I have just built a RESTful web service with Spring Boot.
I now want to utilise the RESTful web service and start making calls to it by building a java console application (eventually adding GUI and security).
I was wondering if I can use any of the Spring functionality outside of the Spring (Boot) environment and use it in my java console application? For example, can I use Spring's RestTemplate in my non-Spring java application to make the REST api calls? I am new to Spring and I want to stick as close to Spring as possible. I think you can't, but I just want to make sure.
If not possible, I know you can create non-web application with Spring. Is it possible to integrate a GUI? Might not be best practice, just exploring what is possible and conventional.
Spring Boot is not coupled, in any way, to an application type. You can run command-line only apps, batch apps, web apps or any other kind of apps with it. You can even benefit from Spring Boot's auto-configuration.
In the case of the RestTemplate you may want to import spring-web directly rather than spring-boot-starter-web. Or you could add the starter and exclude the embedded container (spring-boot-starter-tomcat). Spring Boot will auto-adapt and not start an embedded web server in that case.
Related
and if not what are more things that we can do with spring boot?
i know that we can build a whole web app(frontend and backend) in one spring boot application in the folder resource/template and resource/static but in the real world does somebody uses this method to create web application with the resource/template and resource/static?
and one more question what is used in the real world hibernate(with the SessionFactory or EntityManager) or JpaRepository in the spring data jpa?
No Spring Boot isn't just for REST APIs.
Spring Boot is "just" a mechanism for autoconfiguring a Spring Framework based application.
Therefore you can use and it does get used for all kinds of stuff.
REST APIs for webservices
Full web application using Spring MVC
SOAP services (or are they called SOAP dispensers?)
Reactive web applications
Command line tools
Batch jobs
Swing / JavaFX applications
...
Of course there are many more people writing web applications than Swing applications with or without Spring.
The kind of web application you describe and which I put under "Full web application using Spring MVC" is a very well established model and when done right way better aligned with the principles of REST than the average so called REST service. My very personal guess is: They will still be around when nobody remembers what Angular is.
For your additional question:
Your question sounds a little like the relation between JPA and Spring Data JPA might not be completely clear.
(see Spring Data JDBC / Spring Data JPA vs Hibernate)
Both are certainly used in real world projects. By definition more projects use JPA than Spring Data JPA since the first is a superset of the later.
This involves complete Spring history,
Actual motive of Spring was to enable loose coupling , so that unit tests can be easily performed . Spring MVC was for developing web applications with Model View Controller having their proper boundaries.
Then Spring Boot which enabled developer to focus on business logic then configurations. That's why spring boot is a good choice for microservices.
For JPA or hibernate query , many people prefer using JPARepositoy as again you just have to define entity for the repository and Spring boot automatically provides you queries like findById and so on.
In short Spring boot have made it really easy to run the applications with different configurations and environment smoothly.
Is Spring Boot just for Microservices or can I use Spring Boot for Monolithic architecture?
Spring Boot in itself has nothing to do with microservices. It's a Spring module which simply makes the configuration of your app easier. As such, it absolutely can be used in a monolithic app.
From the official docs:
Spring Boot makes it easy to create stand-alone, production-grade Spring based Applications that you can "just run".
We take an opinionated view of the Spring platform and third-party libraries so you can get started with minimum fuss. Most Spring Boot applications need very little Spring configuration.
Features
Create stand-alone Spring applications
Embed Tomcat, Jetty or Undertow directly (no need to deploy WAR files)
Provide opinionated 'starter' dependencies to simplify your build configuration
Automatically configure Spring and 3rd party libraries whenever possible
Provide production-ready features such as metrics, health checks and externalized configuration
Absolutely no code generation and no requirement for XML configuration
I know that Spring Boot, in contrast to Spring Framework, does not support WAR deployment for Spring WebFlux applications. My question is simple: will it ever in the future?
My use case is this: we have a lot of customers that still live in the traditional "we deploy everything on application server X" world. So although we would like to push standalone JARs, they are not ready (yet). We heavily use Spring Boot, and would really like to continue to do so, so abandoning that is not an option.
We are building reactive applications and would like to use Spring WebFlux for that, but we still need to deploy to application servers, so that is not an option. In the meantime we avoid Spring WebFlux and simply use Controllers, which works, but is not as elegant. Hence my question.
There are no plans to support Spring WebFlux with war deployments. However, you can use reactive return types, Reactor's Mono and Flux and those from RxJava, with Spring MVC packaged and deployed as war. That will allow you to build an entire reactive pipeline as you would with WebFlux, but deployed to an application server. It doesn't give you all of the benefits of full-blown reactive (no event loop-based concurrency, for example), but it can be a good middle ground for those in your situation.
Everything I found on the internet about Spring Cloud Netflix is about running microservices from Boot applications using #EnableEurekaClients and so on.
Now I'm trying to connect my logging microservice within a traditional war application (springmvc, jaxws etc) - piece of legacy which can not be converted to Boot or modified in any way (by technical task).
I've created a new maven module "log-server-client" that knows nothing about upper web layer and intended to be used as a simple dependency in any maven project.
How should I configure access to Spring Cloud Netflix for this simple dependency? At least, how to configure Eureka and Ribbon?
I just extracted some lines of code from RestTemplate and created my custom JmsTemplate (microservice works with jms remoting with apache camel and activemq), exactly how it is done in RestTemplate, but this code stil lacks connection to infrastructure
afaik, we can create a global singleton bean, run a separate thread from this bean, and run Boot app from this thread, but don't you think that it is very ugly and can lead to problems? How it really should be used?
Great question!
One approach is to use a "sidecar". This seems to be a companion Spring Boot application that registers with the Eureka Server on behalf of your traditional web app.
See e.g.:
http://www.java-allandsundry.com/2015/09/spring-cloud-sidecar.html
http://cloud.spring.io/spring-cloud-netflix/spring-cloud-netflix.html#_polyglot_support_with_sidecar
Another approach is to use the following library:
"A small lib to allow registration of legacy applications in Eureka service discovery."
https://github.com/sawano/eureka-legacy-registrar
This library can be used outside of Spring Boot.
What are the advantages of using Spring Rest Web Services over Core Servlet ?
As we know Spring Rest Web Services also use Servlet internally.
REST is a special kind of web service. Whether this is the right thing for your application varies. If it is you should use a framework/library that is designed for REST to make coding simpler. You might also want to have a look at JAX-RS.
If you need a non-REST web service Servlet may be an option, but there are other options, too.
REST is not a type of Web Service - it is an Architecture and specification - JAX-RS. Spring has its own REST implementation libraries primarily based on its MVC controller. I would recommend you not to go for Spring Rest Web Services until you have any Spring specific requirement (Though I cant think of any such requirement which cant be solved by other light wait JAX-RS implementations). Jersey is the most light weight JAX-RS reference implementation by Sun/Oracle which, has support for Spring as well which, can be plugged in on requirement basis.