spring mvc list

我使用这样无法传入

@requestMapping("/test")
public String getTest(List<User> users){
    return "test";
}

我们直接写List是会报错的，因为springmvc不知道怎么初始化list对象，因此它是会报错的

org.springframework.beans.BeanInstantiationException: Could not instantiate bean class [java.util.List]: Specified class is an interface
	at org.springframework.beans.BeanUtils.instantiateClass(BeanUtils.java:102)
	at org.springframework.web.method.annotation.ModelAttributeMethodProcessor.createAttribute(ModelAttributeMethodProcessor.java:138)
	at org.springframework.web.servlet.mvc.method.annotation.ServletModelAttributeMethodProcessor.createAttribute(ServletModelAttributeMethodProcessor.java:81)
	at org.springframework.web.method.annotation.ModelAttributeMethodProcessor.resolveArgument(ModelAttributeMethodProcessor.java:104)
	at org.springframework.web.method.support.HandlerMethodArgumentResolverComposite.resolveArgument(HandlerMethodArgumentResolverComposite.java:79)
	at org.springframework.web.method.support.InvocableHandlerMethod.getMethodArgumentValues(InvocableHandlerMethod.java:157)
	at org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:124)
	at org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:104)
	at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandleMethod(RequestMappingHandlerAdapter.java:748)
	at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:684)
	at org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:83)

这个时候可以借助加一层模型，因为第一层（方法参数），是直接调用class的实例化来初始化的。

E{
  List<F> flist;
  getter/setter;
}

Controller{

  public execute(E e){
    List<F> list = e.getFlist();   ---
  }

}

另外可以改用数组，比如

Controller{

  public execute(String[] es){
  
  }

}

或者直接用list的子类

@RequestMapping(value = "/classify/listTreeAndSelect.html")
	public void listAndSelect(HttpServletRequest request, ModelMap model,
			UnifiedUser user,ArrayList<Long> selectIds) {
		
	}