I am working on migrating ear application to liberty.
As part of this all jndi lookups to beans are converted to java namespace.
However we have jndi lookups for jms or services provided by server etc.
Do we have to convert this to any other format for it to work on liberty.?
Are there any known limitations related to jms on liberty?
The IBM Websphere Liberty Application Server follows the latest JMS 2.0 specifications, so there are no limitations from that perspective - beside if you used any vendor specific functionality of course. That is something for you to verify.
For example JMS Exception handling, which makes room for vendor implementations. See my answer here.
Regarding JNDI - cant see any problem, did you got any errors? It should work fine, I ve not seen any problem from what I ve been involved in. See the examples about JMS in Liberty at IBM knowledge center
Related
can any one explain java callout a little help will do.Actually i am having several doubts regarding where to add the expressions and message flow jar and where to add my custom jar.
Can i access the resources/java folder directly and can i use it to store my data?
First, check the docs on apigee at
Customize an API using Java
http://apigee.com/docs/api-services/content/customize-api-using-java
Keep in mind Java Callouts are only supported in the paid, Apigee Edge product, not the free Developer platform.
As you decide how to use Java, you should consider this basic hierarchy of policy management:
Policy Configuration First: Apigee policy configurations are in broad use and therefore tested daily by clients and most performant.
Javascript Callout: For stuff you can't do in a standard policy there is Javascript -- keep in mind this is "Compiled Javascript" which means at the time you deploy your project the JS gets interpreted by the Java Rhino engine and then runs like native code. Very fast, very scalable, and very easy to manage as your code is all in plain text files.
Java: You have to have a pretty compelling reason to use Java. Most common cases are where you have some complex connection that needs to be negotiated with custom encryption schemas or manipulating binary content. While perfomant, it's the most difficult code to manage (you upload compiled jars, so if someone takes over your work, the source code is in a separate place than your deployment bundle), and it's the most difficult to debug in the event of a failure.
To your specific question: All Apigee variables are available in Java and Java gives you pretty much god-like powers on the local server where the code is executed. Keep in mind, Apigee's physical architecture is distributed -- your jar may run on different servers for different API calls, so any persistent data (that you might want to store locally) should really be put into Key Value Map and read as needed. Keep your API development as stateless as possible.
Hope that helps.
At work, me and my colleagues, uses geterogenous SOA. We do not use WS, prefering REST and some binary and JSON-based protocols. Due to it, we do not have WSDL-scheme of our service interfaces.
We faced problem providing information about services to our developers, cause they code in different languages, and not always posess information about all services.
The question is - how to solve this problem?
Organize wiki-system, describing each service separately? Store wsdl-like definitions in service registry? What is the best approach?
You may try "Swagger" a framework implementation for describing RESTful web services licensed under the Apache License, Version 2.0 https://developers.helloreverb.com/swagger/
I'm selecting a framework for restful service. Restlet looks promising. However, I'd like to pick something that's mainstream enough that it won't go out of support/development too soon. I know restlet has been around for quite some years. However, I'd like to know if it's popular enough. My questions are,
Any big name companies using it?
Is the default http server good enough for production?
thanks
The Restlet Framework has been available since 2005 when it was the first RESTful web framework for Java. It has support for the JAX-RS API, but its own Restlet API is both client and server-side since day one, much more comprehensive and extensible. We are free to innovate based on our community feed-back, without having to go through lengthy JCP standardization processes.
Also, we just published the 'Restlet in Action' book last September along with its version 2.1. Our internal connector is fully asynchronous and based on NIO and we are constantly stabilizing it even though it isn't ready for heavy productions yet (use the Jetty connector or a Java EE container with no change to your Restlet application).
Its consistent support for Java SE/EE, OSGi, Android, GAE and GWT with dedicated editions is unique. A port to JS (Node.js + AJAX) is also under way. We have also started work on version 2.2 with the first milestone being released (with full Java 6 support, OAuth 2.0 extension based on the final spec, etc.).
In term of references, we have many large companies using it including LinkedIn (see their GLU open source project), IBM, NVidia, ForgeRock, NASA, Sonatype, Apache Camel, Mule ESB, etc. Google has been using it internally as well. See some quotes here:
http://restlet.com/discover/quotes
In January, we'll launch a new community web site as well as APISpark, an all-in-one platform to create, host, manage and use web APIs, directly based on Restlet Framework (PaaS), so the project is active and has an exciting future!
Best regards,
Jerome Louvel
PS: I'm the Restlet Framework creator and lead developer.
The most mainstream you can get is Jersey. It is the official implementation of rest in java. Restlet came out before Jersey. But then Jersey surpassed them (in my humble opinion). I have used both Jersey and Restlet on serious projects. They are both good. However, you will find more support, more books, and more examples on Jersey.
Is this about Java? In that case, JAX-RS is the awesome new API for doing this. The best book for this is Restful Java with JAX-RS. My favorite implementation of it is Jersey, but there are others with their own unique features. All JAX-RS implementations are compatible if you don't use their distinctive features (which are minor anyway). The book explains the core API, the REST philosophy, and also some of the features unique to the different implementations. It is an excellent book. I love the introduction, where the author relates how he was used to traditional remote procedure call (like SOAP, WCF, and ordinary OO semantics) but then saw the light of the REST principles as being simpler and more elegant.
I use Tomcat as the HTTP server (servlet container). It is lightweight and is what Amazon Beanstalk uses (you can just upload your application, the WAR file, to it and it just works). You can also use GlassFish which supports many more JavaEE features, or use Apache for static pages and other things, and forward the REST requests to Tomcat/GlassFish.
The annoying thing about JAX-RS is that it's so powerful and easy that you're tempted to write ideologically-sound REST services. Unfortunately, javascript can't use many of the REST features (setting Accept header, calling anything but GET/POST, etc.) But it's not a big deal.
Jersey also has a fantastic client-side Java API that mirrors JAX-RS and reuses the same annotated classes, if your clients will be Java.
From the article
The Servlet API was released in 1998 and its core design hasn't
significantly changed since that time. It is one of the most
successful Java EE APIs, but it suffers from several design flaws and
limitations. For example, the mapping between the URI patterns and the
handlers is limited and centralized in one configuration file. Also,
it gives control of the socket streams directly to the application
developer, preventing some IO optimizations by the Servlet containers
like the full usage of NIO features. Finally it does not support HTTP
features like caching, content negotiation and content compression
very well, causing too much pain to developers and preventing them to
focus on their application specific code.
Another major concern was the lack of a modern HTTP client API in the
Java EE stack. The JDK's HttpURLConnection class is hard to use and
leaves too much HTTP features unsupported like expressing client
preferences for content negotiation.
Frequently, people were relying on third-party HTTP client APIs to
workaround those limitations. Again, NIO can't be supported with
HttpURLConnection.
In 2005, I saw an opportunity to go beyond all those limitations, and
to design a fresh API in the light of the REST principles. For the
first time, we have an API that unifies client-side and server-side
Web applications, an API that fully supports NIO and an API that lets
the developer programmatically control its container, connectors and
deployed applications without having to constantly rely on XML
descriptors.
How do I browse a jackrabbit repository using a spring-mvc webapp?
How do I map incoming URL requests in the spring web controllers to nodes in the repository? I'd like the users to be able to open a word document in OpenOffice or Word by opening a URL like the following and save back to it via webdav.
http://localhost:8080/my-app/my-doc.doc
Thanks in advance for any ideas.
Éamonn
the Jackrabbit Repository and the associated JSR standard for Java Content Repositories alone provides a fairly low level persistency API, which you could probably use to build Repositories for Domain objects, mapping the data to repository structures such as JCR nodes/properties. You will use the JCR API located at the javax.jcr.* package to manipulate the repository (and for maximum portability). In a sentence, you can use Jackrabbit to replace your database.
A quick google search showed that there are indeed projects that aim to provide similar convenience wrappers to the ones you probably know and love for JDBC and Hibernate, only for JCRs. I found for example the Spring Modules project: http://java.net/projects/springmodules/ which was unfortunately last updated about two years ago, so it is still on JCR 1.0. For sample usage take a look at http://java.net/projects/springmodules/sources/svn/content/trunk/samples/jcr/src/org/springmodules/examples/jcr/JcrService.java?rev=2110
Still, you could probably write your own JCR2Template without a lot of effort, and encapsulate the repetitive tasks such as connection and exception handing by using the Template Method pattern.
So as for the request mapping, you can run the JCR on a separate server, just like you would with a relational database, and connect to it via RMI. Here's an example: http://dev.day.com/content/docs/en/crx/current/developing/accessing_jcr_connectors.html
I would consider this the "clean" way to use a JCR in Spring MVC applications.
As for the WebDAV saving part... I know Jackrabbit does indeed support the mounting of Repositories as WebDAV drives, but I don't really have any experience with it and I honestly can't imagine a way to tell Word to upload a file upon edit somewhere... But I am not a Word expert at all, sorry....
Now ... the Apache Sling Framework on the other hand provides an interesting approach to build RESTful applications, that integrate well with the repository model and some higher level abstractions of the Repository structure. The way Servlets are resolved in Sling, however is completely different from plain Spring MVC (see http://dev.day.com/content/ddc/blog/2008/07/cheatsheet/_jcr_content/par/download/file), so it would a bit of work to reconcile both approaches.
Hope there's some info in there you can use.
Cheers,
Johannes
Right now a lot of my applications use GWT-RPC for retrieving POJO's from a GWT RemoteService which in turn calls a Web Service (SOAP) to get the data. I am evaluating Flex and didn't really see anything truly analogous to this simple architecture. Anything I may have missed?
AMF is Adobe's compact binary message format for use in Flash / Flex applications. BlazeDS is the open source reference implementation for Java, using essentially nothing more than a simple "message broker" servlet to handle requests. This is similar to how services are exposed in GWT, although Blaze uses a single servlet, not multiple as in GWT.
http://opensource.adobe.com/wiki/display/blazeds/BlazeDS/
http://download.macromedia.com/pub/labs/amf/amf3_spec_121207.pdf
BlazeDS, particularly with Spring Integration.
Does this help you? I'm not too familiar with GWT-RPC, but is the AMF protocol what you're looking for?
As others have mentioned, the main choice here is BlazeDS, which is Adobe's open-sores server product for exposing flex-native server RPC and messaging. BlazeDS on its own is a bit clunky, and if you use Spring on the server, there is a slick integration available between Spring and Blaze.
Another, 3rd-party alternative is GraniteDS, which does much the same thing as Blaze, but is Spring-friendly out of the box, and does quite a lot more than Blaze (e.g. runtime compilation and generation of SWF files from the webapp). I haven't tried Granite, but it looks pretty good.