Adjust Logging level for apache commons logging?

Question

I have a simple console app which uses apache's PDFBox library, which in turn uses commons logging. I'm getting a lot of junk messages in my console which I'd like to suppress:

Feb 15, 2011 3:56:40 PM org.apache.pdfbox.util.PDFStreamEngine processOperator INFO: unsupported/disabled operation: EI

In my code, I've tried to reset the log levels to no avail:

Logger.getLogger("org.apache.pdfbox.util.PDFStreamEngine").setLevel(Level.OFF);
Logger.getLogger("org.apache.pdfbox.util").setLevel(Level.OFF);
Logger.getLogger("org.apache.pdfbox").setLevel(Level.OFF);

Despite these settings, the messages are still showing up on the console. Retrieving the log object from Commons logging doesn't help either, since it doesn't seem to have a way to set the level.

Is there a way to suppress these messages programmatically? Or do I need to add a config file?

Answer 1

Commons-logging is only a logging-facade, meaning it doesn't provide the code which actually writes the logdata to eg, disk. What you need to change is the configuration for the actual logging implementation (such as logback , log4j , sl4fj etc). If no such library is found it defaults to java.util.logging .

I would recommend putting eg, log4j in the classpath and add a log4j.xml configuration file in your classpath. The mere presence of log4j in the classpath is in this case enough to initialize it. Log4j can also be configured programmatically .

Answer 2

This works for me:

String[] loggers = { "org.apache.pdfbox.util.PDFStreamEngine",
        "org.apache.pdfbox.pdmodel.font.PDSimpleFont" };
for (String logger : loggers) {
  org.apache.log4j.Logger logpdfengine = org.apache.log4j.Logger
         .getLogger(logger);
  logpdfengine.setLevel(org.apache.log4j.Level.OFF);
}

Answer 3

In case you have no time to figure out which Logging implementation is used underneath by the Apache commons-logging, try to disable all that are in you classpath. Following code tests three implementations.

If any of the lines doesn't compile, do not add the dependency! Just remove the line.

String[] loggers = { "org.apache.pdfbox.util.PDFStreamEngine",
    "org.apache.pdfbox.pdmodel.font.PDSimpleFont", "httpclient.wire.header" , "httpclient.wire.content"
for (String ln : names) {
  // Try java.util.logging as backend
  java.util.logging.Logger.getLogger(ln).setLevel(java.util.logging.Level.WARNING);

  // Try Log4J as backend
  org.apache.log4j.Logger.getLogger(ln).setLevel(org.apache.log4j.Level.WARN);

  // Try another backend
  Log4JLoggerFactory.getInstance().getLogger(ln).setLevel(java.util.logging.Level.WARNING);
 }

Answer 4

Apache commons-logging使用下面的一些其他日志框架（ java.util.logging或Log4J），你必须调查它在你的项目中使用哪一个并在那里设置适当的日志记录级别。