What determines where jar files get placed in a war?

Using Eclipse I have imported a WAR with source. I have exported that project as a new war and it ran fine. I then added my own package and exported the war again. The jar file does not show up in /WEB-INF/lib folder. When I deploy the war on a tomcat server it barfs the following error:


Caused by: org.springframework.beans.factory.CannotLoadBeanClassException: Cannot find class [com.sharpline.fields.form.fields.TextAreaFormType] for bean with name 'com.sharpline.fields.form.fields.TextAreaFormType#53c37' defined in ServletContext resource [WEB-INF/activiti-standalone-context.xml]; nested exception is java.lang.ClassNotFoundException: com.sharpline.fields.form.fields.TextAreaFormType
     at org.springframework.beans.factory.support.AbstractBeanFactory.resolveBeanClass(AbstractBeanFactory.java:1262)
     at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:433)
     at org.springframework.beans.factory.support.BeanDefinitionValueResolver.resolveInnerBean(BeanDefinitionValueResolver.java:270)


It looks to me like my class (jar) is missing in the final war. I am new to this and have searched, I just don't quite know what to look for. How do I resolve this?