org.lacibus.storeapi

Class StoreApi

java.lang.Object

org.lacibus.storeapi.StoreApi

All Implemented Interfaces:

java.io.Serializable

public class StoreApi
extends java.lang.Object
implements java.io.Serializable

A Web API to a triple store.

See Also:

Serialized Form

Constructor Summary

Constructors

Constructor and Description
StoreApi(SessionIssuer sessionIssuer) Construct an interface to the triple store that can be invoked using HTTP.

Method Summary

Modifier and Type	Method and Description
void	authorizeAndProcessCommand(java.lang.String command, java.util.Map<java.lang.String,Datum> inputs, javax.servlet.http.HttpServletResponse response, StoreSession storeSession) Process a command, obtaining authorization from inputs, and place the results in an HTTP response
StoreSession	getAuthorizedStoreSession(Datum authDatum, StoreSession requestingSession) Get the authorized store session from an input datum containing authorization in the form of a credential with its correct key.
org.json.simple.JSONArray	getChanges(java.util.Map<java.lang.String,Datum> inputs, StoreSession authorizedSession) Get the changes of an update
static org.json.simple.JSONObject	getJsonFromDatum(Datum datum, java.util.Map<java.lang.String,Datum> binaries) Get a JSON object representing a Datum
void	handleHttpRequest(java.lang.String command, javax.servlet.http.HttpServletRequest request, javax.servlet.http.HttpServletResponse response, StoreSession storeSession) Handle an HTTP request.
org.json.simple.JSONObject	newItemsJo(java.util.Map<java.lang.String,Item> newItemsMap, StoreSession authorizedSession) Get a JSON object representing the new items.
java.util.Map<java.lang.String,Datum>	processCommand(java.lang.String command, java.util.Map<java.lang.String,Datum> inputs, StoreSession authorizedSession) Process a command using an authorized session
org.json.simple.JSONArray	query(JoinConstraint[] constraints, java.util.Map<java.lang.String,Datum> outputBinaries, StoreSession authorizedSession) Handle a query.
java.util.Map<java.lang.String,Item>	update(org.json.simple.JSONArray changes, java.util.Map<java.lang.String,Datum> inputs, StoreSession authorizedSession) Handle an update

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

StoreApi

public StoreApi(SessionIssuer sessionIssuer)

Construct an interface to the triple store that can be invoked using HTTP.

Parameters:

sessionIssuer - the session issuer of a triple store. It includes a reference to the store.

Method Detail

handleHttpRequest

public void handleHttpRequest(java.lang.String command,
                              javax.servlet.http.HttpServletRequest request,
                              javax.servlet.http.HttpServletResponse response,
                              StoreSession storeSession)
                       throws java.io.IOException

Handle an HTTP request. The request must be a POST request.

This method gets the inputs, establishes the authorized store session to process the request, invokes one of the specific request handling methods, and places the result in the response.

Parameters:

command - the command to be processed. If it is null, the command is obtained from the HTTP request. If it is not null, it supersedes the command in the HTTP request.

request - an HTTP POST request conveying a command and its inputs. The command is the value of the request "command" parameter. It can be 'query" or 'update'. The inputs are supplied in the multipart form data content.

response - the response to the request.

storeSession - the requesting store session, or null. If the request includes authorization input then its credential is used to generate the authorized session for processing the command. If the request does not include authorization then the command is processed with an authorized session whose access level is the lowest (public) level.

Throws:

java.io.IOException

java.lang.Exception

authorizeAndProcessCommand

public void authorizeAndProcessCommand(java.lang.String command,
                                       java.util.Map<java.lang.String,Datum> inputs,
                                       javax.servlet.http.HttpServletResponse response,
                                       StoreSession storeSession)
                                throws java.lang.Exception

Process a command, obtaining authorization from inputs, and place the results in an HTTP response

Parameters:

command - the command to be processed

inputs - authorization and command parameters

response - the HTTP response in which the results are to be placed

storeSession - the requesting store session

Throws:

java.lang.Exception

processCommand

public java.util.Map<java.lang.String,Datum> processCommand(java.lang.String command,
                                                            java.util.Map<java.lang.String,Datum> inputs,
                                                            StoreSession authorizedSession)
                                                     throws java.lang.Exception

Process a command using an authorized session

Parameters:

command - the command to be processed

inputs - the command parameters

authorizedSession - the store session to process the command

Returns:

the values resulting from processing the command

Throws:

java.lang.Exception

getAuthorizedStoreSession

public StoreSession getAuthorizedStoreSession(Datum authDatum,
                                              StoreSession requestingSession)

Get the authorized store session from an input datum containing authorization in the form of a credential with its correct key. The authorized store session has the access level authorized by the credential. If the input datum is null then the authorized store session is a session that has the public access level.

Parameters:

authDatum - an input datum containing authorization information.

requestingSession - the requesting store session.

Returns:

the authorized store session, or null if invalid authorization is supplied.

Throws:

java.lang.Exception

query

public org.json.simple.JSONArray query(JoinConstraint[] constraints,
                                       java.util.Map<java.lang.String,Datum> outputBinaries,
                                       StoreSession authorizedSession)
                                throws java.lang.Exception

Handle a query.

Parameters:

constraints - the request constraints.

outputBinaries - a map to which an entry is added for each binary value in the solutions

authorizedSession - the authorized store session

Returns:

the data retrieved.

Throws:

java.lang.Exception

getChanges

public org.json.simple.JSONArray getChanges(java.util.Map<java.lang.String,Datum> inputs,
                                            StoreSession authorizedSession)
                                     throws java.lang.Exception

Get the changes of an update

Parameters:

inputs - a map whose "json" entry is a string representation of a JSON array whose members are JSON objects specifying the changes, and whose other entries include the binary values referenced by these JSON objects.

authorizedSession - the authorized store session

Returns:

a JSONArray specifying the changes.

Throws:

java.lang.Exception

update

public java.util.Map<java.lang.String,Item> update(org.json.simple.JSONArray changes,
                                                   java.util.Map<java.lang.String,Datum> inputs,
                                                   StoreSession authorizedSession)
                                            throws java.lang.Exception

Handle an update

Parameters:

changes - a JSONArray specifying the changes.

inputs - the input parameters of the request. It includes entries giving the binary values of the changes.

authorizedSession - the authorized store session

Returns:

a map of the new items created by the changes, keyed by their handles.

Throws:

java.lang.Exception

newItemsJo

public org.json.simple.JSONObject newItemsJo(java.util.Map<java.lang.String,Item> newItemsMap,
                                             StoreSession authorizedSession)
                                      throws java.lang.Exception

Get a JSON object representing the new items.

Parameters:

newItemsMap - a map with an entry for each new item, whose key is the item's handle, and whose value is the item's identifier.

authorizedSession - the authorized store session

Returns:

a JSON object representing the new items.

Throws:

java.lang.Exception

getJsonFromDatum

public static org.json.simple.JSONObject getJsonFromDatum(Datum datum,
                                                          java.util.Map<java.lang.String,Datum> binaries)
                                                   throws java.lang.Exception

Get a JSON object representing a Datum

Parameters:

datum - a datum.

binaries - a String-Datum map to which an entry will be added if the datum is a Binary datum.

Returns:

a JSON object representing the datum.

Throws:

java.lang.Exception