilize the logger setting the property will not worth. just like below:

System.setProperty("my.log", "C:\\src\\com\\web\\automation\\logs\\Application.log");
PP_LOGS = Logger.getLogger("devpinoyLogger");

Upvotes: 0

IllegalArgumentException
IllegalArgumentException

Reputation: 680

You have a misspelling: "{my.log" instead of "my.log"

Upvotes: 1

Peter Lawrey
Peter Lawrey

Reputation: 533432

I think you meant "my.log" not "{my.log"

System.setProperty("my.log", "C:/logfile.log");

I wouldn't imagine you can change this once the logging has started so you need to set this as early in your program as possible.

BTW: You can sub-class FileAppender to make it behave any way you like.

Upvotes: 9

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