package com.opensymphony.xwork2.interceptor;import com.opensymphony.xwork2.ActionInvocation;import java.io.Serializable;public interface Interceptor extends Serializable {    /**     * Called to let an interceptor clean up any resources it has allocated.     */    void destroy();    /**     * Called after an interceptor is created, but before any requests are processed using     * {@link #intercept(com.opensymphony.xwork2.ActionInvocation) intercept} , giving     * the Interceptor a chance to initialize any needed resources.     */    void init();    /**     * Allows the Interceptor to do some processing on the request before and/or after the rest of the processing of the     * request by the {@link ActionInvocation} or to short-circuit the processing and just return a String return code.     *     * @param invocation the action invocation     * @return the return code, either returned from {@link ActionInvocation#invoke()}, or from the interceptor itself.     * @throws Exception any system-level error, as defined in {@link com.opensymphony.xwork2.Action#execute()}.     */    String intercept(ActionInvocation invocation) throws Exception;}