@Test
    public void test2() {
        Integer i1 = Integer.valueOf(1);
        Integer i2 = Integer.valueOf(2);
        Integer i3 = Integer.valueOf(3);
        Exception e = new Exception("This is a test exception.");
        Logger logger = LoggerFactory.getLogger("test2");

        logger.debug("Hello world 1.");
        logger.debug("Hello world {}", i1);
        logger.debug("val={} val={}", i1, i2);
        logger.debug("val={} val={} val={}", new Object[] { i1, i2, i3 });

        logger.debug("Hello world 2", e);
        logger.info("Hello world 2.");

        logger.warn("Hello world 3.");
        logger.warn("Hello world 3", e);

        logger.error("Hello world 4.");
        logger.error("Hello world {}", Integer.valueOf(3));
        logger.error("Hello world 4.", e);
    }
Test whether invoking the SLF4J API causes problems or not.

@author Ceki Gulcu
slf4j-simple/src/test/java/org/slf4j/simple/InvocationTest.java