Struts2-如何在页面加载时调用prepare（）方法？

Question

I want to invoke the prepare() method when a page loads in Struts 2.

It is my understanding that if I implement the Preparable interface on my action that the prepare() method should automatically fire when the page loads. Is this correct? Or is there any other configuration required?

I ask because this is what I have done and the prepare method only fires upon a button click, just before the execute method fires.

I want the prepare method to fire just after/before the page loads to populate an attribute on the action. How can I do this?

Answer 1

prepare() executes when a Preparable action is executed.

If it's not firing, then your prepare() method is either in the wrong action, you're not accessing the page through an action initially (eg, hitting a plain JSP), or there's an interceptor stack configuration issue.

Answer 2

It is my understanding that if I implement the Preparable interface on my action that the prepare() method should automatically fire when the page loads.

As per my understanding this is not correct . The prepare method is used to prepare some data to be used by the execute() method or any other worker method of the Action class and is thus called just before the worker method on the request from the Browser.

Invoking the prepare() method on page load would be programatically cumbersome and thus should be avoided. Try setting the attribute in other way

Hope this helps :)