HTTP Methods

The persistence to the datastore is performed via HTTP methods as following:

Method Operation URL format Return Arguments
POST Insert object /{full-class-name} The JSON Object is returned. The JSON Object is passed in the HTTP Content.
PUT Update object /{full-class-name}/{primary key} The JSON Object is returned. The JSON Object is passed in the HTTP Content. The primary-key is specified in the URL if the PK is application-identity single field or if it is datastore-identity
DELETE Delete object /{full-class-name}/{primary key} The primary key fields are passed in the HTTP Content (JSONObject) if the PK uses multiple PK fields, otherwise in the URL.
DELETE Delete all objects of type /{full-class-name}
GET Fetch all objects of type /{full-class-name} JSON Array of JSON objects
GET Fetch a single object /{full-class-name}/{primary key} A JSON object The primary key fields are passed in the HTTP Content (JSONObject) if the PK uses multiple PK fields, otherwise in the URL
GET Query objects via a filter. Returns a JSON Array of objects /{full-class-name}?{filter} JSON Array of JSON objects Filter component of a JDOQL query
GET Query objects via JDOQL. Returns a JSON Array of objects /jdoql?{JDOQL-single-string-query}

/query?{JDOQL-single-string-query} 		JSON Array of JSON objects JDOQL single string query
GET Query objects via JPQL. Returns a JSON Array of objects /jpql?{JPQL-single-string-query} JSON Array of JSON objects JPQL single string query
HEAD Validates if an object exists /{full-class-name}/{primary key} The primary key fields are passed in the HTTP Content (JSONObject) if the PK uses multiple PK fields, otherwise in the URL


HTTP Method samples
Insert a new object of class using application identity

This inserts a Greeting object. The returned object will have the "id" field set. 

POST http://localhost/dn/mydomain.Greeting
{"author":null,
 "content":"test insert",
 "date":1239213923232}

Response: 

{"author":null,
 "content":"test insert",
 "date":1239213923232,
 "id":1}


Insert a new object of class using datastore identity

This inserts a Person object. The returned object will have the "_id" property set. 

POST http://localhost/dn/mydomain.Person
{"firstName":"Joe",
 "lastName":"User",
 "age":15}

Response: 

{"firstName":"Joe",
 "lastName":"User",
 "age":15,
 "_id":2}


Update an object of class using application identity

This updates a Greeting object with id=1, updating the "content" field only. 

PUT http://localhost/dn/mydomain.Greeting/1
{"content":"test update"}


Update an object using datastore identity

This updates a Person object with identity of 2, updating the "age" field only. 

PUT http://localhost/dn/mydomain.Person/2
{"age":23}


Fetch all objects of class using application identity

This gets the Extent of Greeting objects. 

GET http://localhost/dn/mydomain.Greeting

Response: 

[{"author":null,
  "content":"test",
  "date":1239213624216,
  "id":1},
 {"author":null,
  "content":"test2",
  "date":1239213632286,
  "id":2}]


Fetch object with id 2 using datastore identity
GET http://localhost/dn/mydomain.Person/2

Response: 

{"firstName":"Joe",
 "lastName":"User",
 "age":23,
 "_id":2}

Note that it replies with a JSONObject that has "_id" property representing the datastore id.



Query object of class using application identity

This performs the JDOQL query 

SELECT FROM mydomain.Greeting WHERE content == 'test'

GET http://localhost/dn/mydomain.Greeting?content=='test'

Response: 

[{"author":null,
  "content":"test",
  "date":1239213624216,
  "id":1}]


Fetch object using Application PrimaryKey Class (JSON)
GET http://localhost/dn/google.maps.Markers/{"class":"com.google.appengine.api.datastore.Key","id":1001,"kind":"Markers"}

Response: 

{"class":"google.maps.Markers",
 "key":{"class":"com.google.appengine.api.datastore.Key",
        "id":1001,
        "kind":"Markers"
       },
 "markers":[
            {"class":"google.maps.Marker",
             "html":"Paris",
             "key":{"class":"com.google.appengine.api.datastore.Key",
                    "id":1,
                    "kind":"Marker",
                    "parent":{"class":"com.google.appengine.api.datastore.Key",
                              "id":1001,
                              "kind":"Markers"
                             }
                   },
             "lat":48.862222,
             "lng":2.351111
            }
           ]
}