title: when using quartz shcheduler i came accross with NoClassDefFoundErroe
body: <pre><code>public void  HelloSchedule()throws Exception{
  
        SchedulerFactory sf=new StdSchedulerFactory();
        Scheduler sched=sf.getScheduler();
        sched.start();
        JobDetail job = JobBuilder.newJob(Quartzjob.class)
                  .withIdentity("job1", "group1").build();
  
          Trigger trigger = TriggerBuilder.newTrigger().withIdentity("trigger1", "group1")
                  .withSchedule(SimpleScheduleBuilder.simpleSchedule().withIntervalInSeconds(20)
                      .repeatForever()).startNow().build();
  
          sched.scheduleJob(job, trigger);
  
        }
  </code></pre>
  
  <p><strong>Exception</strong></p>
  
  <pre><code> Exception in thread "main" java.lang.NoClassDefFoundError: org/slf4j/LoggerFactory at       org.quartz.impl.StdSchedulerFactory.&lt;init&gt;(StdSchedulerFactory.java:274)
  at quartzSheduler.QuartzTrigger.HelloSchedule(QuartzTrigger.java:28)v
  </code></pre>
  
  <p>i am getting the exception, i have used Quarta-2.1.5.jar , whether i shoud use transaction librarys</p>