I have encountered a task where we had to create a website client to send data to our web-service to enable bulk data import for testing purposes. In this article I will show you how you can create your own client with Spring — without any Spring Boot requirements.
As mentioned in the article series of the Variations project I’ll use Spring as the core business logic framework. For the persistence Layer I’ll introduce now Hibernate.
Hibernate provides a mapping between Java objects and relational database tables and vice versa. Let’s look how to do it.
First of all: more delay in the posts because I’ve changed my job this week so I do not have as much time to write as I prefer.
And now about this article: the Initializr project of Spring is something you can start along with. I’ve found it as I went through the Spring Boot project for some fun.
As mentioned in the previous article I’m going to write some words about dependency injection — with Spring. As stated before there exist a lot of good books and articles about DI and I will only tell my opinion of the usage of DI. And I’ll focus on DI with Spring. Eventually I’ll take a look at JSR-330.
As a little milestone in the “Variations” project I’ll introduce Spring as a configuration and dependency injection framework, inversion of control container and so on — after the big part Liquibase.
I will not give a full stack introduction to Spring. I suggest you to read a book in this topic, there are many good introductory and pro books about Spring on the market. If you want to have an application quickly up and running search between the guides on Spring (take a closer look at Spring Boot).
The integration with Spring is not a big thing. You only have to configure your data source, the Liquibase bean and that’s it. OK, this sounds simple but there are really some pitfalls if you’ve never done this.
OK, imagine you work on a software which has a lot of modules, you have a database in the background and you use it. You create, read, update and delete data, the reading queries contain sometimes an IN clause where you enter some values. Beside this
you are damned you are forced you have to use Oracle as DBMS.
One day you get a bug report from your QA that something does not work what worked in the last… months. You look up the StackTrace (it’s good if you have one) and see following error message:
|ORA-01795:||maximum number of expressions in a list is 1000|