Quick Answer
PUT and PATCH Mapping in Spring Boot are HTTP methods used to update resources in Spring Boot REST APIs. PUT is designed for full updates, where the entire resource is replaced with new data, while PATCH is used for partial updates, where only selected fields are modified. Choosing the correct method helps avoid data loss and improves REST API design.
Introduction
Updating existing data is one of the most common operations in REST APIs. In Spring Boot applications, developers often confuse PUT and PATCH mapping and use them interchangeably.
In this blog, we will clearly understand PUT vs PATCH mapping in Spring Boot, how each method behaves internally, and when to use which method in real-world backend projects.
What Is PUT Mapping in Spring Boot?
PUT is an HTTP method used to perform a complete update of a resource.When a client sends a PUT request, the server assumes that the request body contains the entire new representation of the resource.
How Does PUT Mapping Work ?
When a PUT request is received:
The entire resource is sent by the client
The existing resource is completely replaced
Even unchanged fields must be sent again
If any field is missing in the request body, it may be stored as null or a default value.
What Is PATCH Mapping in Spring Boot ?
PATCH is an HTTP method used to perform a partial update of a resource.Instead of replacing the entire object, PATCH modifies only the fields provided by the client.
How Does PATCH Mapping Work ?
When a PATCH request is received:
Only the required fields are sent
The existing resource is not fully replaced
Only specified properties are updated
This makes PATCH safer for small updates.
PUT vs PATCH – Key Differences
PUT Mapping
Full resource update
Replaces the existing resource completely
Requires sending all fields
Suitable for large updates
PATCH Mapping
Partial resource update
Updates only selected fields
Requires sending only changed data
Suitable for small updates
PUT and PATCH URL Structure in Spring Boot
Both PUT and PATCH typically use the same URL structure:
/user/{userId}
Example:
/user/1001
The difference between PUT and PATCH lies in the request body, not in the URL.
Request Body Difference Between PUT and PATCH
PUT Request Body
Client sends the complete resource
Existing resource is replaced entirely
PATCH Request Body
Client sends only required properties
Commonly sent as key–value pairs
How PUT and PATCH Are Implemented in Spring Boot ?
Controller Layer
@PutMapping("/user/{userId}")
@PatchMapping("/user/{userId}")Both mappings:
Accept
userIdas a path variableCall their respective service-layer methods
Service Layer Logic (High-Level)
Common First Step
Fetch the resource using
findById(userId)If the resource is not found, throw an exception
PUT Mapping Logic
Fetch existing resource
Replace values using DTO
Save updated resource
Entire resource is overwritten
PATCH Mapping Logic
Fetch existing resource
Update only fields sent by the client
Existing values remain unchanged
Save updated resource
When Should You Use PUT vs PATCH?
Use PUT When:
You are updating many fields
You want to replace the entire resource
The client can safely send the full object
Use PATCH When:
You are updating one or two fields
You want to avoid unnecessary data transfer
A partial update is sufficient
FAQs
What is the difference between PUT and PATCH in REST API ?
PUT replaces the entire resource, while PATCH updates only selected fields.
Can PUT and PATCH use the same URL ?
Yes. Both usually use the same endpoint, such as /user/{id}.
Is PUT idempotent ?
Yes. Repeated PUT requests with the same data produce the same result.
Is PATCH supported in Spring Boot ?
Yes. Spring Boot provides the @PatchMapping annotation for partial updates.
Which method is better: PUT or PATCH ?
Neither is universally better. PUT is suitable for full updates, while PATCH is better for partial updates.
Final Thoughts
PUT and PATCH are not interchangeable methods. Understanding how each one behaves internally helps in designing clean, efficient, and maintainable REST APIs.
Choosing the correct update method improves backend stability and prevents accidental data loss in Spring Boot applications.