To specify the data format that will be returned to the user when they request a URL, in Spring MVC we can use the @RequestMapping annotation with the produces attribute. How is it in detail? Let’s find out in this tutorial! First, I will create… Read More
Suppose, you are working on a project where the database has two tables, such as student and clazz, structured like below:
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CREATE TABLE `clazz` ( `id` int(11) NOT NULL, `name` varchar(255) DEFAULT NULL, PRIMARY KEY (`id`) ) ENGINE=InnoDB DEFAULT CHARSET=utf8; CREATE TABLE `student` ( `id` int(11) NOT NULL, `name` varchar(255) DEFAULT NULL, `clazz_id` int(11) DEFAULT NULL, PRIMARY KEY (`id`), FOREIGN KEY (`clazz_id`) REFERENCES `clazz` (`id`) ) ENGINE=InnoDB DEFAULT CHARSET=utf8; |
As you can see, the clazz table has columns id and name with the primary key id. Student table has columns id, name… Read More
Using the @RequestParam annotation along with the @RequestMapping annotation we can bind the parameter request with the method argument in Spring MVC. How is it in details? We will find out in this tutorial. Assuming now, we need to build a Controller to handle the… Read More
Annotation @ManyToOne in JPA is used to express multiple-to-one relationships between two tables in a database. There are many records in table A related to a record in table B. For example: many different students may have the same class. In this tutorial, we will… Read More
In JPA, to express one relationship to another, for example, a tourist can have a single room in a large hotel, we will use the @OneToOne annotation. How is it in details? In this tutorial, let’s learn about annotation @OneToOne in JPA! First, I will… Read More
In JPA, the EntityManagerFactory object is an entity management object that manages the connection to the database. Using Spring to manage this object will help us a lot in developing Java applications that use JPA. In this tutorial, I will guide you on how to… Read More
In the previous tutorial, I introduced with you all about the Optional object in Java. In this tutorial, let’s find out some ways to initialize your Optional object in Java. OK … First, we can initialize an Optional object with the nulled reference variable. For… Read More
In the previous tutorial, we looked at what Dependency Injection is. So, in this tutorial, we will go into Inversion of Control (IoC), and find out the relationship between these two concepts. As I said, with Dependency Injection, an object does not depend on another… Read More
In this tutorial, I will guide you on how to deploy a Spring Boot application in Docker. The steps, we need to take, are: Create a simple Spring Boot project. Write Dockerfile Deploy the application to the Docker Container. OK, let’s get started. Create a… Read More
Assume, you are installing multiple Java versions in macOS, so how do you change from one version to another? In this tutorial, I will guide you to do this. First, let’s open Terminal and enter the following command to check all the Java versions that… Read More
