[출처] :http://stackoverflow.com/questions/16712462/many-commandname-for-one-form-in-spring-mvc
publicclassCombinedCommand(){Activity activity;Etabl etabl;//Getter and setter}

jsp:

<form:form
  action="${pageContext.request.contextPath}/ajouter_activite"
  method="post" commandName="combinedCommand"">...<form:input type="text"path="activity.x"/>...<form:input type="text"path="etabl.y"/>...</form:form>