I've got a Spring Boot application packaged as an Uber JAR. One of the wrapped JARs has logic within it to utilize a Java FileSystem for walking a resource tree that is embedded in that particular JAR file.
Unfortunately, this statement appears to be true:
Now opening jar files isn't a big deal. Esp with the introduction of the JarFileSystem. However Spring Boot includes jar files inside their jars. There is currently no support for that. You can't create a JarFileSystem inside a JarFileSystem.
With that being said, Spring Boot has a fair amount of handling surrounding it's wrapped JARs:
JarURLConnection
Everything else under org/springframework/boot/loader/jar
However, there doesn't appear to be any mechanism for registering Spring Boot's approach as a FileSystemProvider...
org.springframework.boot.loader.LaunchedURLClassLoader unable to load 3rd party FileSystemProvider implementation from spring boot executable JAR seemed like a similar problem, but didn't appear to be directly related.
Has anyone had any luck creating a FileSystem for one of Spring Boot's wrapped JARs?
Related
I have a Spring Boot+React application that is packaged as a bundled WAR.
This works well for most cases, but we need to be able to drop-in functionality in some cases that is not part of the bundle (such as via a JAR).
I knew OSGI exists for this case, but not sure of any usage with Spring Boot. Is there another way to do this as well?
If your use case is a kind of small plugin functionality for your spring boot app then you could start an OSGi framework inside spring boot and load bundles from a separate directory. You plugins could then offer their service via an interface that is provided by the spring boot app and an OSGi service with that interface.
You need some good OSGi knowledge for this to work.
I've seen Spring Boot Rest project that generates WAR then deployed in a tomcat container. I wonder if this is best practice because I've also read that in Spring Boot, the new final executable JAR file contains embedded server solution like Tomcat too?
Now i've seen a related post that talks about Spring Boot supports both ways but none talked about the pros and cons of each.
Can someone point out the best practice for deploying a spring boot rest project?
I'm thinking of dockerizing the JAR containing embedded server but i'm wondering if there's any drawbacks vs deploying WAR to Tomcat?
A general best practice ( from 12 Factor App ) regarding the application environment and dependencies is "Explicitly declare and isolate dependencies".
A twelve-factor app never relies on implicit existence of system-wide
packages
With that in mind one should gravitate more towards using embedded container as part of explicit dependency instead of a requirement that needs to be fulfilled separately.There are multiple choices for embedded container in the jar artifact (like tomcat, jetty, undertow, netty) and their respective configuration is also extensive, so using these in production environment is recommended ( I have used them a lot). However there might be certain times when you would want to create a war instead, for e.g., a war file will be deployable in any full-fledged EE Application server ( Weblogic, Wildfly etc) which might be mandated by your environment. With a war, your number of options in terms of app server increases. Personally for me, spring boot jar with embedded tomcat has been quite effective. With embedded container option what you need is a virtual machine with OS and Java installed and you are good to go.
However there is a special limitation related to JSP as mentioned here in Spring Boot documentaion which explain a good reason why you might need to package as a war but still run as jar.
I currently have a project running on JRuby which is packaged in a WAR and deployed on TC Server / tomcat.
I was looking into spring boot and I am wondering if someone can explain how easy / hard it would be to convert that application to run on Spring Boot on JRuby.
.war is packed up as "standard" JavaEE project (see the generated web.xml) - nothing fancy really.
that means that you could add whatever libraries and additional files as you want as long as you understand the JRuby-Rack bootup process. your question is kind of vague as of how Spring should interact with JRuby or if it won't need to interact at all. if not simply add another context listener to boot spring, include the spring .jar files and map the URL handling accordingly.
Pardon if this feels a bit of "necroposting". I looked and found only one similar question with no answers here (Spring-Boot Embedded Wars).
I have a service packaged into a spring boot (1.0) container. This service uses activiti (www.activiti.org) to manage some buisiness processes. I am trying to deploy inside the same spring boot container, the war for activiti-explorer. This war has its own web.inf, spring config, et cetera, so it may conflict with the existing spring config, but nonetheless, I'd like to try to deploy that war as it is.
I haven't found any way to do that, and suspect that spring boot doesn't support the deployment of pre-package wars into the embedded container, isn't it?
Just as a warning, I think I can't put the extracted war into the spring-boot jar as I feel it needs a fully functional web container. If spring-boot doesn't offer this functionality, no big deal, we're going to deploy that war on its own tomcat, but it would be handy if it could be.
Thanks
Update
Just to clear better, I have an already running Spring Application standalone server, with its own embedded Tomcat.
Inside the embedded Tomcat I plugged some #Controllers I developed.
Then I was also able to map a third-party servlet using a ServletRegistrationBean (mapped to /servlet-path).
Now I'd like to do something similar with another war that contains a full fledged web application (it's a vaadin/spring 3.2 application with its own libraries, jsps, static resources ...) and would like to map it to (say) /war-path.
I would like to drop the war in a well known location and deploy it into tomcar with a (say) WarRegistrationBean that would let Tomcat handle all the classloading hurdles (as I mentioned, the war is using spring 3.2 while I'm using 4.0 with spring boot, ...).
I suspect that this last feature is not supported by spring-boot or - possibly - even out of scope for the project itself.
You can manually enhance a war archive by adding the stuff that the boot plugin does (classes from the loader and some META-INF information). Easiest would be to simply enhance an "empty" war, and then merge it with the target one (by exploding them both and re-jarring). The only thing you'd need to add might be a main class.
It's still a gap in the Boot tooling. If you think it needs filling please raise an issue and/or send some code.
I am trying to use to versions of spring in the same application: the first one is a webapp with spring 2.6 and the second it a jar client, with spring 4.0.2. The client communicates with another application and will be a dependency for the webapp. The problem is that the classloader will just load one time the common classes from spring and it will certainly fail.
I tried to use ElasticSearch aproach of using shaded dependencies(maven shade plugin) and relocate spring from the client to a different package (from org.springframework to my.springframework) and the uber jar seems to be constructed fine.
The issue is that Spring is based on spring.schemas and spring.handlers for validating xml config files and loads this files from classpath (META-INF folder and this paths are hardcoded in Spring code - e.q. PluggableSchemaResolver). I modified this files to point from org.srpingframework to my.springframework.
At runtime it seems that the classloader reads these files from the webapp, which has this files but with the real spring path and the exception is something like
org.realsearch.springframework.beans.FatalBeanException: Class [org.springframework.context.config.ContextNamespaceHandler] for namespace [http://www.springframework.org/schema/context] does not implement the [my.springframework.beans.factory.xml.NamespaceHandler] interface.
To me it seems that is impossible to achieve what I am trying (use tho spring versions in the same application with one of them relocated). Any ideas here? Am I wright?:d