com.bigdata.rdf.sail.webapp

Class BigdataRDFServlet

java.lang.Object

javax.servlet.GenericServlet

javax.servlet.http.HttpServlet

com.bigdata.rdf.sail.webapp.BigdataServlet

com.bigdata.rdf.sail.webapp.BigdataRDFServlet

All Implemented Interfaces:

IMimeTypes, Serializable, javax.servlet.Servlet, javax.servlet.ServletConfig

Direct Known Subclasses:

BackupServlet, BlueprintsServletProxy, DataLoaderServlet, DeleteServlet, DescribeCacheServlet, InsertServlet, MapgraphServletProxy, MultiTenancyServlet, QueryServlet, RESTServlet, StatusServlet, TxServlet, UpdateServlet, WorkbenchServlet

public abstract class BigdataRDFServlet
extends BigdataServlet

Abstract base class for Servlets which interact with the bigdata RDF data and/or SPARQL query layers.

Author:

Bryan Thompson

See Also:

Serialized Form

Field Summary

Fields

Modifier and Type	Field and Description
static String	ATTR_BLUEPRINTS Flag to signify a blueprints operation.
static String	MIME_JSON
static String	MIME_RDF_XML RDF/XML.
static String	MIME_SPARQL_QUERY
static String	MIME_SPARQL_RESULTS_JSON A SPARQL results set in JSON.
static String	MIME_SPARQL_RESULTS_XML A SPARQL results set in XML.
static String	MIME_SPARQL_UPDATE
protected static String	NA
static String	OUTPUT_FORMAT_JSON
static String	OUTPUT_FORMAT_JSON_SHORT
static String	OUTPUT_FORMAT_QUERY_PARAMETER
static String	OUTPUT_FORMAT_XML
static String	OUTPUT_FORMAT_XML_SHORT
static String	UNDEFINED_WORKBENCH_NAMESPACE
protected static String	UTF8 The name of the UTF-8 character encoding.

Fields inherited from class com.bigdata.rdf.sail.webapp.BigdataServlet

ATTRIBUTE_RDF_CONTEXT, charset, DELETE, GET, HTTP_BADREQUEST, HTTP_HEADER_BIGDATA_READ_ONLY, HTTP_INTERNALERROR, HTTP_METHOD_NOT_ALLOWED, HTTP_NOTFOUND, HTTP_NOTIMPLEMENTED, HTTP_OK, POST, PUT

Fields inherited from interface com.bigdata.rdf.sail.webapp.client.IMimeTypes

MIME_APPLICATION_JSON, MIME_APPLICATION_URL_ENCODED, MIME_APPLICATION_XML, MIME_DEFAULT_BINARY, MIME_GRAPH_ML, MIME_PROPERTIES_XML, MIME_TEXT_HTML, MIME_TEXT_JAVASCRIPT, MIME_TEXT_PLAIN

Constructor Summary

Constructors

Constructor and Description
BigdataRDFServlet()

Method Summary

Methods

Modifier and Type	Method and Description
protected static void	buildAndCommitBooleanResponse(javax.servlet.http.HttpServletResponse resp, boolean result, long elapsed) Report an boolean response and elapsed time back to the user agent.
protected void	buildAndCommitNamespaceNotFoundResponse(javax.servlet.http.HttpServletRequest req, javax.servlet.http.HttpServletResponse resp) Report that a namespace is not found.
protected static void	buildAndCommitRangeCountResponse(javax.servlet.http.HttpServletResponse resp, long rangeCount, long elapsed) Report an access path range count and elapsed time back to the user agent.
protected String	getNamespace(javax.servlet.http.HttpServletRequest req) Return the namespace which will be used to execute the query.
protected long	getTimestamp(javax.servlet.http.HttpServletRequest req) Return the timestamp which will be used to execute the query.
protected static boolean	isAttachment(String mimeType) Return true if the Content-disposition header should be set to indicate that the response body should be handled as an attachment rather than presented inline.
static void	launderThrowable(Throwable t, javax.servlet.http.HttpServletResponse resp, String queryStr) Best effort to write the stack trace onto the output stream so it will show up in the HTTP response.
protected static PipedInputStream	newPipedInputStream(PipedOutputStream os) Factory for the PipedInputStream.
protected Map<String,org.openrdf.model.Value>	parseBindings(javax.servlet.http.HttpServletRequest req, javax.servlet.http.HttpServletResponse resp) Parses query parameter bindings for validity to provide client with meaningful response.
static void	sendGraph(javax.servlet.http.HttpServletRequest req, javax.servlet.http.HttpServletResponse resp, org.openrdf.model.Graph g) Send an RDF Graph as a response using content negotiation.
protected static void	sendProperties(javax.servlet.http.HttpServletRequest req, javax.servlet.http.HttpServletResponse resp, Properties properties) Send a properties file as a response using content negotiation.
protected static org.openrdf.model.Resource[]	toURIs(String[] s) Convert an array of URI strings to an array of URIs.

Methods inherited from class com.bigdata.rdf.sail.webapp.BigdataServlet

buildAndCommitResponse, decodeContexts, getBigdataRDFContext, getBooleanValue, getIndexManager, getIndexManager, getServiceURIs, readFully, submitApiTask

Methods inherited from class javax.servlet.http.HttpServlet

doDelete, doGet, doHead, doOptions, doPost, doPut, doTrace, getLastModified, service, service

Methods inherited from class javax.servlet.GenericServlet

destroy, getInitParameter, getInitParameterNames, getServletConfig, getServletContext, getServletInfo, getServletName, init, init, log, log

Methods inherited from class java.lang.Object

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

Field Detail

UTF8

protected static final String UTF8

The name of the UTF-8 character encoding.

See Also:

Constant Field Values

NA

protected static final String NA

See Also:

Constant Field Values

MIME_SPARQL_RESULTS_XML

public static final transient String MIME_SPARQL_RESULTS_XML

A SPARQL results set in XML.

See Also:

http://www.w3.org/TR/rdf-sparql-XMLres/, Constant Field Values

MIME_SPARQL_RESULTS_JSON

public static final transient String MIME_SPARQL_RESULTS_JSON

A SPARQL results set in JSON.

See Also:

http://www.w3.org/TR/rdf-sparql-json-res/, Constant Field Values

MIME_RDF_XML

public static final transient String MIME_RDF_XML

RDF/XML.

See Also:

Constant Field Values

MIME_JSON

public static final String MIME_JSON

See Also:

Constant Field Values

MIME_SPARQL_QUERY

public static final String MIME_SPARQL_QUERY

See Also:

Constant Field Values

MIME_SPARQL_UPDATE

public static final String MIME_SPARQL_UPDATE

See Also:

Constant Field Values

OUTPUT_FORMAT_QUERY_PARAMETER

public static final String OUTPUT_FORMAT_QUERY_PARAMETER

See Also:

Constant Field Values

OUTPUT_FORMAT_JSON

public static final String OUTPUT_FORMAT_JSON

See Also:

Constant Field Values

OUTPUT_FORMAT_XML

public static final String OUTPUT_FORMAT_XML

See Also:

Constant Field Values

OUTPUT_FORMAT_JSON_SHORT

public static final String OUTPUT_FORMAT_JSON_SHORT

See Also:

Constant Field Values

OUTPUT_FORMAT_XML_SHORT

public static final String OUTPUT_FORMAT_XML_SHORT

See Also:

Constant Field Values

UNDEFINED_WORKBENCH_NAMESPACE

public static final String UNDEFINED_WORKBENCH_NAMESPACE

See Also:

Constant Field Values

ATTR_BLUEPRINTS

public static final transient String ATTR_BLUEPRINTS

Flag to signify a blueprints operation.

See Also:

Constant Field Values

Constructor Detail

BigdataRDFServlet

public BigdataRDFServlet()

Method Detail

launderThrowable

public static void launderThrowable(Throwable t,
                    javax.servlet.http.HttpServletResponse resp,
                    String queryStr)

Best effort to write the stack trace onto the output stream so it will show up in the HTTP response. This code path should be used iff we have already begun writing the response. Otherwise, an HTTP error status should be used instead. REST API methods that have defined HTTP status codes (e.g., for HttpServletResponse.SC_BAD_REQUEST) should verify the request before proceeding in order to satisify their API semantics.

This method is invoked as follows:

 launderThrowable(...)
 

This method MUST be invoked from the top-level where the request is handled. The servlet container may ABORT the connection if there is an attempt to write onto a closed response. This can cause EOF errors in the client.

Parameters:

t - The thrown error.

os - The stream on which the response will be written.

queryStr - The SPARQL Query -or- SPARQL Update command (if available) -or- a summary of the REST API command -or- an empty string if nothing else is more appropriate.

See Also:

LaunderThrowable should never throw an exception

getTimestamp

protected long getTimestamp(javax.servlet.http.HttpServletRequest req)

Return the timestamp which will be used to execute the query. The uri query parameter timestamp may be used to communicate the desired commit time against which the query will be issued. If that uri query parameter is not given then the default configured commit time will be used. Applications may create protocols for sharing interesting commit times as reported by IAtomicStore.commit() or by a distributed data loader (for scale-out).

See Also:

QueryServlet#ATTR_TIMESTAMP;

getNamespace

protected String getNamespace(javax.servlet.http.HttpServletRequest req)

Return the namespace which will be used to execute the query. The namespace is represented by the first component of the URI. If there is no namespace, then return the configured default namespace.

Returns:

The namespace.

See Also:

Missing URL encoding in RemoteRepositoryManager

newPipedInputStream

protected static final PipedInputStream newPipedInputStream(PipedOutputStream os)
                                                     throws IOException

Factory for the PipedInputStream.

Throws:

IOException

buildAndCommitNamespaceNotFoundResponse

protected void buildAndCommitNamespaceNotFoundResponse(javax.servlet.http.HttpServletRequest req,
                                           javax.servlet.http.HttpServletResponse resp)
                                                throws IOException

Report that a namespace is not found. The namespace is extracted from the HttpServletRequest.

Throws:

IOException

buildAndCommitRangeCountResponse

protected static void buildAndCommitRangeCountResponse(javax.servlet.http.HttpServletResponse resp,
                                    long rangeCount,
                                    long elapsed)
                                                throws IOException

Report an access path range count and elapsed time back to the user agent.

Parameters:

resp - The response.

rangeCount - The mutation count.

elapsed - The elapsed time (milliseconds).

Throws:

IOException

buildAndCommitBooleanResponse

protected static void buildAndCommitBooleanResponse(javax.servlet.http.HttpServletResponse resp,
                                 boolean result,
                                 long elapsed)
                                             throws IOException

Report an boolean response and elapsed time back to the user agent. The response is an XML document as follows.

where result is either "true" or "false";
where elapsed is the elapsed time in milliseconds for the request.

Parameters:

resp - The response.

result - The outcome of the request.

elapsed - The elapsed time (milliseconds).

Throws:

IOException

sendGraph

public static void sendGraph(javax.servlet.http.HttpServletRequest req,
             javax.servlet.http.HttpServletResponse resp,
             org.openrdf.model.Graph g)
                      throws IOException

Send an RDF Graph as a response using content negotiation.

Parameters:

req -

resp -

Throws:

IOException

sendProperties

protected static void sendProperties(javax.servlet.http.HttpServletRequest req,
                  javax.servlet.http.HttpServletResponse resp,
                  Properties properties)
                              throws IOException

Send a properties file as a response using content negotiation.

Parameters:

req -

resp -

Throws:

IOException

isAttachment

protected static boolean isAttachment(String mimeType)

Return true if the Content-disposition header should be set to indicate that the response body should be handled as an attachment rather than presented inline. This is just a hint to the user agent. How the user agent handles this hint is up to it.

Parameters:

mimeType - The mime type.

Returns:

true if it should be handled as an attachment.

toURIs

protected static org.openrdf.model.Resource[] toURIs(String[] s)

Convert an array of URI strings to an array of URIs.

parseBindings

protected Map<String,org.openrdf.model.Value> parseBindings(javax.servlet.http.HttpServletRequest req,
                                                javax.servlet.http.HttpServletResponse resp)
                                                     throws IOException

Parses query parameter bindings for validity to provide client with meaningful response.

Parameters:

req -

resp -

Returns:

parsed bindings -or- null if there was an error processing the bindings, in which case the response was already committed.

Throws:

IOException