actionfilter.java

Jodd是一个开源的公用Java基础类库

package jodd.servlet;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

/**
 * ActionFilter implementation is used by ActionController. It intercepts all
 * actions, so filter will be called before and after the action invokation.
 * <p>
 *
 * Filter also may chnage the default behaviour of the mapped action.
 * Therefore, it may be used for managing security access in the application etc.
 *
 * @author Weird
 */
public interface ActionFilter {

	/**
	 * Called BEFORE some action is invoked. It may return <code>null</code> for letting the
	 * Controller to invoke the mapped action or it may return a forward instead of action.
	 *
	 * @param request  http request
	 * @param response http response
	 * @param action   action class that is going to be invoked
	 *
	 * @return null for invoking the action, otherwise the forward string
	 */
	public String onAction(HttpServletRequest request, HttpServletResponse response, ActionServlet action);


	/**
	 * Called AFTER some action is invoked. It may return <code>null</code> for letting the
	 * Controller to process the returned results of the action or it may return a
	 * forward string that will be override returned results.
	 *
	 * @param request  http request
	 * @param response http response
	 * @param action   action class that is going to be invoked
	 * @param actionResult
	 *                 result of invoked method
	 *
	 * @return not-null for overrinding returned action result
	 */
	public String onAfterAction(HttpServletRequest request, HttpServletResponse response, ActionServlet action, String actionResult);

}