How should I add Spring task scheduling to a non-Spring war project? Currently, the web project only has a maven dependency to org.mitre.dsmiley.httpproxy:smiley-http-proxy-servlet. It's just a simple proxy servlet now. SpringBoot is probably not a good fit for this problem as I want to keep the war artifact the deployment model. I do not want to run it embedded in a stand-alone container. I'm looking for the least intrusive approach. Any suggestions?
If you are planning to deploy the app to a server that supports Servlet 3.0, then it is actually quite easy to use Spring Boot in a traditional, war deployment model.
What you need to do is:
Extend SpringBootServletInitializer, which in turn implements WebApplicationInitializer and can configure the servlet context.
Specify the war packaging in your pom.xml (which you probably already have)
Set the provided scope for the spring-boot-starter-tomcat dependency, so that an embedded server is not created when your application runs.
See the reference guide for more details.
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 am new to Spring MVC and I have now come accross tutorials that explain how to deploy your web project as a .jar. My IDE is the Spring Tool Suite. I have always used .war + Apache Tomcat.
Can someone elaborate a bit from the practical point of view why to use .jar instead of .war? Any problems to be aware of?
edit: other answers are welcome too
Spring Boot uses fat JAR packaging where is embeds Servlet container with all dependencies into this single JAR.
If you are using Maven, it uses spring-boot-maven-plugin to package the project.
Practical usage of this approach is simple. Ability to easily run Srvlet based Spring application from command line with externalized properties. Such configuration enables powerfully orchestration possibilities which are often used in modern enterprises in so called Microservices or SOA architecture.
There is group of people out there (including myself) which believe that deploying various WAR files of unrelated applications into single Servlet runtime is not very good idea.
So fat JARs are handy for separate Servlet runtime per application deployment.
About having .jar and Tomcat + .war on the same machine, it is possible and I use this. This may be not cool but I had a .war application running in a tomcat server before the rise up of spring boot. Now my new apps are spring boot apps, and we are migrating our architecture to SOA concept, but we can't change the tire with the moving car. The main application, the WAR is running in a tomcat server and the others (.jar) are self contained ( embedded tomcat ), each one running in a different port. It was the most viable solution available for us by the moment.
I am trying to convert my existing multi-module maven Spring project to Spring Boot project. The reason is make it self contain and follow Martain Fowler's microservices concept.
However, the problem I have encounter is when try to clean build, seems the spring boot is trying to find the Main method from every module, which of course will failed.
Is this feature currently supported by Spring Boot 1.1.6.RELEASE or I did something wrong?
Thanks
It sounds like you've added Spring Boot's Maven plugin to every module in your build – it's what's looking for a main method. You should only add the Spring Boot plugin to a module if its a service that you want to run. If the module's just code that's shared between your services, the Spring Boot plugin isn't needed in that module.
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.