com.epimorphics.rdfutil

Class SPARQLUpdate

java.lang.Object

com.epimorphics.rdfutil.SPARQLUpdate

public class SPARQLUpdate
extends Object

Low level support for POSTing SPARQL update requests to a server. Supports logging of the entire request to a file and serialization of models. Typical sequence:

   SPARQLUpdate up = new SPARQLUpdate(server);
   up.open();
   up.sendPrefixes(model);
   up.send(command);
   up.send(model, true);
   up.send(command);
   up.close();
   int status = up.getStatus();
   boolean ok = up.wasSuccessful();
 

Version:

$Revision: $

Author:

Dave Reynolds

Field Summary

Fields

Modifier and Type	Field and Description
protected HttpURLConnection	conn
protected BufferedWriter	logFile
protected BufferedWriter	out
protected String	responseBody
protected String	responseMessage
protected boolean	started
protected int	status
protected URL	target

Constructor Summary

Constructors

Constructor and Description
SPARQLUpdate(String server) Constructor.

Method Summary

Modifier and Type	Method and Description
void	close() Finish the update command, capturing the result status and any return message
String	getResponseBody() Get the body of the HTTP response, in the event of an error response the server may return useful human readable information in the body.
String	getResponseMessage() Get the message part of the HTTP response, generally not interesting
int	getStatus() Get the returned status code from the request
boolean	isStarted() Return true if at least one command string has been sent, whether complete or not
void	open() Open the POST channel to the server
void	performUpdate(String preamble, org.apache.jena.rdf.model.Model model, String postamble) Convenience packaging of common pattern of use.
void	send(InputStream in) Write a set of formatted SPARQL Update instructions to the stream
void	send(org.apache.jena.rdf.model.Model model) Write a model as part of the update request, typically the body of and INSERT DATA {} or DELETE DATA {} request but it is up to the caller to send the surrounding command syntax.
void	send(org.apache.jena.rdf.model.Model model, boolean turtle) Write a model as part of the update request, typically the body of and INSERT DATA {} or DELETE DATA {} request but it is up to the caller to send the surrounding command syntax.
void	send(String command) Send a string (hopefully part of a SPARQL update command!) to the server
void	sendPrefixes(org.apache.jena.shared.PrefixMapping pm) Write the prefixes from the given model (or other prefix mapping) in SPARQL update syntax.
void	sendUpdate(String preamble, org.apache.jena.rdf.model.Model model, String postamble) Convenience packaging of common pattern of use.
void	setLogFileBase(String filebase) Request that the entire formatted update request be recorded in a timestamped file with the name "-.log".
boolean	wasSuccessful() Return true if the update succeeded (response code 2xx or 3xx)

Methods inherited from class java.lang.Object

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

Field Detail

logFile

protected BufferedWriter logFile

target

protected URL target

status

protected int status

responseMessage

protected String responseMessage

responseBody

protected String responseBody

conn

protected HttpURLConnection conn

out

protected BufferedWriter out

started

protected boolean started

Constructor Detail

SPARQLUpdate

public SPARQLUpdate(String server)

Constructor. Throws an unchecked exception (EpiException) if the server URL is malformed.

Parameters:

server - URL of the of the server which should be send the request

Method Detail

setLogFileBase

public void setLogFileBase(String filebase)

Request that the entire formatted update request be recorded in a timestamped file with the name "-.log". Throws an unchecked exception (EpiException) if the file can't be created or is not writable

Parameters:

file - name of the file to log to

open

public void open()

Open the POST channel to the server

send

public void send(String command)

Send a string (hopefully part of a SPARQL update command!) to the server

isStarted

public boolean isStarted()

Return true if at least one command string has been sent, whether complete or not

sendPrefixes

public void sendPrefixes(org.apache.jena.shared.PrefixMapping pm)

Write the prefixes from the given model (or other prefix mapping) in SPARQL update syntax. This is separated from send(model) because in SPARQL update the prefix block comes before the command.

send

public void send(org.apache.jena.rdf.model.Model model,
                 boolean turtle)

Write a model as part of the update request, typically the body of and INSERT DATA {} or DELETE DATA {} request but it is up to the caller to send the surrounding command syntax.

Parameters:

model - the model to send

turtle - if true then the model will be send in compact turtle syntax using any prefixes declared in the model (the caller must have issued sendPrefixes at the start of the update for this to be legal), if false then N-Triple syntax will be used which is more verbose but faster to write and does not require prefixes

send

public void send(org.apache.jena.rdf.model.Model model)

Write a model as part of the update request, typically the body of and INSERT DATA {} or DELETE DATA {} request but it is up to the caller to send the surrounding command syntax. Uses N-triple syntax so that the model data is self-contained with no requirement to have declared prefixes.

send

public void send(InputStream in)
          throws IOException

Write a set of formatted SPARQL Update instructions to the stream

Throws:

IOException

performUpdate

public void performUpdate(String preamble,
                          org.apache.jena.rdf.model.Model model,
                          String postamble)

Convenience packaging of common pattern of use. Opens the connection if not already open, sends Model prefixes, then preamble command, then the model (using compact Turtle) then postamble command then closes.

sendUpdate

public void sendUpdate(String preamble,
                       org.apache.jena.rdf.model.Model model,
                       String postamble)

Convenience packaging of common pattern of use. Opens the connection if not already open, sends Model prefixes, then preamble command, then the model (using compact Turtle) then postamble command. Leaves udpate open

close

public void close()

Finish the update command, capturing the result status and any return message

getStatus

public int getStatus()

Get the returned status code from the request

getResponseMessage

public String getResponseMessage()

Get the message part of the HTTP response, generally not interesting

getResponseBody

public String getResponseBody()

Get the body of the HTTP response, in the event of an error response the server may return useful human readable information in the body. May be null if the there was no response body (e.g. 204 return)

wasSuccessful

public boolean wasSuccessful()

Return true if the update succeeded (response code 2xx or 3xx)

Returns: