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By definition, every ActionForm must be a subclass of org.apache.struts.action.ActionForm, which implements java.io.Serializable. In order to avoid an Eclipse warning, your ActionForm can declare a static final serialVersionUID field of type long (e.g., private static final long serialVersionUID = 1L
) but this is not mandatory. Some developers dislike the fact that Eclipse warns us if we don't declare serialVersionUID. Others think it is best to always declare it.
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