Java ExecutionEngine.execute方法代码示例

import org.neo4j.cypher.ExecutionEngine; //导入方法依赖的package包/类
public static boolean deleteExperiment(GraphDatabaseService graphDB, DBGraph experiment) {
    Transaction tx = graphDB.beginTx();
    try {
        ExecutionEngine engine = new ExecutionEngine( graphDB );
        ExecutionResult result = engine.execute( "START n=node(" + experiment.getCorrespondingNodeInDB().getId() +")\n" +
                "MATCH n-[r?]-()\n" +
                "WHERE ID(n) <> 0\n" +
                "DELETE n,r" );
        System.out.println(result.toString());
        tx.success();
        return true;
    } catch (Exception e) {
        return false;
    } finally {
        tx.finish();
    }
}
 

import org.neo4j.cypher.ExecutionEngine; //导入方法依赖的package包/类
/**
 * 
 * @param dbService
 * @param KG 
 */
public static void importFromN4j(GraphDatabaseService dbService, KnowledgeGraph KG) {
    ExecutionResult result;
    ExecutionEngine engine = new ExecutionEngine(dbService, StringLogger.SYSTEM);
    
    try(Transaction importDb = dbService.beginTx()) {
        result = engine.execute("start n=node(*) return n");
        scala.collection.immutable.Vector<Object> results = result.columnAs("n").toVector();
        
        for(int i = 0; i < results.length(); i++) {
            org.neo4j.graphdb.Node node = (org.neo4j.graphdb.Node) results.getElem(i, 0);
            
            switch((String) node.getProperty("type")) {
                case "HumanAgent":
                    Agent a = new HumanAgent((String) node.getProperty("name"));
                    a.setId((int) node.getProperty("id"));
                    KG.addResource(a);
                    break;
                    
                case "ArtificialAgent":
                    Agent aa = new ArtificialAgent((String) node.getProperty("name"));
                    aa.setId((int) node.getProperty("id"));
                    KG.addResource(aa);
                    break;
                    
                case "Topic":
                    Topic t = new Topic((String) node.getProperty("name"));
                    t.setId((int) node.getProperty("id"));
                    KG.addResource(t);
                    break;
                    
                case "Document":
                    Document d = new Document((String) node.getProperty("name"));
                    d.setId((int) node.getProperty("id"));
                    KG.addResource(d);
                    break;
            }
            
            if(((String) node.getProperty("type")).contains("Viewpoint")) {
                ConnectedViewpoint v;
                Agent emitter = null;
                ArrayList<Resource> o = new ArrayList<>();

                Iterable<Relationship> expressesRels =  node.getRelationships(N4jEdgeType.EXPRESSES_VIEWPOINT);
                for(Relationship expressesRel : expressesRels)
                    emitter = (Agent) KG.getNamedObject((String) expressesRel.getOtherNode(node).getProperty("name"));

                Iterable<Relationship> connectorRels =  node.getRelationships(N4jEdgeType.VIEWPOINT_CONNECTOR);
                for(Relationship connectorRel : connectorRels)
                    o.add(KG.getNamedObject((String) connectorRel.getOtherNode(node).getProperty("name")));

                v = ViewpointFactory.newInstance(emitter, o.get(0), o.get(1), (String) node.getProperty("type"), ViewpointPolarity.POSITIVE);
                emitter.getPerspective().addViewpoint(v);
                v.setCorrespondingNode(node);
                KG.addViewpoint(v);
                break;
            }
            
        }
        
        importDb.success();
    }
}
 

import org.neo4j.cypher.ExecutionEngine; //导入方法依赖的package包/类
private void printGraphInfo(Neo4JConnector connector, PrintStream ps) {
    ExecutionEngine engine = new ExecutionEngine(connector.getGraphDB());
    ExecutionResult result = engine.execute("start n=node(*) return count(*)");

    ps.println("Vertices: " + result.dumpToString());

    result = engine.execute("start r=rel(*) return count(*)");

    ps.println("Edges: " + result.dumpToString());
}