Hi

I am using log4j in a webapp and it works fine except that I cant seem to log a stack trace: I would like to do someting like:

try {
blah blah
}
catch(Exception e) {
logger.error("Something bad happened: " + e.printStackTrace());
}

Obviously that will not work - but that's the kind of thing I want to do. I guess ideally it would be nice to pass the logger as a PrintStream argument e.g. printStackTrace(logger) but log4j's Logger class doesn't lend itself to this.

The only thing I can think is just to pass exception's 'message' to a standard log call, but this will not give me nearly as much info as the stack trace.

Any suggestions would be great

thanks

 

 

Start by reading the javadoc?

logger.<level>( "this is a message", aThrowable );

 

 

I wrote a class ExceptionUtil to do this:

public class ExceptionUtil
{
    public static String getStackTrace(Throwable t) {
        StringWriter sw = new StringWriter();
        PrintWriter pw = new PrintWriter(sw);
        t.printStackTrace(pw);
        pw.flush();
        return sw.toString();
    }
}

Use it like this:

try {
    // ...code that throws exception...
}
catch (Exception e) {
    logger.warn("Error while doing something: " + ExceptionUtil.getStackTrace(e));
}

Jesper

 

 

Is there any reason why he shouldnt use the method already provided by Log4j?

logger.warn( "whatever", throwable );