In addition, initialization parameters for the servlet are specified by means of the strutsconfig. Struts 2 tutorial 11 login action and best practices part 2. You can download the latest version of sdk from oracles java site. Struts 2 tutorial the actionsupport class duration. It is a convenient class that implements many interfaces such as action, validateable, validationaware, textprovider, localeprovider and serializable. Sep 18, 2003 the struts action invocation framework looks to improve how struts handles actions adding features like action interceptors and inversion of control ioc. What is struts action class in java j2ee how to use java67. Example of struts action that extends actionsupport class. It uses the beans scripting framework to allow scripts to be written in any language bsf supports like perl, python, ruby, javascript, beanshell, and even vbscript. Hi viral you have showed best and easy way of spring struts configuration. The controller actionservlet will select an appropriate action for each request, create an instance if necessary, and call the perform. I am trying to download a file with struts2 but when i click on the hyperlink to download the file.
The hello action defined in the above view file will be mapped to the helloworldaction class and its execute method using struts. It is available in a full distribution, or as separate library, source, example and documentation distributions. Its the developers responsibility to create these classes. Action configuration apache struts apache software. Struts2 supports annotation based configurations which are easy to create and more intuitive.
Action class acts as wrapper around the business logic and provides an inteface to the applications model layer. Understand how to implement file download action class in struts with a sample application. It contains business logic and the way to next action. Create maven web project struts 2 dependencies web. So you need to add this jar file to your project class path. Strutstestcase for junit is an extension of the standard junit testcase class that provides facilities for testing code based on the struts framework. Simple action class any concrete java class can be used as a struts 2 action class but the only requirement is that the class must contain a execute method with the string return type. Apache struts 2 is an elegant, extensible framework for creating. Instead of creating the action by extending simple action class and writing all. This facility provides the power to hide package name in url. In action class, declared an inputstream data type and its getter method. Struts 2 is very flexible in terms of development and configurations and we will see how easy it is to develop a web application using struts 2 framework. It is strongly recommended to perform all the database related stuffs in the action.
Because the action class is integral to the struts framework, netbeans ide provides you with a wizard. An action class handles the client request and prepares the response. Struts 2 is based on opensymphony webwork framework. It also decides where the response should be forwarded. The use dispatchaction we need to extend our action class to org. Strutstestcase provides both a mock object approach and a cactus approach to actually run the struts actionservlet, allowing you to test your struts code with or without a running servlet engine. Class actionsupport provides default implementations for the most common actions e. Using struts tags to build input form and print value in result page. Lets see the example of action class that extends the actionsupport class. Which java class has to respond to the users action request.
The struts 2 framework will create an object of the helloworldaction class and call the execute method. A basic understanding of mvc framework and jsp or servlet is. It is a convenient class and prefered than actioncontext class. Each method of an action class can be fetched by a separate url. If you observe, it has downloaded the maven dependencies and a pom. When a user clicks on the submit button it will cause the struts 2 framework to run the execute method defined in the helloworldaction class and based on the returned value of the method, an appropriate view. The action classes code is not tightly coupled to the struts framework or. In the action class all the databasebusiness processing are done. Also, how to use actioncontext objects and expression language in struts 2 framework. To do this we need to overwrite the execute method. This is the method where we define the behavior of the current action.
The action should receive the request, call business objects and then determine the further step. Thus each request will go through the struts2 framework and it will decide wheather an action is available which can be called or default action should be allowed. Lets look at an example model class, action, server page, and mapping. Most of the s1 framework s implementation references action, meaning that in order to fulfill framework method signatures and return values, you must subclass action.
When a request matches the actions name, the framework uses the mapping to determine how to. This tutorial will introduce you to the basics of writing the controller logic in the action class. Web applications usually involve interaction with database, execution of business logic and rendering the result on the browser. Basically an action class receives data from the presentation layer and forwards the data to the corresponding business layer. The struts action invocation framework looks to improve how struts handles actions adding features like action interceptors and inversion of control ioc. Struts extend the java servlet api and are based on the model view controller or mvc design pattern. You can read more details on how to create maven eclipse web project. Each url is mapped to a specific action, which provides the processing logic which is necessary to service the request from the user. This is done by using an actionmapping class and developers use the. Action class in struts framework is used to define the business logic it handles the client request prepare the response or tell where the response should be forward, basically its receive the data from the view layer and forward that data to specific business layer or process the data and again forward the processed data to view layer.
Actionservlet passes the parameterized class to action form using the execute method. The action mapping above also specified that if the execute method of class helloworldaction returns success then the view helloworld. Download a file as an inputstream through struts 2 framework with. This project allows struts actions to be written in the scripting language of ones choice rather than as java classes. But the action also serves in two other important capacities. Below diagram shows different component of struts 2 in a web application. Essentially, the action maps an identifier to a handler class.
Action class in struts framework defines the business logic. It expects this file to be present in classpath webinfclasses of the application when the source is. A brief of what struts framework is and how it works. If you use older struts version, then download struts library files for the version. In this lesson i will show you how to use struts action class and forward a jsp file through it. This file includes all of the routing and configuration information for the struts application. Actioncontext is a set of objects or we call it as storage of the objects which are related to the current requestresponse of a web application. This jar file is already included in example for this tutorial. In struts and in lots of older software programs were written to implementations, not interfaces. Action,i want to create a domcumentbuilder through a documentbuilderfactory.
Generally, the struts taglib tags are used to help web application developers to. Here is the action class code for the hello world application. When form data is received, it is the execute method of an action object that processes the data and determines which view to forward the processed data to. Explain various action classes used in struts framework mrbool. Explain various action classes used in struts framework. Aug 28, 2012 thus each request will go through the struts2 framework and it will decide wheather an action is available which can be called or default action should be allowed. Creating an action class for java struts web framework. You will notice that in any struts 2 application, there is an action class associated with different type of client action. Struts 2 provide rest plugin to implement rest web service.
Action class can be viewed as a glue between the view and the model layer of mvc architecture. Struts 2 framework example part 3 action actionsupport. Its primary function is the mapping of a request uri to an action class selecting the proper application module. The action class contains the business logic in the application. In this above configuration you also can add the parameter attribute, where you can specify the file full path which has to be downloading. The actionservlet command passes the parameterized class to action form using the execute method. The action class is part of the model and is a wrapper around the business logic. Learning from other web frameworks like webwork 2xwork, saif hopes to be a testbed for the integration of the best features of other web frameworks into struts. Tutorialaction not found action tawheed dec 30 at 1.
Hello world using struts 2 apache struts apache software. Struts 2 hello world annotations example howtodoinjava. Instead of creating the action by extending simple action class and writing all necessary code for. When a users request is received by the controller, controller uses mapping information from this file to select appropriate action class. Above, the struts controller servlet is named action and is defined in the struts library org. In the download example, javadoc comments are included. The action class must implement the execute method which would be invoked by the controller.
Actions are the core of the struts2 framework, as they are for any mvc model view controller framework. Basically an action class receives data from the presentation layer and forwards. When i implement the action class, i encounter a question frustrates me. Class actionsupport provides default implementations. A tutorial on java struts web framework through program. Struts 2 action is at the front of our application that takes care of handling client requests. Struts2 supports annotation based configurations which are easy to create and more. Struts2 action mapping example examples java code geeks 2020. Also struts framework will try to load its configuration from struts. Action class in struts 2 act as the model in the web application. Define core classes of struts framework,action class in. An action class to return an application file instead of the normal html page, and get the superfish.
The business logic is wrapped by the action class and this class provides an interface to the model of the application. Been banging my head for quiet sometime now as i dont seem to understand why struts is unable to find my action class. Actioncontext in struts 2 struts tutorial by wideskills. The return type of the execute method is actionforward which is used by the struts framework to forward the request to the file as per the value of the returned actionforward object. If you observe, it has downloaded the maven dependencies and a. Action classes respond to a user action, execute business logic or call upon other classes to do that, and then return a result that tells struts what view to render. This page will provide the struts 2 and rest web service integration example. An action class in the struts application extends struts org.
How to configure action class and view mapping in struts. Construct input html forms with the struts html tags defined in strutshtml. It is also possible that more than one url pattern can point a single point of execution. Action class in struts framework defines the business. Struts 2 tutorial one stop solution for beginners edureka. Architecture of struts 2 framework features and enhancements in struts 2. Dec 16, 2008 hi viral you have showed best and easy way of spring struts configuration. The commonly used methods provided by servletactioncontext class are as follows.