java - Exception thrown while using logback/slf4j

Question

I am using slf4j 1.6.2 api jar (tried using 1.6.1 as well) - logback version is 0.9.29 (core & classic). I am using jdk1.6 on ubuntu. The exception I received is copied below.

Exception in thread "main" java.lang.NoSuchMethodError: org.slf4j.helpers.MessageFormatter.arrayFormat(Ljava/lang/String;[Ljava/lang/Object;)Lorg/slf4j/helpers/FormattingTuple;
    at ch.qos.logback.classic.spi.LoggingEvent.<init>(LoggingEvent.java:112)
    at ch.qos.logback.classic.Logger.buildLoggingEventAndAppend(Logger.java:471)
    at ch.qos.logback.classic.Logger.filterAndLog_0_Or3Plus(Logger.java:427)
    at ch.qos.logback.classic.Logger.info(Logger.java:631)

I am also getting a message complaining about slf4j binding mismatch.

"SLF4J: The requested version 1.6 by your slf4j binding is not compatible with [1.5.5, 1.5.6, 1.5.7, 1.5.8, 1.5.9, 1.5.10, 1.5.11]"

Answer 1

It very much looks like the version of slf4j-api.jar being loaded by the JVM has version 1.5.x. You surely have slf4j-api-1.5.x.jar on your class path (in addition to slf4j-api-1.6.2.jar). Check your class path.