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Implementing long polling server using Dropwizard 0.7.0
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Closed 8 years ago.
I have a requirement to implement websocket with a dropwizard project. However i am unable to find any document related to it. Can any one point out resources for the same.
I've been dealing with the same problem, and thought I would like to share my solution:
http://cvwjensen.wordpress.com/2014/08/02/websockets-in-dropwizard/
I use the Atmosphere framework and the solution defaults to using websockets, but can downgrade to long-polling if required.
That should be enough to get you started...
I'm looking to do this too. This is the best information I've found so far:
Supposedly one of the most popular websocket frameworks out there works well with Jersey (Jersey is bundled with Dropwizard). You can find more about it here: https://github.com/Atmosphere/atmosphere
Also, someone has published a repository integrating the two of them together: https://github.com/mgutz/dropwizard-atmosphere/
I implemented websockets into a Dropwizard project by including CometD.
CometD includes a servlet for dealing with WS requests, and Dropwizard exposes the environment to let you register arbitrary servlets.
A small excerpt from my application (Groovy):
environment.addServlet(new Initializer(httpClient, amqpConsumer), "/_initializer")
.setInitOrder(2)
environment.addServlet(AnnotationCometdServlet, "/cometd/*")
.addInitParams([
transports: 'org.cometd.websocket.server.WebSocketTransport',
services: EventService.getCanonicalName(),
jsonContext: 'org.cometd.server.JacksonJSONContextServer',
maxSessionsPerBrowser: serviceConfiguration.maxBrowserSessions.toString(),
maxInterval: '7200',
logLevel: "2"
]).setInitOrder(1)
An initializer servlet makes things easy, as shown in the CometD tutorials.
Related
I am going to teach myself some Java EE and making a simple web portal where people can generate their own invoices(pdf lib is needed). Not asking about any code but can you give advice (examples) which technologies I can make use of through the process? I have decided to use "Spring MVC" as the framework + java/Kotlin as a compiler. Some database + server + email+ some micro services?, are needed but which can it be? Thank you!
If you are trying to implement microservices, i prefer spring boot which has embedded tomcat with additional services, and for database you can use open source mysql
if you are also planning for UI stuff and new to it prefer basic Html,css and Bootstrap
If I am there here are my choices. All these choices are based on my past 4 complete end to end web application project experience.
Spring Boot
Using spring boot create micro services. As it has in built tomcat it will be easy to deploy any environment, either local laptop or on premise server or cloud server.
JPA with Hibernate
If you are looking for free you can choose MYSQL. As it has strong community support
almost all the issues you are going to face would have been asked and answered already under stack overflow or somewhere else in the internet. Another think is as you chose JPA you can switch to any database easily.
React
As of now the simplest and one of the fastest ui framework. Also it has strong user support. You can find answer to almost all questions you will have on internet.
Apart from all, you can extend any of these technologies. Happy Coding!!!
You may want to consider using Jaspersoft for generating your pdf files:
https://www.jaspersoft.com/reporting-software
https://community.jaspersoft.com/wiki/introduction-jaspersoft-studio
There may undoubtedly be other solutions out there, but this is the one I'm most used to.
Lagom by default uses Google Guice as implementation od DI pattern.
I would like to use Spring Framework instead.
Is it possible? IF so, how should it be done?
I have successfully integrated Akka with Spring (using hints from documentation and Internet), however I cannot find anything in documentation about integrating with Spring.
Possible? Yes. Will you be constantly swimming upstream, with reach upgrade break in new and unexpected ways requiring you to debug undocumented internal APIs? Most probably.
Lagom is built on Play, Play's DI support is ostensibly pluggable, when I wrote it I hacked together a proof of concept to ensure that Spring could be plugged into it. But it was only ever a proof of concept, neither I or the Play team ever had any desire or intention of maintaining it, so I published my work to GitHub:
https://github.com/jroper/play-spring
So that anyone for whom Spring support was important could continue where I left off. That was 3 years ago. In spite of a community of over a hundred thousand developers, no one ever took the work up. There's not a lot of work to do on the module itself, where most of the work would be is in Play and Lagom to fix areas where they have grown incompatible with Spring.
But really, why do you want to use Spring? The whole Lagom and Play ecosystems are built on Guice, saying you want to use Spring with Lagom is like saying you want to use a narrow gauge train in a country that only has standard guage rails, you're going to have to build yourself an entire new rail system to do so. What do you hope to achieve?
I was thrown into a CXF-based project in which the basic HowTo tutorials are easy to follow and implement but the moment there is a problem or a bug in the system, all kinds of exceptions are thrown without me understanding any of the relationship between the various components.
I know that CXF builds on top of Spring.
But I have no experience with Spring and I don't know how it works.
I have also seen references to JAXWS in the cxf.xml but I don't know how it is related to either Spring or CXF.
I can build a perfectly working (simple) CXF-based web service. Contract first, using wsdl2java in a pom.xml (copycatting a sample).
But the moment I face a problem, I am stumped, relying on some tips and clues gleaned from the web.
Ideally, I would like to have a tutorial that walks me through the history of how web services evolved from Java only, to J2EE, to JAXWS, to Spring, to CXF.
But I couldn't find any.
I did find the official Apache CXF documentation but it assumes a lot of prior knowledge that is more than just knowing the Java language.
Any recommendations on how to get to a point of truly understanding what I am doing when I build a web service?
A recommended book? Online tutorial?
Thanks.
Yip it is a bit of a learning curve but well worth it. As far as books are concerned you can try the following.
Apache CXF Web Service Development
Spring In Action
Please be aware that J2EE and Spring are not evolutionary linked to each other Spring was more a reaction to the heavy weight J2EE specification of old. CXF is a web services toolkit/API that can be used outside of J2EE as well.
I would suggest you also join the user lists of the CXF projects and ask questions there. Also why not post some of the code causing exceptions here so we can help you with more detail?
Has anyone integrated Spring Dynamic Modules (or Eclipse Gemini Blueprint) with Netbeans Platform? I cannot find any information on this.
I was thinking about potential use of Spring Services within the Netbeans Platform Application. Is this reasonable?
Thanks!
I don't know anything about Spring Dynamic Modules, but as long as it produces regular Spring services and DAOs, it's totally do-able. I outlined the process in this post. I am now also considering writing up a blog post complete with code examples on this topic since this seems to be a common issue. I'll update this answer with a link as soon as I'm done.
Does anybody has an experience with Spring Integration project as embedded ESB?
I'm highly interesting in such use cases as:
Reading files from directory on schedule basis
Getting data from JDBC data source
Modularity and possibility to start/stop/redeploy module on the fly (e.g. one module can scan directory on schedule basis, another call query from jdbc data source etc.)
repeat/retry policy
UPDATE:
I found answers on all my questions except "Getting data from JDBC data source". Is it technically possible?
Remember, "ESB" is just a marketing term designed to sell more expensive software, it's not a magic bullet. You need to consider the specific jobs you need your software to do, and pick accordingly. If Spring Integration seems to fit the bill, I wouldn't be too concerned if it doesn't look much like an uber-expensive server installation.
The Spring Integration JDBC adapters are available in 2.0, and we just released GA last week. Here's the relevant section from the reference manual: http://static.springsource.org/spring-integration/docs/latest-ga/reference/htmlsingle/#jdbc
This link describes the FileSucker with Spring Integration. Read up on your Enterprise Integration patterns for more info I think.
I kinda think you need to do a bit more investigation your self, or do a couple of tries on some of your usecases. Then we can discuss whats good and bad
JDBC Adapters appear to be a work in progress.
Even if there is no specific adapter available, remember that Spring Integration is a thin wrapper around POJOs. You'll be able to access JDBC in any component e.g. your service activators.
See here for a solution based on a polling inbound channel adapter too.