opennlp.tools.postag.POSModel.java Source code

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Here is the source code for opennlp.tools.postag.POSModel.java

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/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License. You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package opennlp.tools.postag;

import java.io.File;
import java.io.IOException;
import java.io.InputStream;
import java.net.URL;
import java.nio.file.Path;
import java.util.Map;
import java.util.Objects;
import java.util.Properties;

import opennlp.tools.dictionary.Dictionary;
import opennlp.tools.ml.BeamSearch;
import opennlp.tools.ml.model.MaxentModel;
import opennlp.tools.ml.model.SequenceClassificationModel;
import opennlp.tools.util.BaseToolFactory;
import opennlp.tools.util.InvalidFormatException;
import opennlp.tools.util.model.ArtifactSerializer;
import opennlp.tools.util.model.BaseModel;
import opennlp.tools.util.model.ByteArraySerializer;
import opennlp.tools.util.model.POSModelSerializer;
import opennlp.tools.util.model.SerializableArtifact;

/**
 * The {@link POSModel} is the model used
 * by a learnable {@link POSTagger}.
 *
 * @see POSTaggerME
 */
public final class POSModel extends BaseModel implements SerializableArtifact {

    private static final String COMPONENT_NAME = "POSTaggerME";
    static final String POS_MODEL_ENTRY_NAME = "pos.model";
    static final String GENERATOR_DESCRIPTOR_ENTRY_NAME = "generator.featuregen";

    public POSModel(String languageCode, SequenceClassificationModel<String> posModel,
            Map<String, String> manifestInfoEntries, POSTaggerFactory posFactory) {

        super(COMPONENT_NAME, languageCode, manifestInfoEntries, posFactory);

        artifactMap.put(POS_MODEL_ENTRY_NAME, Objects.requireNonNull(posModel, "posModel must not be null"));

        artifactMap.put(GENERATOR_DESCRIPTOR_ENTRY_NAME, posFactory.getFeatureGenerator());

        for (Map.Entry<String, Object> resource : posFactory.getResources().entrySet()) {
            artifactMap.put(resource.getKey(), resource.getValue());
        }

        // TODO: This fails probably for the sequence model ... ?!
        // checkArtifactMap();
    }

    public POSModel(String languageCode, MaxentModel posModel, Map<String, String> manifestInfoEntries,
            POSTaggerFactory posFactory) {
        this(languageCode, posModel, POSTaggerME.DEFAULT_BEAM_SIZE, manifestInfoEntries, posFactory);
    }

    public POSModel(String languageCode, MaxentModel posModel, int beamSize,
            Map<String, String> manifestInfoEntries, POSTaggerFactory posFactory) {

        super(COMPONENT_NAME, languageCode, manifestInfoEntries, posFactory);

        Objects.requireNonNull(posModel, "posModel must not be null");

        Properties manifest = (Properties) artifactMap.get(MANIFEST_ENTRY);
        manifest.setProperty(BeamSearch.BEAM_SIZE_PARAMETER, Integer.toString(beamSize));

        artifactMap.put(POS_MODEL_ENTRY_NAME, posModel);
        artifactMap.put(GENERATOR_DESCRIPTOR_ENTRY_NAME, posFactory.getFeatureGenerator());

        for (Map.Entry<String, Object> resource : posFactory.getResources().entrySet()) {
            artifactMap.put(resource.getKey(), resource.getValue());
        }

        checkArtifactMap();
    }

    public POSModel(InputStream in) throws IOException {
        super(COMPONENT_NAME, in);
    }

    public POSModel(File modelFile) throws IOException {
        super(COMPONENT_NAME, modelFile);
    }

    public POSModel(Path modelPath) throws IOException {
        this(modelPath.toFile());
    }

    public POSModel(URL modelURL) throws IOException {
        super(COMPONENT_NAME, modelURL);
    }

    @Override
    protected Class<? extends BaseToolFactory> getDefaultFactory() {
        return POSTaggerFactory.class;
    }

    @Override
    protected void validateArtifactMap() throws InvalidFormatException {
        super.validateArtifactMap();

        if (!(artifactMap.get(POS_MODEL_ENTRY_NAME) instanceof MaxentModel)) {
            throw new InvalidFormatException("POS model is incomplete!");
        }
    }

    /**
     * @deprecated use getPosSequenceModel instead. This method will be removed soon.
     * Only required for Parser 1.5.x backward compatibility. Newer models don't need this anymore.
     */
    @Deprecated
    public MaxentModel getPosModel() {
        if (artifactMap.get(POS_MODEL_ENTRY_NAME) instanceof MaxentModel) {
            return (MaxentModel) artifactMap.get(POS_MODEL_ENTRY_NAME);
        } else {
            return null;
        }
    }

    public SequenceClassificationModel<String> getPosSequenceModel() {

        Properties manifest = (Properties) artifactMap.get(MANIFEST_ENTRY);

        if (artifactMap.get(POS_MODEL_ENTRY_NAME) instanceof MaxentModel) {
            String beamSizeString = manifest.getProperty(BeamSearch.BEAM_SIZE_PARAMETER);

            int beamSize = POSTaggerME.DEFAULT_BEAM_SIZE;
            if (beamSizeString != null) {
                beamSize = Integer.parseInt(beamSizeString);
            }

            return new BeamSearch<>(beamSize, (MaxentModel) artifactMap.get(POS_MODEL_ENTRY_NAME));
        } else if (artifactMap.get(POS_MODEL_ENTRY_NAME) instanceof SequenceClassificationModel) {
            return (SequenceClassificationModel) artifactMap.get(POS_MODEL_ENTRY_NAME);
        } else {
            return null;
        }
    }

    public POSTaggerFactory getFactory() {
        return (POSTaggerFactory) this.toolFactory;
    }

    @Override
    protected void createArtifactSerializers(Map<String, ArtifactSerializer> serializers) {
        super.createArtifactSerializers(serializers);

        serializers.put("featuregen", new ByteArraySerializer());
    }

    /**
     * Retrieves the ngram dictionary.
     *
     * @return ngram dictionary or null if not used
     */
    public Dictionary getNgramDictionary() {
        if (getFactory() != null)
            return getFactory().getDictionary();
        return null;
    }

    @Override
    public Class<POSModelSerializer> getArtifactSerializerClass() {
        return POSModelSerializer.class;
    }
}