@PutMapping and @DeleteMapping in Spring Boot - Step-by-Step Execution

Concept Flow - @PutMapping and @DeleteMapping

Client sends HTTP PUT request

↓

@PutMapping method matches URL

↓

Method updates resource

↓

Return updated resource or status

↓

Client sends HTTP DELETE request

↓

@DeleteMapping method matches URL

↓

Method deletes resource

↓

Return deletion confirmation or status

The flow shows how HTTP PUT and DELETE requests are handled by Spring Boot methods annotated with @PutMapping and @DeleteMapping to update or delete resources.

Execution Sample

Spring Boot

@PutMapping("/items/{id}")
public Item updateItem(@PathVariable int id, @RequestBody Item newItem) {
    // update logic
    return updatedItem;
}

@DeleteMapping("/items/{id}")
public void deleteItem(@PathVariable int id) {
    // delete logic
}

This code updates an item with PUT and deletes an item with DELETE based on the item id.

Execution Table

Step	Request Type	URL	Method Matched	Action Taken	Response
1	PUT	/items/5	@PutMapping("/items/{id}")	Update item with id=5	Return updated item
2	DELETE	/items/3	@DeleteMapping("/items/{id}")	Delete item with id=3	Return deletion confirmation
3	PUT	/items/10	@PutMapping("/items/{id}")	Update item with id=10	Return updated item
4	DELETE	/items/99	@DeleteMapping("/items/{id}")	Delete item with id=99	Return deletion confirmation
5	GET	/items/5	No match	No action	404 Not Found

💡 Execution stops when no matching mapping is found or after response is sent.

Variable Tracker

Variable	Start	After Step 1	After Step 2	After Step 3	After Step 4	Final
id	N/A	5	3	10	99	N/A
newItem	N/A	Provided in PUT body	N/A	Provided in PUT body	N/A	N/A
itemsCollection	Initial items	Item 5 updated	Item 3 deleted	Item 10 updated	Item 99 deleted	Final state

Key Moments - 3 Insights

Why does a GET request to /items/5 not match @PutMapping or @DeleteMapping?

Because @PutMapping and @DeleteMapping only handle PUT and DELETE HTTP methods respectively, not GET. See execution_table row 5 where GET has no match.

What happens if the item id does not exist when updating or deleting?

The method can return a 404 Not Found or handle the error internally. This is not shown in the table but is common practice.

How does Spring know which method to call for a request?

Spring matches the HTTP method (PUT or DELETE) and the URL pattern to the annotated method, as shown in execution_table steps 1-4.

Visual Quiz - 3 Questions

Look at the execution_table, what is the response when a DELETE request is sent to /items/3?

A Return updated item

B Return deletion confirmation

C 404 Not Found

D No action

💡 Hint

Check execution_table row 2 under Response column.

At which step does the PUT request update the item with id=10?

A Step 1

B Step 2

C Step 3

D Step 4

💡 Hint

Look at execution_table row 3 for PUT requests and id values.

If a GET request is sent to /items/5, what will happen according to the execution_table?

A No match, 404 Not Found

B Delete item with id=5

C Update item with id=5

D Return deletion confirmation

💡 Hint

See execution_table row 5 for GET request handling.

Concept Snapshot

@PutMapping and @DeleteMapping handle HTTP PUT and DELETE requests.
Use @PutMapping("/path/{id}") to update a resource by id.
Use @DeleteMapping("/path/{id}") to delete a resource by id.
Spring matches request method and URL to call the correct handler.
Return updated resource or confirmation status after action.

Full Transcript

This visual execution shows how Spring Boot handles HTTP PUT and DELETE requests using @PutMapping and @DeleteMapping annotations. When a client sends a PUT request to a URL like /items/5, Spring calls the method annotated with @PutMapping matching that URL pattern. The method updates the item with id 5 and returns the updated item. Similarly, a DELETE request to /items/3 calls the @DeleteMapping method to delete the item with id 3 and returns a confirmation. If a request uses a different HTTP method like GET, no matching method is found, resulting in a 404 Not Found. Variables like the item id and the collection of items change as updates and deletions happen. This step-by-step trace helps beginners see how Spring routes requests and changes state.