org.apache.parquet.cli.json.AvroJsonReader.java Source code

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Here is the source code for org.apache.parquet.cli.json.AvroJsonReader.java

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/*
 * Copyright 2013 Cloudera Inc.
 *
 * Licensed 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 org.apache.parquet.cli.json;

import com.fasterxml.jackson.databind.JsonNode;
import com.google.common.base.Function;
import com.google.common.collect.Iterators;
import org.apache.parquet.cli.util.RuntimeIOException;
import org.apache.avro.Schema;
import org.apache.avro.generic.GenericData;
import javax.annotation.Nullable;
import java.io.Closeable;
import java.io.IOException;
import java.io.InputStream;
import java.util.Iterator;

public class AvroJsonReader<E> implements Iterator<E>, Iterable<E>, Closeable {

    private final GenericData model;
    private final Schema schema;
    private final InputStream stream;
    private Iterator<E> iterator;

    public AvroJsonReader(InputStream stream, Schema schema) {
        this.stream = stream;
        this.schema = schema;
        this.model = GenericData.get();
        this.iterator = Iterators.transform(AvroJson.parser(stream), new Function<JsonNode, E>() {
            @Override
            @SuppressWarnings("unchecked")
            public E apply(@Nullable JsonNode node) {
                return (E) AvroJson.convertToAvro(model, node, AvroJsonReader.this.schema);
            }
        });
    }

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

    @Override
    public E next() {
        return iterator.next();
    }

    @Override
    public void close() {
        iterator = null;
        try {
            stream.close();
        } catch (IOException e) {
            throw new RuntimeIOException("Cannot close reader", e);
        }
    }

    @Override
    public void remove() {
        throw new UnsupportedOperationException("Remove is not implemented.");
    }

    @Override
    public Iterator<E> iterator() {
        return this;
    }
}