Is it possible to:
Create a jar which has AOP annotation(custom) for intercepting rabbitmq listener to write the message to DB.
Pass this jar around as dependency to other spring based applications to get their messages in the DB.
Need clarifications:
1. How do we read the method argument, message here?
2. Can pointcut be read from properties so that any application using it provides its own pointcut by adding a property in like application.properties
3. Is there any special consideration about when the jar will be loaded so that the functionality is available as soon as the application starts?
Related
I have a spring boot based spring application that is deployed into an external tomcat instance.
The application creates few datasources. These datasources are added to entitymanager and transaction manager is setup accordingly.
However, recently we have integrated programmatically an ETL tool that works with JNDI datasources. The ask here is to bind the current spring datasources into the JNDI tree at startup.
I have tried to create an initial context post datasource bean creation and bind the datasources there, however, i do see a NoInitialContext exception being thrown.
How can i bind these spring datasources into the JNDI tree of the external tomcat? Appreciate the help!
Note: I cannot/am not allowed to edit the tomcat configuration as it is initialized from a PaaS template. So need to work on the approach of being able to bind to the JNDI tree from within the application.
AFAIK this is not possible. Take a look at the JEE spec:
The container must ensure that the application component instances have only read access to their naming context. The container must throw the javax.naming.OperationNotSupportedException from all the methods of the javax.naming.Context interface that modify the environment naming context and its subcontexts.
Jakarta EE Spec - Resources, Naming, and Injection
See this SO post has some interesting code examples if you want to play around.
IMHO you can achieve what you want by creating JNDI resources and passing these to the EntityManger/Spring. But that means that the configuration would exist outside of Spring completely. So this may not do what you want to do.
I'm new to spring integration. I need to fetch some file via sftp and immediately start some processing on the content of that file. There is SFTP Inbound Channel Adapter that partially satisfy me. But it saves(as documentation says) fetched file in local directory. I have no possibility to save it on local machine, but just want to start processing the content of that file, so it will be good for me to retrieve remote file as byte array or as InputStream. How can I achieve this with spring integration?
Also I want to configure my system to periodically fetch that file. I know that I can configure spring bean with #Scheduled annotation on some method and start processing from that method. But, maybe, spring integration has more elegant solution for such case?
Spring Integration 3.0.1 has a new RemoteFileTemplate that you can use to programmatically receive a file as a stream. See the Javadocs.
I am new to Spring Integration and I am considering using it in order to poll a directory for new files in order to process those files.
My question is: is Spring Integration some sort of daemon one can launch and that one can use in order to poll a directory?
Is this is possible can someone please direct me to relevant section of the official documentation on how to launch Spring Integration?
All you need is to have a main method (or a WAR file if you want to deploy to Tomcat or another servlet container) that creates a Spring ApplicationContext (e.g. new ClassPathXmlApplicationContext("file-poller.xml"))
It can run with a cron trigger, fixed-rate or fixed-delay trigger.
JMX operations can be exposed on Spring Integration's File adapter (or any adapter) by simply adding a single config element (e.g. <mbean-export>).
Bottom line: you REALLY do not need an ESB if you simply want a File poller to run continuously. You can have a single small config file and one line of code in a main method.
Visit the samples for more info: https://github.com/springsource/spring-integration-samples (look under basic/file specifically)
Hope that helps,
Mark
Spring Integration is a part of framework, its not a programm or daemon.
What you cant do — is to configure Spring Integration to poll a directory, lunch JVM with Spring onboard and poller will do what you want.
You can start with this blog post.
More samples
Relevant section of documentation
I'm currently developing a small EJB 3 application for WebSphere AS 7 with WebSphere-MQSeries. It's a very simple app that mainly consists of one MDB listening on a queue, convert the incoming messages and write the extracted data into a db. I've finally got up it and running, but I'm a bit confused regarding ActivationConfig annotations in the code, the ibm-ejb-jar-bnd.xml and the activation spec in WAS itself. My main question is, why do I need ALL of them? Why should/could I specify things like the queue name or destinaton type via annotation (#ActivationConfigProperty) when I still need a activation spec in WAS where I also specify the destination e.g. Queue-Name? I addition I also need a binding via an xml file? Is that right? Is it also possible to specify the activationspec-name via annotation and thus get rid of the xml binding file? Can I avoid creating the activation spec in WAS?
Hope someone can clarify things, thanks.
You cannot avoid the Activation Spec entity because it is responsible to open connection to your JMS provider, query messages according to various options like the message selector filter.
According to WebSphere 7 InfoCenter EJB-3 annotations can replace activation specification properties from binding file but the properties required by WebSphere are not standard.
So as far as I know, you have to provide:
either the binding file, written manually or edited with the deployer tool
either at deployment setting properties in the administrative console or in automated jython/wsadmin script
Be aware that the Activation Spec is a runtime component that can be stopped, typically after some rollbacks on messages. In that case, it no longer consumes message and your MDB has nothing to process until you re-activate it from the WebSphere console.
I'm using Spring 2.5.6. I have a bean whose properties are being assign from a property file via a PropertyPlaceholderConfigurer. I'm wondering whether its possible to have the property of the bean updated when the property file is modified. There would be for example some periodic process which checks the last modified date of the property file, and if it has changed, reload the bean.
I'm wondering if there is already something that satisfies my requirements. If not, what would be the best approach to solving this problem?
Thanks for your help.
Might also look into useing Spring's PropertyOverrideConfigurer. Could re-read the properties and re-apply it in some polling/schedular bean.
It does depend on how the actual configured beans use these properties. They might, for example, indirectly cache them somewhere themself.
If you want dynamic properties at runtime, perhaps another way to do it is JMX.
One way to do this is to embed a groovy console in your application. Here's some instructions. They were very simple to do, btw - took me very little time even though I'm not that familiar with groovy.
Once you do that you can simply go into the console and change values inside the live application on the fly.
You might try to use a custom scope for the bean that recreates beans on changes of the properties file. See my more extensive answer here.
Spring Cloud Config has facilities to change configuration properties at runtime via the Spring Cloud Bus and using a Cloud Config Server. The configuration or .properties or .yml files are "externalized" from the Spring app and instead retrieved from a Spring Cloud Config Server that the app connects to on startup. That Cloud Config Server retrieves the appropriate configuration .properties or .yml files from a GIT repo (there are other storage solutions, but GIT is the most common). You can then change configuration at runtime by changing the contents of the GIT repo's configuration files--The Cloud Config Server broadcasts the changes to any Client Spring applications via the Spring Cloud Bus, and those applications' configuration is updated without needing a restart of the app. You can find a working simple example here: https://github.com/ldojo/spring-cloud-config-examples