Spring Boot is an excellent tool for quickly developing RESTful web services. In this article, we’ll walk through creating a REST API step by step using Spring Boot.
Spring Boot is an excellent tool for quickly developing RESTful web services. In this article, we’ll walk through creating a REST API step by step using Spring Boot.
REST (Representational State Transfer) is an architectural style for designing web services. It uses standard HTTP methods for communication between clients and servers.
In this subsection, we frame HTTP Methods with concise context so the next example is easier to follow.
| Method | Description | Example Endpoint |
|---|---|---|
| GET | Retrieves a resource. | /api/todos |
| POST | Creates a new resource. | /api/todos |
| PUT | Updates or creates a resource. | /api/todos/1 |
| DELETE | Deletes a resource. | /api/todos/1 |
Before you start, make sure the following are ready:
You can create a Spring Boot project using Spring Initializr. Select the following settings:
Download the project, open it in your IDE, and get ready to run it.
Create a model class for a Todo object:
Add a TodoController class to define CRUD operations as REST endpoints:
Test your API using curl commands:
curl -X GET http://localhost:8080/api/todos
curl -X POST http://localhost:8080/api/todos -H "Content-Type: application/json" -d '{"title": "New Todo", "completed": false}'
curl -X PUT http://localhost:8080/api/todos/1 -H "Content-Type: application/json" -d '{"title": "Updated Todo", "completed": true}'
curl -X DELETE http://localhost:8080/api/todos/1
You now have a practical Building a REST API with Spring Boot implementation with a clear, production-friendly Spring Boot structure. As a next step, adapt configuration and tests to your own domain, then validate behavior under realistic traffic and failure scenarios.
package com.example.demo.model; import lombok.Data; @Data public class Todo { private Long id; private String title; private boolean completed; }
package com.example.demo.model data class Todo( var id: Long, var title: String, var completed: Boolean )
package com.example.demo.controller; import com.example.demo.model.Todo; import org.springframework.web.bind.annotation.*; import java.util.ArrayList; import java.util.List; @RestController @RequestMapping("/api/todos") public class TodoController { private List<Todo> todos = new ArrayList<>(); @GetMapping public List<Todo> getAllTodos() { return todos; } @PostMapping public Todo createTodo(@RequestBody Todo todo) { todo.setId((long) (todos.size() + 1)); todos.add(todo); return todo; } @PutMapping("/{id}") public Todo updateTodo(@PathVariable Long id, @RequestBody Todo updatedTodo) { Todo todo = todos.stream().filter(t -> t.getId().equals(id)).findFirst().orElse(null); if (todo != null) { todo.setTitle(updatedTodo.getTitle()); todo.setCompleted(updatedTodo.isCompleted()); } return todo; } @DeleteMapping("/{id}") public void deleteTodo(@PathVariable Long id) { todos.removeIf(todo -> todo.getId().equals(id)); } }
package com.example.demo.controller import com.example.demo.model.Todo import org.springframework.web.bind.annotation.* @RestController @RequestMapping("/api/todos") class TodoController { private val todos = mutableListOf<Todo>() @GetMapping fun getAllTodos(): List<Todo> = todos @PostMapping fun createTodo(@RequestBody todo: Todo): Todo { todo.id = (todos.size + 1).toLong() todos.add(todo) return todo } @PutMapping("/{id}") fun updateTodo(@PathVariable id: Long, @RequestBody updatedTodo: Todo): Todo? { val todo = todos.find { it.id == id } todo?.apply { title = updatedTodo.title completed = updatedTodo.completed } return todo } @DeleteMapping("/{id}") fun deleteTodo(@PathVariable id: Long) { todos.removeIf { it.id == id } } }
