Struts2 18 Interceptor (13th)

MultiselectInterceptor the interceptor processes the defaultStack 12th position, which is used to process the select tag where no option is selected. The logic of this interceptor is very similar to that of the CheckboxIntercept interceptor, which is almost identical. When no select tag (multiple = "multiple") is selected, the select tag is not selected, which is similar to the checkbox. Because the interceptor is almost the same as the CheckboxInterceptor interceptor, here is a brief introduction: [java] public String intercept (ActionInvocation actionInvocation) throws Exception {Map parameters = actionInvocation. getInvocationContext (). getParameters (); // obtain the request parameter Map <String, Object> newParams = new HashMap <String, Object> (); Set <String> keys = parameters. keySet (); // The key set of Request Parameters for (Iterator <String> iterator = keys. iterator (); iterator. hasNext ();) {String key = iterator. next (); if (key. startsWith ("_ multiselect _") {// determines whether the key is switched to _ multiselect _ String name = key. substring ("_ multiselect _". length (); // remove the current parameter iterator from the request parameter Map. remove (); // if no option is selected, if (! Parameters. containsKey (name) {// Add a String [] with a length of 0 to newParams. put (name, new String [0]) ;}}// add newParams to the request parameter Map parameters. putAll (newParams); // call the next interceptor return actionInvocation. invoke (); <span style = "font-size: 14px" >}</span>