play framework 传参的问题

Question

public static void showDocByCategory(String categoryName) {
		List<DocData> docList = DocData.find("byDOCUMENT_CATEGORY", categoryName).fetch();
		showDoc(docList);
	}
	
public static void showDoc(List docList) {
	if(docList != null) {
		render(docList);
	}
}

play.exceptions.UnexpectedException: Unexpected Error
	at play.mvc.Controller.redirect(Controller.java:612)
	at play.mvc.Controller.redirect(Controller.java:542)
	at controllers.WizController.showDoc(WizController.java)
	at controllers.WizController.showDocByTag(WizController.java:43)
	at play.mvc.ActionInvoker.invokeWithContinuation(ActionInvoker.java:546)
	at play.mvc.ActionInvoker.invoke(ActionInvoker.java:500)
	at play.mvc.ActionInvoker.invokeControllerMethod(ActionInvoker.java:476)
	at play.mvc.ActionInvoker.invokeControllerMethod(ActionInvoker.java:471)
	at play.mvc.ActionInvoker.invoke(ActionInvoker.java:159)
	at Invocation.HTTP Request(Play!)
Caused by: java.lang.ClassCastException: java.lang.String cannot be cast to java.util.List
	at play.data.binding.Unbinder.unBind(Unbinder.java:44)
	at play.data.binding.Unbinder.unBind(Unbinder.java:110)
	at play.data.binding.Unbinder.unBind(Unbinder.java:63)
	at play.data.binding.Unbinder.unBind(Unbinder.java:29)
	at play.mvc.Controller.redirect(Controller.java:577)
	... 9 more

Answer 1

了解了，谢谢：）

Answer 2

目前，据我所知的，List的绑定，只支持基本类型的包装类型和String类型，自定义类型是绑不了的。

Answer 3

为什么传递list参数就会报这样的错呢，求大神指点下