org.openstreetmap.atlas.streaming.readers.CsvReader Maven / Gradle / Ivy

Go to download

Show more of this group Show more artifacts with this name
Show all versions of atlas Show documentation

"Library to load OSM data into an Atlas format"

There is a newer version: 7.0.8

package org.openstreetmap.atlas.streaming.readers;

import java.util.Iterator;

import org.openstreetmap.atlas.streaming.resource.AbstractResource;
import org.openstreetmap.atlas.streaming.resource.Resource;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/**
 * Reader for a Csv {@link Resource}. This is using openCsv
 *
 * @author tony
 * @author matthieun
 */
public class CsvReader implements Iterator
{
    public static final Logger logger = LoggerFactory.getLogger(CsvReader.class);

    private final String comment;
    private final Iterator lineIterator;
    private final CsvSchema schema;

    public CsvReader(final CsvSchema schema, final AbstractResource resource)
    {
        this.lineIterator = resource.lines().iterator();
        this.schema = schema;
        this.comment = "#";
    }

    /**
     * @param resource
     *            The resource to read
     * @param schema
     *            The Csv schema to use
     * @param comment
     *            The lines starting with this will be ignored.
     */
    public CsvReader(final CsvSchema schema, final AbstractResource resource, final String comment)
    {
        this.lineIterator = resource.lines().iterator();
        this.schema = schema;
        this.comment = comment;
    }

    @Override
    public boolean hasNext()
    {
        return this.lineIterator.hasNext();
    }

    @Override
    public CsvLine next()
    {
        CsvLine result = null;
        String candidate;

        do
        {
            candidate = this.lineIterator.next();
            if (candidate == null)
            {
                return null;
            }
            result = candidate.startsWith(this.comment) ? null : parse(candidate);
        }
        while (this.lineIterator.hasNext() && result == null);

        return result;
    }

    private CsvLine parse(final String candidate)
    {
        try
        {
            return CsvLine.build(this.schema, candidate);
        }
        catch (final Exception e)
        {
            logger.warn("Ignoring malformed line: -- {} --. Reason: {}", candidate, e.getMessage(),
                    e);
            return null;
        }
    }
}