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.
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In My Application, Using the below technologies
Spring boot 2.7.x
Cassandra
spring batch 5. x
java 11
As part of this, I need to extract data from the Cassandra database and need to write out the file
so here I need to use queries to fetch data so
just want to know what is the best way to maintain all queries at one place so any query changes come in the future, I shouldn't build the app rather just need to modify the query.
Using a repository class is necessary. If you are using JPA i recommend using a repository for each Entity class. With JDBC it is possible to create a single repository which contains all the queries. To access the query methodes i would use a service class. In this way your code is structured well and maintainable for future changes.
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.
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
Searched over the net but unable to find the satisfying approach.
I am new to spring boot and aware of starter dependancies,
I want to develop a springboot app using elastic search as a storage system.
Wherever i searched i found that somewhere my service class will have to implement some interface from springframework for ES crud operations.
Is there any other way without implementing or extending the components.
I myself want to create transport client and want to query ES by my code or methods not by overidden ones.
Please if you ahve ever seen any projects you can redirect me to that link .
Thanks.
Assuming I understand you correctly, you can use the Elasticsearch REST client: https://www.elastic.co/guide/en/elasticsearch/client/java-rest/current/java-rest-low.html
You supply the JSON entities for the queries and parse the responses yourself. Its pretty basic in what it does, so you're not dependent on a lot of third party stuff to perform operations.
I recently worked on a project which uses Spring Data REST with Spring Boot. While it is GREAT to harness the power of Spring Data REST and build a powerful web service in no time, I have come to regret one thing: how tightly coupled the "presentation" layer (JSON returns) is to the underlying data structure.
Sure, I have used Projections and ResourceProcessors to manipulate the JSON, but that still does not completely sever ties with the database structure.
I want to introduce Controllers to the project, to integrate some of the "old" ways of building a web service in Spring. But how should I draw the line? I don't want to eradicate Spring Data REST from my project.
I am sure many of you have faced similar decisions, so any advice would be most appreciated!