How do you use the interceptor in Struts2?
How do you use the interceptor in Struts2?
The struts 2 default interceptors are as follows: 1) alias It converts similar parameters that have different names between requests. 3) chain If it is used with chain result type, it makes the properties of previous action available in the current action. 4) checkbox It is used to handle the check boxes in the form.
What is interceptor stack in Struts2?
The interceptor-stack element is used to create an interceptor stack. A stack contains a group of interceptors. Each interceptor in the stack is defined using the interceptor-ref element. In this example we will create a stack similar to the defaultStack and customise the validation interceptor according to our need.
Are interceptors in Struts2 thread safe?
Struts2 interceptors are singleton classes and a new thread is created to handle the request, so it’s not thread safe and we need to implement them carefully to avoid any issues with shared data.
What is the purpose of @action annotation?
1) @Action annotation is used to mark the action class. 2) @Results annotation is used to define multiple results for one action. 3) @Result annotation is used to display single result.
Which tag is used to define interceptor interceptor in Struts2 XML configuration file?
xml file. To define the interceptor, we need to declare an interceptor first. The interceptors element of package is used to specify interceptors. The interceptor element of interceptors is used to define the custom interceptor.
How do you write an interceptor?
To work with interceptor, you need to create @Component class that supports it and it should implement the HandlerInterceptor interface. preHandle() method − This is used to perform operations before sending the request to the controller. This method should return true to return the response to the client.
What is model in Struts 2 framework?
Model contains the data and the business logic. In Struts 2 the model is implemented by the Action component. View is the presentation component of the MVC Pattern. In Struts 2 the view is commonly implemented using JSP, Velocity Template, Freemaker or some other presentation-layer technology.
What is struts2 convention plugin?
The Convention Plugin is bundled with Struts since 2.1 and replaces the Codebehind Plugin and Zero Config plugins. It provides the following features: Action location by package naming conventions. Result (JSP, FreeMarker, etc) location by naming conventions. Class name to URL naming convention.
What is interceptor in API?
Interceptor is an API gateway server built for accepting API requests from the client applications and routing them to the appropriate backend services. May it be a single service or multiple services to be called in a single API call, interceptor provides you with the necessary tools to control your API request flow.
How do you write an interceptor in Java?
We can attach Interceptor to our class using @Interceptor annotation. Whenever a method in our class is called, the attached Interceptor will intercept that method invocation and execute its interceptor method. This can be achieved using @AroundInvoke annotation ( see example below ).
How do you create an interceptor in Struts2?
Struts 2 creating own interceptor
- Create a class implements com. opensymphony. xwork2. interceptor. Interceptor.
- Implement the intercept(ActionInvocation invocation) method.
- Configure the interceptor in the struts. xml.
- Link it to action.
What is ActionContext in struts2?
The ActionContext is the context in which an Action is executed. Each context is basically a container of objects an action needs for execution like the session, parameters, locale, etc. The ActionContext is thread local which means that values stored in the ActionContext are unique per thread.
What is OGNL in struts2?
The OGNL. The Object-Graph Navigation Language (OGNL) is a powerful expression language that is used to reference and manipulate data on the ValueStack. OGNL also helps in data transfer and type conversion. The OGNL is very similar to the JSP Expression Language.
What annotations are used to create an interceptor?
The @AroundInvoke annotation is used to designate interceptor methods for managed object methods.
How do you use interceptor?
The first step is to build the interceptor. To do this, create an injectable class that implements HttpInterceptor. Any interceptor we want to create needs to implement the HttpInterceptor interface. This means that our new class should have a method called intercept with parameters HttpRequest and HttpHandler.
What is filter dispatcher in Struts?
FilterDispatcher was the filter that was provided by Struts 2 for handling all request which needs to be controlled by struts framework. After Struts 2.1. 3 use of this filter was deprecated.