Apache OpenJPA - JEST Syntax

JEST URI Syntax¶

JEST defines URI syntax to access persistent resources over HTTP.

As an example, to find a persistent Person instance with primary key 1234 and receive the result in JSON format, an example URI would look like this (non functional URI):

http://www.example.com:8080/jest/find/format=json?type=Person&1234

The formal notation of a JEST URI is

  URI := http://{host}[:port]/{context}/{action}[/qualifier]* [?argument] [&argument]*

The URI syntax rules, in the light of the above example, are as follows:

protocol is always http
host (www.example.com) and optional port number locates the JEST servlet
context (jest) identifies the context path of the JEST servlet. The context path is the servlet name as specified in the web deployment descriptor for JEST servlet
action (find) is the first segment of the servlet path. Allowed actions are find, query, domain, properties etc.
zero or more qualifier may constitute the servlet path. Each qualifier is separated by / character.
A qualifier must have a key and an optional value.
The qualifier key and value, if present, are separated by = sign.
A qualifier key is a valid Java identifier. The exact key is conditional on the action. For example, find action accepts format qualifier, query action accepts single, named, maxResult, firstResult, format as qualifiers. In the example above, format=json qualifies that the response of find action be formatted as JSON.
A qualifier may or may not have a value. For example, maxResult qualifier for query action must have an integer value while single qualifier does not.
zero or more argument may follow after the path by ? character.
each argument is separated by & character
An argument has an optional key and must have a value.
The argument key, if present, and value are separated by = sign.
some actions may enforce mandatory argument(s). For example, a find action must have type argument and at least one more argument for the primary key. A query action must have q argument etc.

List of supported actions, qualifiers and arguments¶

The following sections tabulates the currently supported actions and corresponding qualifiers and arguments. A bold font denotes qualifier or argument as mandatory.

Action: find¶

Returns the result of a find() operation.

qualifier-key	qualifier-value	Comment
format	`xml` or `json`	default is `xml`
plan		name of one or more fetch plan(s). Each name separated by comma character.
		e.g. `find/plan=onlyBasicFields?type=Person&1234`
		where `onlyBasicFields` is name of a pre-defined Fetch Group

argument-key	argument-value	Comment
`type`	entity name	Fully-qualified Java class name or alias of the entity
	primary key value	can be used for simple identity without the id property name
		e.g. `/find?type=Person&1234`
id property	primary key value	Used for compound primary keys
		e.g. `/find?type=Person&firstName=John&lastName=Doe`

Action : query¶

Returns the result of a Query.getResultList() or Query.getSingleResult() operation.

qualifier-key	qualifier-value	Comment
format	`xml` or `json`	default is `xml`
plan		name of one or more fetch plan(s). Each name separated by comma character.
single		enforces single instance as query result
		e.g. {{/query/single?q=select p from Person p where p.name=:x&x=John}}
named		interprets the q argument value as a named query
		e.g. `/query/named?q=PersonByName&x=John`
		where `PersonByName` is named query with `x` its named parameter

argument-key	argument-value	Comment
`q`	JPQL or Named Query	e.g. `/query/named?q=AllPerson`
		or {{/query?q=select p from Person p}}
		e.g. {{/query?q=select p from Person p where p.firstName=:x&x=John}}
bind parameter	parameter value	the values are converted to match the target type
		e.g. {{/query?q=select p from Person p where p.gender=:g&g=MALE}}

Action : domain¶

Returns the domain model in XML format.

Accepts no qualifier. Accepts no argument.

Action : properties¶

Returns the configuration properties in HTML format.

Accepts no qualifier. Accepts no argument.

Formal syntax:¶

URI := http://{host}[:port]/{context}/{action}[/qualifier]* [?argument][&argument]*

context         := JEST servlet context root
action          := find|query|domain|properties
qualifier       := qualifier-key[=qualifier-value]
argument        := [argument-key=] argument-value
qualifier-key   := any valid Java identifier 
qualifier-value := string
argument-key    := string 
argument-value  := string