when im exporting my jar file. i get exporting jar failure and gives me this

Code:
 duplicate entry: org/slf4j/helpers/NOPMDCAdapter.class
  duplicate entry: org/slf4j/helpers/SubstituteLogger.class
  duplicate entry: org/slf4j/helpers/SubstituteLogger.class
  duplicate entry: org/slf4j/helpers/SubstituteLoggerFactory.class
  duplicate entry: org/slf4j/helpers/SubstituteLoggerFactory.class
  duplicate entry: org/slf4j/helpers/Util$1.class
  duplicate entry: org/slf4j/helpers/Util$1.class
  duplicate entry: org/slf4j/helpers/Util$ClassContextSecurityManager.class
  duplicate entry: org/slf4j/helpers/Util$ClassContextSecurityManager.class
  duplicate entry: org/slf4j/helpers/Util.class
  duplicate entry: org/slf4j/helpers/Util.class
  duplicate entry: org/slf4j/ILoggerFactory.class
  duplicate entry: org/slf4j/ILoggerFactory.class
  duplicate entry: org/slf4j/IMarkerFactory.class
  duplicate entry: org/slf4j/IMarkerFactory.class
  duplicate entry: org/slf4j/Logger.class
  duplicate entry: org/slf4j/Logger.class
  duplicate entry: org/slf4j/LoggerFactory.class
  duplicate entry: org/slf4j/LoggerFactory.class
  duplicate entry: org/slf4j/Marker.class
  duplicate entry: org/slf4j/Marker.class
  duplicate entry: org/slf4j/MarkerFactory.class
  duplicate entry: org/slf4j/MarkerFactory.class
  duplicate entry: org/slf4j/MDC$1.class
  duplicate entry: org/slf4j/MDC$1.class
  duplicate entry: org/slf4j/MDC$MDCCloseable.class
  duplicate entry: org/slf4j/MDC$MDCCloseable.class
  duplicate entry: org/slf4j/MDC.class
  duplicate entry: org/slf4j/MDC.class
  duplicate entry: org/slf4j/spi/LocationAwareLogger.class
  duplicate entry: org/slf4j/spi/LocationAwareLogger.class
  duplicate entry: org/slf4j/spi/LoggerFactoryBinder.class
  duplicate entry: org/slf4j/spi/LoggerFactoryBinder.class
  duplicate entry: org/slf4j/spi/MarkerFactoryBinder.class
  duplicate entry: org/slf4j/spi/MarkerFactoryBinder.class
  duplicate entry: org/slf4j/spi/MDCAdapter.class
  duplicate entry: org/slf4j/spi/MDCAdapter.class
theres much more. how do i stop eclipse from doing this.