Learn all about the second version of the Java Portlet Specification (JSR ). In Version , the specification and the APIs more than doubled. The Java Portlet Specification addresses the requirements of aggregation, was approved by the Java Community Process in March as JSR This tutorial on JSR development provides an introduction to portlet programming as the reader is taken through the creation of a simple HelloWorld portlet.
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For those who want to adopt portals certainly need many and variety of portlets to deploy and run. The Java Portlet Specification V1. The QName and alias names are used to connect public render parameters of different portlets. If you want to provide the portlet with additional capabilities, set an object providing access to these capabilities as a request attribute.
Let’s start by looking into the details of the new resource URL. As mentioned before, the model is a loosely coupled model where the portal application acts as broker between the different portlets and distributes the events. Why do we need this additional Epecification serialization? The important feature in JSR is Inter portlet communication.
Extending GenericPortlet has the additional advantage of being able to use annotations for denoting special methods for handling events, processing actions, and rendering a specific portlet mode.
Specifying the shared property enables the portal to use only one version of such jwr resources per page. Subscribe me to comment notifications.
Validation-based caching is useful for situations in which you do not want to recompute the markup of a portlet often because it is an expensive operation. The ordinary parameter access methods return the merged set of these three parameter maps. The portal should provide UI controls that allow the portlet to switch to this mode.
A portlet can also set the cache scope programmatically using a specufication property or the new CacheControl interface. This page was last edited on 21 Novemberat This setting means that the porrlet can generate a URL that does not contain any interaction state of the page and the portlets on the page. The specification and the APIs more than doubled compared to version 1. Parameters that have the same key first get the resource parameter values merged and then either the private or public render parameter values, depending on whether the parameter key was declared as a public render parameter in portlet.
What’s new in the Java Portlet Specification V2.0 (JSR 286)?
The portlet can declare such a mode in the portlet deployment descriptor with the code shown in listing 6. First, you provide the general event definition, and then you reference this definition in the portlet section with tags that specify that the portlet can either receive or send this event.
Portlets 2 and 3 define that they are able to receive event A in their portlet. A Portlets Catalog is a set of portlets that are ready-to-use components for enterprise portals.
The second version tackles these issues and provides solutions so that specufication portlet programming model has nearly the same capabilities as the servlet one, plus the portlet specific extensions. Use these options with care if you want to develop a portlet that can run on many different portlet container implementations.
This servlet, however, was then addressed directly and not through the portal framework, so it did not have the portlet state provided, nor was it under the security protection of the portal, as you can see in figure 4. Portlet standards platform independent application programming interfaces that are intended to enable software developers to create portlets that can be plugged into any portal supporting the standards. Now, in JSRyou can tell the portlet container that the cache jst can be shared using the cache-scope element in the deployment descriptor.
The define objects tag is now enhanced and gives you the following additional variables beyond the request, response, portletConfig from the V1. Here Portlets catalog are of use. The new Portlet Specifications will add functionality that was not addressed in the first version specification, other JSRs were not final at the time JSR went to public review e.
Thus, you can dramatically reduce the memory footprint for these portlets, as the code in listing 9 shows. This call now allows you to use this ID as key for data that you want to create namespace per portlet window; for example, the portlet specificatioj to cache data that it received from a back-end system per portlet window.
The Java Community Process(SM) Program – JSRs: Java Specification Requests – detail JSR#
The first approach allows more control and flexibility, while the second is easier to use. In some use cases, the portlet wants to offer portlet-specific functionality with the same user look-and-feel as portlet modes supported by the portal for example, with context menus on the portlet window. The first version of the Java Portlet Specification restricted the portlet programming model in some areas compared specifiication the servlet programming model.
The RI will be implemented inside the open source project Pluto at Specifictaion. Articles needing additional references from January All articles needing additional references. This addition means that you can now dispatch to action or event logic written in a servlet, or you can do forwards when serving resources try to forward to the resource ID that you have set on a ResourceURL. Retrieved from ” https: This specification means that you must set at least an expiration time using response.
You can also set an additional resource ID on the resource URL that clearly identifies your resource.
Java Portlet Specification – Wikipedia
What’s new in the Java Portlet Specification V2. From Wikipedia, the free encyclopedia. Portlet Filter and Listeners.
A portlet responds to requests from a web client with and generates dynamic content. This implementation means that changing a render parameter, for example, requires an update of all the URLs on the page, which the portal cannot perform, as the processing of the response data on the client is done entirely by the portlet.
To support these use cases, JSR introduces the portlet-managed modes that are not known to the portal, but are managed by the portlet itself.
For example, the portlet can set a HTTP status code. This is one of the good features.