repo.save not storing data in H2 - spring

Question

`I have created simple spring project where I am using requestmapping to store data in my H2 database. I am getting parameters in URL but data is getting saved.
I am new in spring boot and facing this issue. Please help me with this. Thanks
//Controller Class
#Controller
public class TrialTwoController {
#Autowired
Repository repos;
#RequestMapping("/")
public String home() {
return "home.jsp";
}
#RequestMapping(path="/addUser")
public TrailTwo post(#RequestBody TrailTwo trail) {
repos.save(trail);
return trail;
}
}
//Model class
#Entity
public class TrailTwo {
#Id
private int id;
private String name;
public int getId() {
return id;
}
public void setId(int id) {
this.id = id;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
}
Repository Interface
public interface Repository extends JpaRepository<TrailTwo, Integer> {
}
application properties
spring.h2.console.enabled=true
spring.datasource.platform=h2
spring.datasource.url=jdbc:h2:mem:anshul
`

Answer 1

Inside your controller, you want to return TrailTwo entity. However, because you use #Controller and not #RestController, Spring won't be able to return the entity and will try to render the view instead which will result in the exception.
In order to fix this problem, you need to add #ResponseBody for in your method.
#RequestMapping(path="/addUser")
public #ResponseBody TrailTwo post(#RequestBody TrailTwo trail) {
repos.save(trail);
return trail;
}
You can also separate the concerns and have UserController which will be annotated with #RestController and ViewController which will be annotated with #Controller. This way, you won't have to add #ResponseBody annotation inside #RestController.
On another note, make sure to use POST http method for adding new entities. Instead of using #RequestMapping, you can use #PostMapping which will limit the supported http methods to POST. For POST, parameters need to be passed as a part of request body.
Make sure you understand http methods and how to use them to build robust REST apis. It will make your life easier. You can read about different http methods and how to use them here https://restfulapi.net/http-methods/
For the full working example, you can take a look here: https://github.com/CaptainAye/repository-h2-sample