I've been working a lot with Symfony recently, and I really like the ability to define routes in a routing.yml file. I was looking into Spring's routing system and I couldn't find any options other than placing routes in annotations on controller methods. Is it possible to accomplish something like this in Spring?
My first thought was creating an abstract controller that grabs the routes from a .yml file, but that seemed a bit hacky.
EDIT:
For some added context, I am looking to build a simple Database API with Spring. After some digging it looks like the routing.yml file is best suited for working with server-rendered pages, which is not what I aim to do with my Spring project.
Symfony and Spring are different framework. You are used to one use and want to use same it in another entirely different system. It will not work. You have to adapt to frameworks.
Spring will scan your project and collect your specific annotation like Controller/Component/Configuration/... and configures itself. Therefore, there is no need predefined project structure, unlike, for example, Laravel. So, you can define this structure if you want. Or every class can be in one package, just not beautiful.
Back to routing. You can configure them by the value of annotations only. This is interpreted at compile time. (Ofc, there are runtime annotations, but I focused parameters of annotation.) So, you can not use configuration from the file because it is already runtime. So, you should use constants or hardcode.
Or, you can use an alternative: Annotate the interfaces, then the controllers will be the implementations.
Alternative #2: If you use Spring with Kotlin, In Kotlin, you can have several classes or interfaces in one file.
Related
I have a spring boot application that reads from an excel document. This is currently being done by a service that my controller uses.
Currently the path of the document is hard coded in the Service class. I would like to know, if this is the best way to do it.
I would also like to know the best practises for unit testing my code. How do I ensure that I have no dependency with the actual file. My helper method is private. I am having troubles mocking it.
Configuration details should be externalized for both convenience (easy deploy, testing) and security (plain text in your code vs environment variables). Here's a good discussion on the subject.
Mocking is the way to unit-test it. You should be more specific on the problems you have with this and IMHO it would be best to ask that in another question.
You can provide the path in your "application.properties" file by any variable name.
For example :
my-file=/home/path/to/file.extension
Then, in your service class, declare a variable like :
#Value("${my-file}")
private String filePath;
Now file will have the value which you provide in the application properties. When your application starts, it will automatically binds the path of your file in your variable. In this way, it is easy for you to modify the path. Spring framework will magically manages it out of the box.
I have a use case where I would like build a common interface or service which can update entities of application. Example case is shown as below:
Now every application has to handle update functionality of entities. Rather than implementing update functionality in n application module. I would like to build a common interface or server in spring boot.
Service will be like below:
My question is how to design service/interface which can used for above scenario. Any api or tool which can help me to achieve this. I dont want to write code for update in every application module.
Thanks in advance.
Last year I was thinking about the similar concept to yours, but in Apache Camel framework context. I haven't got enough time and motivation to do so, but your post encouraged me to give it a try - perhaps mostly because I've found your concept very similar to mine.
This is how I see it:
So basically I considered an environment with application that might uses N modules/plugins that enriches application's features, i.e. processing feature etc. Application uses module/plugin when it is available in the classpath - considering Java background. When the module is not available application works without its functionality like it was never there. Moreover I wanted to implement it purely using framework capabilities - in this case Spring - without ugly hacks/ifs in the source code.
Three solutions come to my mind:
- using request/response interceptors and modifying(#ControllerAdvice)
- using Spring AOP to intercept method invocations in *Service proxy classes
- using Apache Camel framework to create a routes for processing entities
Here's the brief overview of POC that I implemented:
I've chosen Spring AOP because I've never been using it before on my own.
simple EmployeeService that simulates saving employee - EmployeeEntity
3 processors that simulates Processing Modules that could be located outside the application. These three modules change properties of EmployeeEntity in some way.
one Aspect that intercepts "save" method in EmployeeService and handles invocation of available processors
In the next steps I'd like to externalize these Processors so these are some kind of pluggable jar files.
I'm wondering if this is something that you wanted to achieve?
link to Spring AOP introduction here: https://docs.spring.io/spring/docs/5.0.5.RELEASE/spring-framework-reference/core.html#aop
link to repository of mentioned POC: https://github.com/bkpawlowski/spring-aop
Currently we have a number of classes that extend TemplateMethodModelEx which we construct using Spring and then inject into the Freemarker Configuration as shared variables so they are available as functions to all of our templates.
However, it would be nicer to have more fine grained control and make these methods available on demand in individual templates. One can instantiate them using the ?new built in, but internally that uses the general Java reflection mechanism for instantiating the class, and these models need to be constructed via Spring to get their dependencies.
In a perfect world, I'd like to make it so that the ?new built in use Spring to construct the class. It looks like to do that I would need to find a way to overload BeansWrapper.newInstance(Class, List) to use Spring, but I'm unclear on the best way to accomplish that.
Note that we are currently using Freemarker 2.3.23
Grails has amazing validation; is it possible to use it independent of the Grails framework?
We have a Java/Groovy Camel-based web application we can't convert to a Grails application. I'd love to use the Grails-style validation with the declarative constraints but have been unable to successfully configure the application to work with Grails libraries without converting the whole thing.
The validation provided by Grails is just a wrapper around Spring's bean validation framework. Since Grails is open source you can take a look at how it's done and adapt it to your own needs. The best place to start looking is the GrailsDomainClassValidator and DomainClassGrailsPlugin to get an idea of how it's done. Another point of interest would be the #Validateable AST annotation.
As far as I know, and from what I can see in the source, there isn't a stand alone way to do this outside of a Grails project without writing your own adaptation/implementation.
You can use a external validation without problem. It is possible, for example, using a external "jar" (that do a validation) file on the "lib" folder of your Grails project. Through this way, you can use the API of this jar file. It's a simple way that you can use.
I have a mongo repository with connectivity between multiple components. I have a traditional java application which reads the mongo repository and performs the routing, transformation by calling appropriate java classes dynamically. I am planning to move this to spring but do not want to statically declare routes as this is highly inflexible. Is there any possibility to make sure that spring can refer routes and transformations from mongo and performs the routing.
It's not entirely clear what you are looking for but, yes, it's easy to create custom routers, transformers and/or other components.