Java example source code file (DocumentIteratorConverter.java)

This example Java source code file (DocumentIteratorConverter.java) is included in the alvinalexander.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" ^TM.

Learn more about this Java project at its project page.

Java - Java tags/keywords

bufferedreader, documentiteratorconverter, inputstreamreader, ioexception, labelawaredocumentiterator, labelawareiterator, labelleddocument, labelssource, nonnull, override, runtimeexception, string, stringbuilder

The DocumentIteratorConverter.java Java example source code

package org.deeplearning4j.text.documentiterator.interoperability;

import lombok.NonNull;
import org.deeplearning4j.text.documentiterator.*;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;

/**
 * Simple class providing compatibility between DocumentIterator/LabelAwareDocumentIterator and LabelAwareIterator
 *
 * @author raver119@gmail.com
 */
public class DocumentIteratorConverter implements LabelAwareIterator {

    protected DocumentIterator backendIterator;
    protected LabelsSource generator;

    public DocumentIteratorConverter(@NonNull LabelAwareDocumentIterator iterator) {
        this.backendIterator = iterator;
    }

    public DocumentIteratorConverter(@NonNull DocumentIterator iterator, @NonNull LabelsSource generator) {
        this.backendIterator = iterator;
        this.generator = generator;
    }

    @Override
    public boolean hasNextDocument() {
        return backendIterator.hasNext();
    }

    @Override
    public LabelledDocument nextDocument() {
        try {
            LabelledDocument document = new LabelledDocument();

            document.setContent(readStream(backendIterator.nextDocument()));

            if (backendIterator instanceof LabelAwareDocumentIterator) {
                String currentLabel = ((LabelAwareDocumentIterator) backendIterator).currentLabel();
                document.setLabel(currentLabel);
                generator.storeLabel(currentLabel);
            } else document.setLabel(generator.nextLabel());

            return document;
        } catch (Exception e) {
            // we just publish caught exception, no magic or automation here
            throw new RuntimeException(e);
        }
    }

    @Override
    public void reset() {
        generator.reset();
        backendIterator.reset();
    }

    @Override
    public LabelsSource getLabelsSource() {
        return generator;
    }

    protected String readStream(InputStream stream) throws IOException {
        StringBuilder builder = new StringBuilder();

        BufferedReader reader = new BufferedReader(new InputStreamReader(stream));
        String line = "";
        while ((line = reader.readLine()) != null) {
            builder.append(line);
        }
        return builder.toString();
    }
}