public void writeEdgeCSVs()

in gremlin/neptune-social-media-utils/src/main/java/com/aws/neptune/utils/generator/CSVGenerator.java [146:242]
63 lines of code
14 McCabe index (conditional complexity)

    public void writeEdgeCSVs(EdgeTypeBean type, String s3Bucket, String bucketFolder ) {
        ArrayList<String> header = new ArrayList<String>();
        
        S3Uploader s3Uploader = new S3Uploader();
        
        //header.add("Left");
        //header.add("Right");
        
        //ejazs - per Amazon Neptune format
        header.add("~id");
        header.add("~label");
        header.add("~from");
        header.add("~to");
        
        IdBean ids;
        if (type.columns != null) {
            header.addAll( type.columns.keySet());
        }
        try {
            for (RelationBean relation: type.relations) {
                /*Ex: <left-label>_<edgeType>_<right-label>_edges.csv    */
                String fileName = 	String.join("_",
                                    relation.left,
                                    type.name,
                                    relation.right,
                                    "edges.csv");
                
                String filePath= "/tmp/" + fileName;
                
                CSVPrinter csvFilePrinter = new CSVPrinter(new FileWriter(filePath), csvFileFormat);
                //ejazs - printing the csv header
                csvFilePrinter.printRecord(header);
                
                IdStore idStore = new IdStore(idFactory, relation, type.multiplicity);
                for (int i = 0; i < relation.row; i++) {
                    ArrayList<Object> record = new ArrayList<Object>();
                    ids = idStore.getRandomPairIdForRelation();
                
                    //ejazs - record list will be converted/flattened to a single record
                    //adding a unique id for each relationship to the list first
                    record.add(relation.left+ids.toArrayList().get(0)+type.name+relation.right+ids.toArrayList().get(1));
                    
                    //then adding label for the relation 
                    record.add(type.name);
                    
                    //adding from and to node Ids
                    record.addAll(ids.toArrayList());
                    
                    //properties if any for the edge/relation
                    if (type.columns != null) {
                        record.addAll(generateOneRecord(type.columns));
                    }
                    csvFilePrinter.printRecord(record);
                }
                
                //add supernodes if applicable
                //these are defined only for select relations in .conf file provided as an argument
                if (relation.supernode != null){
                    int numSuperV = relation.supernode.get("vertices");
                    int numE = relation.supernode.get("edges");
                    int minId = idFactory.getMinId(relation.left);
                    if (  numSuperV > 0 && numE > 0){
                        for ( int v = minId; v < minId + numSuperV; v ++){
                            for (int e = 0; e < numE; e++){
                                ArrayList<Object> record = new ArrayList<Object>();
                                ids = idStore.getRandomIdForRelation(v);
                                
                                //ejazs- adding unique id
                                record.add(relation.left+ids.toArrayList().get(0)+type.name+relation.right+ ids.toArrayList().get(1));
                                //ejazs- adding label
                                record.add(type.name);
                                //adding from and to node Ids
                                record.addAll(ids.toArrayList());
                                //finally also appending properties on the edge/relation 
                                if (type.columns != null) {
                                    record.addAll(generateOneRecord(type.columns));
                                }
                                
                                csvFilePrinter.printRecord(record);
                            }
                        }
                    }
                }
                csvFilePrinter.close();
                
                System.out.println("Generated edge file: "+ filePath);
                
                File data = new File(filePath);
                s3Uploader.upload(data, s3Bucket, (bucketFolder == null ? fileName : bucketFolder+"/"+fileName));
                
                System.out.println("Uploaded " + filePath + " to S3 location " + s3Bucket + (bucketFolder == null ? "" : "/"+bucketFolder));
                
            }
        } catch (Exception e) {
            throw new RuntimeException(e);
        }
    }