PUT, PATCH , DELETE

PUT #

• Replaces a resource
  • If the resource exists, it replaces it.
  • If the resource does not exist, it creates it.
  • Simply put, it overwrites it.
• Important! The client identifies the resource.
  • The client knows the resource's location and specifies the URI.
  • Difference from POST

PUT /members/100 HTTP/1.1
Content-Type: application/json

{
	"username": "hello",
	"age": 20
}

Case 1: Resource exists

PUT /members/100 HTTP/1.1
Content-Type: application/json

{
	"username": "old",
	"age": 50
}

->
/members/100

{
	"username": "hello",
	"age": 20
}

=

{
	"username": "old",
	"age": 50
}

Case 2: Resource does not exist

PUT /members/100 HTTP/1.1
Content-Type: application/json

{
	"username": "old",
	"age": 50
}

->
/members/100
No such resource

=

{
	"username": "old",
	"age": 50
}

Caution - Completely replaces the resource

PUT /members/100 HTTP/1.1
Content-Type: application/json

{
    "age": 50
}

->
/members/100

{
	"username": "hello",
    "age": 20
}

=

{
    "age": 50
}

The existing resource is deleted and replaced, so the username field is removed.

PATCH #

• Partially modifies a resource

PATCH /members/100 HTTP/1.1
Content-Type: application/json

{
    "age": 50
}

->
/members/100

{
	"username": "young",
	"age": 20
}

=

{
	"username": "young",
	"age": 50
}

Only age is changed to 50.

DELETE #

• Removes a resource

DELETE /members/100 HTTP/1.1
Host: localhost:8080