com.bigdata.rdf.sail.webapp

Class TxServlet

java.lang.Object

javax.servlet.GenericServlet

javax.servlet.http.HttpServlet

com.bigdata.rdf.sail.webapp.BigdataServlet

com.bigdata.rdf.sail.webapp.BigdataRDFServlet

com.bigdata.rdf.sail.webapp.TxServlet

All Implemented Interfaces:

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

public class TxServlet
extends BigdataRDFServlet

Servlet provides a REST interface for managing stand-off read/write transaction. Given a namespace that is provisioned for read/write transactions, a client can create a transaction (obtaining an identifier for that transaction), do work with that transaction (including mutation and query), prepare the transaction, and finally commit or abort the transaction.

Transaction isolation requires that the namespace is provisioned with support for isolatable indices. See BigdataSail.Options#ISOLATABLE_INDICES. When isolation is enabled for a namespace, the updates for the namespace will be buffered by isolated indices. When a transaction prepares, the write set will be validated by comparing the modified tuples against the unisolated indices touched by the write set and looking for conflicts (revision timestamps that have been updated since the transaction start). If a conflict can not be reconciled, then the transaction will be unable to commit.

Read only transactions may also be requested in order to have snapshot isolation across a series of queries. blazegraph provides snapshot isolation for queries regardless. The use of an explicit read only transaction is only required to maintain the same snapshot across multiple queries.

See Also:

Support read/write transactions in the REST API, BigdataSail.Options#ISOLATABLE_INDICES, Serialized Form

Field Summary

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

ATTR_BLUEPRINTS, MIME_JSON, MIME_RDF_XML, MIME_SPARQL_QUERY, MIME_SPARQL_RESULTS_JSON, MIME_SPARQL_RESULTS_XML, MIME_SPARQL_UPDATE, NA, OUTPUT_FORMAT_JSON, OUTPUT_FORMAT_JSON_SHORT, OUTPUT_FORMAT_QUERY_PARAMETER, OUTPUT_FORMAT_XML, OUTPUT_FORMAT_XML_SHORT, UNDEFINED_WORKBENCH_NAMESPACE, UTF8

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
TxServlet()

Method Summary

Methods

Modifier and Type	Method and Description
protected void	doGet(javax.servlet.http.HttpServletRequest req, javax.servlet.http.HttpServletResponse resp)
protected void	doPost(javax.servlet.http.HttpServletRequest req, javax.servlet.http.HttpServletResponse resp) Methods for transaction management (create, prepare, isActive, commit, abort).

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

buildAndCommitBooleanResponse, buildAndCommitNamespaceNotFoundResponse, buildAndCommitRangeCountResponse, getNamespace, getTimestamp, isAttachment, launderThrowable, newPipedInputStream, parseBindings, sendGraph, sendProperties, toURIs

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, doHead, doOptions, 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

Constructor Detail

TxServlet

public TxServlet()

Method Detail

doPost

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

Methods for transaction management (create, prepare, isActive, commit, abort).

Overrides:

doPost in class javax.servlet.http.HttpServlet

Throws:

IOException

doGet

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

Overrides:

doGet in class javax.servlet.http.HttpServlet

Throws:

IOException