Why is System.out.println bad?

Question

When i run my PMD plugin they say System.out.println has been used. why is System.out.println bad to use and is it a defect when using PMD plugin? and what is the alternative way of over coming this?

Answer 1

System.out.println..

are usually intended for debugging purposes and can remain in the codebase even in production code. By using a logger one can enable/disable this behaviour at will (and by priority) and avoid clogging the Standard out log.

^{(from SourceMeter Java user guide under "Java Logging Rules")}

Import needed (.jar)

Logger site

Example:

import org.apache.log4j.Logger;

class Foo{
    private static final Logger LOG = Logger.getLogger(Foo.class);
    public void testA () {
        System.out.println("Entering test");
        // Better use this
        LOG.info("Entering test");
    }
}