Understanding PUT vs. PATCH in REST APIs with Spring Boot

Introduction

In RESTful APIs, both PUT and PATCH are used to update resources, but they serve different purposes. Understanding their differences is crucial to implementing efficient and correct API operations.

This article explores PUT vs. PATCH with unique Spring Boot examples to illustrate their impact on resource updates.

1. PUT vs. PATCH: Key Differences

1.1 PUT (Full Update)

Definition: Replaces an entire resource with a new representation. If a field is missing in the request, it will be removed (set to ).

• Use case: When updating a resource entirely.

• Downside: Requires sending all fields, even if only one field changes.

1.2 PATCH (Partial Update)

Definition: Updates only the specified fields without affecting others.

• Use case: When updating a few fields in a resource.

• Benefit: More efficient, as it avoids sending unnecessary data.

2. Example Scenario: Employee Management System

Imagine we manage an Employee Profile System where employees have:

3. Implementing PUT and PATCH in Spring Boot

3.1 Employee Entity

3.2 Employee Repository

3.3 Employee Controller

4. Testing PUT and PATCH Requests

4.1 PUT Example (Full Update)

Request:

Response (After PUT):

Notice: Since we did not send , it was set to .

4.2 PATCH Example (Partial Update)

Request:

Response (After PATCH):

Notice: Only was updated; remained unchanged.

5. Best Practices and Considerations

5.1 When to Use PUT vs. PATCH?

✅ Use PUT when updating the entire resource (e.g., form submission, profile update). ✅ Use PATCH when updating specific fields (e.g., changing only an email or department).

5.2 Avoiding Common Mistakes

❌ PUT request missing fields leads to unintended data loss (e.g., values). Always ensure all necessary fields are present. ❌ PATCH misuse can lead to inconsistencies if validation is not handled properly.

5.3 Enhancing PATCH with JSON Merge Patch

A more advanced way to handle PATCH updates is by using JSON Merge Patch, which allows specifying only modified fields:

6. Conclusion

Understanding the differences between PUT and PATCH ensures we use the right HTTP method for updating resources in RESTful APIs.

• PUT is ideal for full updates, where all fields must be provided.

• PATCH is best suited for partial updates, modifying only specific fields.

By implementing these strategies correctly, we ensure our Spring Boot APIs remain efficient, scalable, and maintainable. 🚀

💡 What do you use more in your projects? PUT or PATCH? Let’s discuss in the comments!

#SpringBoot #Java #RESTAPI #HTTPMethods #BackendDevelopment #Microservices