How to remove duplicates elements from JSON file using java if else?

Question

This start that is found in my codes are from my JSON file. Now that in my JSON file, i have a lot of "start" with the same name. For example in this JSON file, i have duplicates in the start (having both the content as "audi"):

{"rel": "AtLocation", "weight": 0.5, "dataset": "/d/dbpedia/en", "sources": ["/s/dbpedia/3.7"], "id": "0209765bf7185615ef242513f61ca0f61efe2a04", "features": ["audi AtLocation -", "audi - curitiba", "- AtLocation curitiba"], "end": "curitiba", "license": "/l/CC/By-SA", "uri": "/a/[AtLocation/,audi/,curitiba/]", "start": "audi", "context": "/ctx/all", "surfaceText": null}

{"rel": "AtLocation", "weight": 0.5, "dataset": "/d/dbpedia/en", "sources": ["/s/dbpedia/3.7"], "id": "5158d1cfce728efb3e42840d166ec06153a3d77d", "features": ["audi AtLocation -", "audi - ingolstadt", "- AtLocation ingolstadt"], "end": "unite_state", "license": "/l/CC/By-SA", "uri": "/a/[AtLocation/,audi/,ingolstadt/]", "start": "audi", "context": "/ctx/all", "surfaceText": null}

This is my Java codes:

String start = (String) jsonObject.get("start");  
StartVertex startV = new StartVertex(start);  
helloGraphDB.addVertex(startV);    

I doesnt want it to addVertex 2 times of the same "audi", how do i write the logic if else out?

Thank you.

Answer 1

package com.infinitegraph.samples.hellograph;

// Import all InfiniteGraph packages
import java.io.BufferedReader;
import java.io.FileReader;
import java.io.IOException;
import com.infinitegraph.*;
import org.json.simple.JSONObject;
import org.json.simple.parser.JSONParser;
import org.json.simple.parser.ParseException;
// Import SLF4J logging packages
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import com.infinitegraph.BaseVertex;
import java.util.HashMap;

public class HelloGraph
{

    public static void main(String[] args)
    {
                BufferedReader br = null;
                JSONParser parser = new JSONParser();

        // Set up logging for the HelloGraph class
        Logger logger = LoggerFactory.getLogger(HelloGraph.class);

        // Create null transaction, null graph database instance
        Transaction tx = null;
        GraphDatabase helloGraphDB = null;

        // Name for graph database and property file
        String graphDbName = "HelloGraph";
        String propertiesFileName = "HelloGraph.properties";    

        try
        {
            try
            {
                // Delete graph database if it already exists
                GraphFactory.delete(graphDbName, propertiesFileName);
            }
            catch (StorageException sE)
            {
                logger.info(sE.getMessage());
            }

            // HINT: Add code to create graph database and its contents
            // Create graph database
            logger.info("> Creating graph database ...");
            GraphFactory.create(graphDbName, propertiesFileName);

            // Open graph database
            logger.info("> Opening graph database ...");
            helloGraphDB = GraphFactory.open(graphDbName, propertiesFileName);

            // Begin transaction
            logger.info("> Starting a read/write transaction ...");
            tx = helloGraphDB.beginTransaction(AccessMode.READ_WRITE);

            //create head vertex
            HeaderVertex head = new HeaderVertex("JSON File");
            helloGraphDB.addVertex(head);

            try {
                String sCurrentLine;

                br = new BufferedReader(new FileReader("C:/Users/ji/Desktop/example3.json"));

                HashMap<String, Integer> map = new HashMap <String, Integer>();

                while ((sCurrentLine = br.readLine()) != null) {

                    Object obj;

                    try {
                        obj = parser.parse(sCurrentLine);
                        JSONObject jsonObject = (JSONObject) obj;

                        //code to create vertex
                        logger.info("> Creating Start vertices ...");     
                        String start = (String) jsonObject.get("start");
                        StartVertex startV = new StartVertex(start);
                        if (!map.containsKey(start))
                        {
                            map.put(start,1);
                            helloGraphDB.addVertex(startV); 
                        }

                        //System.out.println(end);
                        String end = (String) jsonObject.get("end");
                        EndVertex endV = new EndVertex(end);
                        helloGraphDB.addVertex(endV);

                        String rel = (String) jsonObject.get("rel");
                        //System.out.println(rel);
                        logger.info("> Creating Relationship edge ...");
                        Relationship relationship1 = new Relationship("");
                        Relationship relationship2 = new Relationship(rel);

                        // Connect edges
                        logger.info("> Connecting vertices ...");
                        startV.addEdge(relationship1, head, EdgeKind.BIDIRECTIONAL, (short) 0);
                        endV.addEdge(relationship2, startV, EdgeKind.BIDIRECTIONAL, (short) 0);

                    } catch (ParseException e) {
                        // TODO Auto-generated catch block
                        e.printStackTrace();
                    }
                }

            } catch (IOException e) {
                e.printStackTrace();
            } finally {
                try {
                    if (br != null)br.close();
                } catch (IOException ex) {
                    ex.printStackTrace();
                }
            }

            // Specify a named root for traversal
            logger.info("> Naming a root vertex ...");
            helloGraphDB.nameVertex("JSON File", head);

            // Commit to save your changes to the graph database
            logger.info("> Committing changes ...");
            tx.commit();
        }

        catch (ConfigurationException cE)
        {
            logger.warn("> Configuration Exception was thrown ... ");
            logger.error(cE.getMessage());
        }

        finally
        {
            // If the transaction was not committed, complete
            // will roll it back
            if (tx != null)
                tx.complete();
            if (helloGraphDB != null)
            {
                helloGraphDB.close();
                logger.info("> On Exit: Closed graph database");
            }
        }
    }

}

// HINT: Add class definitions for Person and Meeting classes here.
class HeaderVertex extends BaseVertex
{
    private String header;

    public HeaderVertex (String header)
    {
        setStartName(header);
    }

    public void setStartName (String header)
    {
        markModified();
        this.header = header;
    }

    public String toString()
    {
        fetch();
        return this.header;
    }
}

class StartVertex extends BaseVertex
{
    private String start;

    public StartVertex (String start)
    {
        setStartName(start);
    }

    public void setStartName (String start)
    {
        markModified();
        this.start = start;
    }

    public String toString()
    {
        fetch();
        return this.start;
    }
}

class EndVertex extends BaseVertex
{
    private String end;

    public EndVertex (String end)
    {
        setEndVertex(end);
    }

    public void setEndVertex (String end)
    {
        markModified();
        this.end = end;
    }

    public String toString()
    {
        fetch();
        return this.end;
    }
}

class Relationship extends BaseEdge
{
    private String rel;

    public Relationship (String rel)
    {
        setRelationship(rel);
    }

    public void setRelationship (String rel)
    {
        markModified();
        this.rel = rel;
    }

    public String toString()
    {
        fetch();
        return this.rel;
    }
}

Answer 2

You can also use HashMap instead of array list.

It would be more efficient than linearly checking into ArrayList.

You'll have to just check whether you have a start(eg "audi") in a HashMap,if not you can add it to the Graph and also the HashMap,if it is already there in HashMap you can skip adding it both.

String a = "{\"rel\": \"AtLocation\", \"weight\": 0.5, \"dataset\": \"/d/dbpedia/en\", \"sources\": [\"/s/dbpedia/3.7\"], \"id\": \"0209765bf7185615ef242513f61ca0f61efe2a04\", \"features\": [\"audi AtLocation -\", \"audi - curitiba\", \"- AtLocation curitiba\"], \"end\": \"curitiba\", \"license\": \"/l/CC/By-SA\", \"uri\": \"/a/[AtLocation/,audi/,curitiba/]\", \"start\": \"audi\", \"context\": \"/ctx/all\", \"surfaceText\": null}";
        String b = "{\"rel\": \"AtLocation\", \"weight\": 0.5, \"dataset\": \"/d/dbpedia/en\", \"sources\": [\"/s/dbpedia/3.7\"], \"id\": \"5158d1cfce728efb3e42840d166ec06153a3d77d\", \"features\": [\"audi AtLocation -\", \"audi - ingolstadt\", \"- AtLocation ingolstadt\"], \"end\": \"unite_state\", \"license\": \"/l/CC/By-SA\", \"uri\": \"/a/[AtLocation/,audi/,ingolstadt/]\", \"start\": \"audi\", \"context\": \"/ctx/all\", \"surfaceText\": null}";
        JSONParser p = new JSONParser();
        JSONObject jsonA = (JSONObject) p.parse( a );
        JSONObject jsonB = (JSONObject) p.parse( b );
        HashMap<String, Integer> map = new HashMap<String, Integer>();

        String start = (String) jsonA.get( "start" );
        System.out.println( "Does map contains 'audi' for start:" + map.containsKey( start ) );
        if( !map.containsKey( start ) )
        {
            map.put( start, 1 );
            System.out.println( "Adding to graph" );
        }
        System.out.println( "Does map contains 'audi' for start:" + map.containsKey( start ) );

        start = (String) jsonB.get( "start" );
        if( !map.containsKey( start ) )
        {
            map.put( start, 2 );
            System.out.println( "Adding to graph" );
        }

        System.out.println( "Does map contains 'audi' for start:" + map.containsKey( start ) );

The Output that i got:

Does map contains 'audi' for start:false
Adding to graph
Does map contains 'audi' for start:true
Does map contains 'audi' for start:true

Answer 3

`You can use arraylist to check whether the value already inserted into addVertex

Like :

ArrayList addedVertex_Val = new ArrayList();


    String start = (String) jsonObject.get("start");
    boolean shouldInsert = true;

    for (int al_length = 0; al_length < addedVertex_val.size(); al_length++) {
        String val = addedVertex_val.get(al_length).toString();
        if (val.equals(start)) {
            shouldInsert = false;
            break;
        }
    }

    if (shouldInsert) {
        StartVertex startV = new StartVertex(start);
        helloGraphDB.addVertex(startV);
        addedVertex_Val.add(startV);
    }

`