Using @PathVariable in Spring Boot Retrieve Data from Dynamic URLs

When developing REST APIs, it’s common to retrieve dynamic data directly from the URL. Spring Boot offers the @PathVariable annotation to make this process straightforward and efficient.

In this blog post, I’ll walk you through how to use @PathVariable by building a real example: retrieving an employee by ID.

Use Case: Get Employee by ID

Let’s say er already have a list of employees. Now we want to build an endpoint that returns a specific employee by their ID.

Here is the controller method we’ll use:

@GetMapping(path = "/employee-list/{id}")
public Employee getEmployeeById(@PathVariable(name = "id", required = true) String id) {
    return employeeService.getEmployeeById(id);
}

Explanation

• /employee-list/{id} : This endpoint accepts a dynamic id value in the URL.
• @PathVariable( name = “id”, required = true) : This annotation tells Spring to extract id from the URL and pass it into the method.

Service And Repository Layers

In the EmployeeService, we delegate the logic to the repository:

public Employee getEmployeeById(String id) {
    return employeeRepository.getEmployeeById(id);
}

And in the repository, we search the list of employees for a matching ID:

public Employee getEmployeeById( String id ) {
    Employee findEmployee = null;
    for( Employee employee: employeeList) {
        if( id.equels(employee.getId())) {
            return employee;
            break;
        }
    }
    return findEmployee;
}

Testing the API with Postman

You can retrieve the employee with ID 2 by sending this request:

GET http://localhost:8080/rest/api/employee-list/2

Response:

{
    "id": "2",
    "firstName": "Ahmet",
    "lastName": "Alan"
}

✅Why Use @PathVariable?

• Provides clean and RESTful URL structure
• Avoids unnecessary query parameters
• Simplifies endpoint definations

🎯 Conclusion

Using @PathVariable in Spring Boot is one of the easiest and most powerful ways to build flexible REST APIs. With just a few lines of code, you can extract dynamic values from the URL and return personalized results.