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POHow to use REST endpoint to work with neo4j SPARQLPlugin
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copied!<p>I am trying to run "SPARQLPlugin" with the neo4j 2.0 M06, on a newly installed folder with no data in the database, but I am unable to find an example as to how I can call the REST endpoint. Is there an example somewhere that shows how the rest endpoint can be used play with SPARQL?</p> <p>I am trying with the chrome Advanced rest client as shown below <img src="https://i.stack.imgur.com/JNjC2.jpg" alt="POST Call with the example data"></p> <p>i get an error response as below:</p> <pre><code>{ "message" : "java.lang.String cannot be cast to java.util.Map", "exception" : "BadInputException", "fullname" : "org.neo4j.server.rest.repr.BadInputException", "stacktrace" : [ "org.neo4j.server.rest.repr.formats.JsonFormat.readMap(JsonFormat.java:92)", "org.neo4j.server.rest.repr.RepresentationFormat.readParameterList(RepresentationFormat.java:97)", "org.neo4j.server.rest.web.ExtensionService.invokeGraphDatabaseExtension(ExtensionService.java:134)", "java.lang.reflect.Method.invoke(Unknown Source)", "org.neo4j.server.rest.transactional.TransactionalRequestDispatcher.dispatch(TransactionalRequestDispatcher.java:132)", "org.neo4j.server.rest.security.SecurityFilter.doFilter(SecurityFilter.java:112)", "java.lang.Thread.run(Unknown Source)" ], "cause" : { "message" : "java.lang.String cannot be cast to java.util.Map", "exception" : "ClassCastException", "stacktrace" : [ "org.neo4j.server.rest.domain.JsonHelper.jsonToMap(JsonHelper.java:53)", "org.neo4j.server.rest.repr.formats.JsonFormat.readMap(JsonFormat.java:88)", "org.neo4j.server.rest.repr.RepresentationFormat.readParameterList(RepresentationFormat.java:97)", "org.neo4j.server.rest.web.ExtensionService.invokeGraphDatabaseExtension(ExtensionService.java:134)", "java.lang.reflect.Method.invoke(Unknown Source)", "org.neo4j.server.rest.transactional.TransactionalRequestDispatcher.dispatch(TransactionalRequestDispatcher.java:132)", "org.neo4j.server.rest.security.SecurityFilter.doFilter(SecurityFilter.java:112)", "java.lang.Thread.run(Unknown Source)" ], "fullname" : "java.lang.ClassCastException" } } </code></pre> <p>I have checked that the plugin is loaded in the neo4j and its also throwing error when i do something silly, so I assume that its working. So really looking forward to see how this can be used.</p> <p><strong>EDIT:</strong> </p> <p>As suggested below here is the stack trace when I include the { } around my payload where I get <strong>500</strong> status back</p> <pre><code> { "message" : "com/tinkerpop/blueprints/impls/neo4j/Neo4jGraph", "exception" : "NoClassDefFoundError", "fullname" : "java.lang.NoClassDefFoundError", "stacktrace" : [ "org.neo4j.server.plugin.sparql.SPARQLPlugin.initSail(SPARQLPlugin.java:90)", "org.neo4j.server.plugin.sparql.SPARQLPlugin.executeInsert(SPARQLPlugin.java:113)", "java.lang.reflect.Method.invoke(Unknown Source)", "org.neo4j.server.plugins.PluginMethod.invoke(PluginMethod.java:61)", "org.neo4j.server.plugins.PluginManager.invoke(PluginManager.java:168)", "org.neo4j.server.rest.web.ExtensionService.invokeGraphDatabaseExtension(ExtensionService.java:312)", "org.neo4j.server.rest.web.ExtensionService.invokeGraphDatabaseExtension(ExtensionService.java:134)", "java.lang.reflect.Method.invoke(Unknown Source)", "org.neo4j.server.rest.transactional.TransactionalRequestDispatcher.dispatch(TransactionalRequestDispatcher.java:132)", "org.neo4j.server.rest.security.SecurityFilter.doFilter(SecurityFilter.java:112)", "java.lang.Thread.run(Unknown Source)" ], "cause" : { "message" : "com.tinkerpop.blueprints.impls.neo4j.Neo4jGraph", "exception" : "ClassNotFoundException", "stacktrace" : [ "java.net.URLClassLoader$1.run(Unknown Source)", "java.net.URLClassLoader$1.run(Unknown Source)", "java.security.AccessController.doPrivileged(Native Method)", "java.net.URLClassLoader.findClass(Unknown Source)", "java.lang.ClassLoader.loadClass(Unknown Source)", "sun.misc.Launcher$AppClassLoader.loadClass(Unknown Source)", "java.lang.ClassLoader.loadClass(Unknown Source)", "org.neo4j.server.plugin.sparql.SPARQLPlugin.initSail(SPARQLPlugin.java:90)", "org.neo4j.server.plugin.sparql.SPARQLPlugin.executeInsert(SPARQLPlugin.java:113)", "java.lang.reflect.Method.invoke(Unknown Source)", "org.neo4j.server.plugins.PluginMethod.invoke(PluginMethod.java:61)", "org.neo4j.server.plugins.PluginManager.invoke(PluginManager.java:168)", "org.neo4j.server.rest.web.ExtensionService.invokeGraphDatabaseExtension(ExtensionService.java:312)", "org.neo4j.server.rest.web.ExtensionService.invokeGraphDatabaseExtension(ExtensionService.java:134)", "java.lang.reflect.Method.invoke(Unknown Source)", "org.neo4j.server.rest.transactional.TransactionalRequestDispatcher.dispatch(TransactionalRequestDispatcher.java:132)", "org.neo4j.server.rest.security.SecurityFilter.doFilter(SecurityFilter.java:112)", "java.lang.Thread.run(Unknown Source)" ], "fullname" : "java.lang.ClassNotFoundException" } } </code></pre> <p>I didn't include this initially assuming this to be a mistake on how I am posting the data to the endpoint.</p> <p><strong>EDIT 3</strong></p> <p>I tried to build the plugin again (using "mvn package -DskipTests" as tests were failing) this time pointing it to 2.4.0 of blueprint in the plugin pom.xml and downloaded the correct version of missing blueprints-neo4j-graph-2.4.0.jar for blueprint. after that i see a new error, but looks like its getting closer this time, may be some version mismatch again. any idea what this is? </p> <pre><code>{ "message" : "org.neo4j.kernel.impl.core.NodeManager.getGraphProperties()Lorg/neo4j/kernel/impl/core/GraphProperties;", "exception" : "NoSuchMethodError", "fullname" : "java.lang.NoSuchMethodError", "stacktrace" : [ "com.tinkerpop.blueprints.impls.neo4j.Neo4jGraph.getInternalIndexKeys(Neo4jGraph.java:235)", "com.tinkerpop.blueprints.impls.neo4j.Neo4jGraph.loadKeyIndices(Neo4jGraph.java:175)", "com.tinkerpop.blueprints.impls.neo4j.Neo4jGraph.<init>(Neo4jGraph.java:140)", "com.tinkerpop.blueprints.impls.neo4j.Neo4jGraph.<init>(Neo4jGraph.java:144)", "org.neo4j.server.plugin.sparql.SPARQLPlugin.initSail(SPARQLPlugin.java:90)", "org.neo4j.server.plugin.sparql.SPARQLPlugin.executeInsert(SPARQLPlugin.java:113)", "java.lang.reflect.Method.invoke(Unknown Source)", "org.neo4j.server.plugins.PluginMethod.invoke(PluginMethod.java:61)", "org.neo4j.server.plugins.PluginManager.invoke(PluginManager.java:168)", "org.neo4j.server.rest.web.ExtensionService.invokeGraphDatabaseExtension(ExtensionService.java:312)", "org.neo4j.server.rest.web.ExtensionService.invokeGraphDatabaseExtension(ExtensionService.java:134)", "java.lang.reflect.Method.invoke(Unknown Source)", "org.neo4j.server.rest.transactional.TransactionalRequestDispatcher.dispatch(TransactionalRequestDispatcher.java:132)", "org.neo4j.server.rest.security.SecurityFilter.doFilter(SecurityFilter.java:112)", "java.lang.Thread.run(Unknown Source)" ] } </code></pre> <p>also the Query is returning a similar error:</p> <pre><code>{ "message" : "org.neo4j.kernel.impl.core.NodeManager.getGraphProperties()Lorg/neo4j/kernel/impl/core/GraphProperties;", "exception" : "NoSuchMethodError", "fullname" : "java.lang.NoSuchMethodError", "stacktrace" : [ "com.tinkerpop.blueprints.impls.neo4j.Neo4jGraph.getInternalIndexKeys(Neo4jGraph.java:235)", "com.tinkerpop.blueprints.impls.neo4j.Neo4jGraph.loadKeyIndices(Neo4jGraph.java:175)", "com.tinkerpop.blueprints.impls.neo4j.Neo4jGraph.<init>(Neo4jGraph.java:140)", "com.tinkerpop.blueprints.impls.neo4j.Neo4jGraph.<init>(Neo4jGraph.java:144)", "org.neo4j.server.plugin.sparql.SPARQLPlugin.initSail(SPARQLPlugin.java:90)", "org.neo4j.server.plugin.sparql.SPARQLPlugin.executeSPARQL(SPARQLPlugin.java:61)", "java.lang.reflect.Method.invoke(Unknown Source)", "org.neo4j.server.plugins.PluginMethod.invoke(PluginMethod.java:61)", "org.neo4j.server.plugins.PluginManager.invoke(PluginManager.java:168)", "org.neo4j.server.rest.web.ExtensionService.invokeGraphDatabaseExtension(ExtensionService.java:312)", "org.neo4j.server.rest.web.ExtensionService.invokeGraphDatabaseExtension(ExtensionService.java:134)", "java.lang.reflect.Method.invoke(Unknown Source)", "org.neo4j.server.rest.transactional.TransactionalRequestDispatcher.dispatch(TransactionalRequestDispatcher.java:132)", "org.neo4j.server.rest.security.SecurityFilter.doFilter(SecurityFilter.java:112)", "java.lang.Thread.run(Unknown Source)" ] } </code></pre> <p>Thanks, Kiran</p>

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