com.intropro.prairie.format.seq.SequenceFormatWriter.java Source code

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Here is the source code for com.intropro.prairie.format.seq.SequenceFormatWriter.java

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/**
 * 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 com.intropro.prairie.format.seq;

import com.intropro.prairie.format.OutputFormatWriter;
import org.apache.commons.io.IOUtils;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.io.NullWritable;
import org.apache.hadoop.io.SequenceFile;
import org.apache.hadoop.io.SequenceFile.Writer;
import org.apache.hadoop.io.Text;

import java.io.*;

/**
 * Created by presidentio on 10/11/15.
 */
public class SequenceFormatWriter implements OutputFormatWriter<String> {

    private OutputStream outputStream;
    private Writer writer;
    private Text text = new Text();
    private File tmpFile;

    SequenceFormatWriter(OutputStream outputStream) {
        this.outputStream = outputStream;
    }

    @Override
    public void write(String line) throws IOException {
        if (writer == null) {
            tmpFile = File.createTempFile("seq-", ".dat");
            writer = SequenceFile.createWriter(new Configuration(), Writer.file(new Path(tmpFile.toURI())),
                    Writer.keyClass(NullWritable.class), Writer.valueClass(Text.class));
        }
        text.set(line);
        writer.append(NullWritable.get(), text);
    }

    @Override
    public void close() throws IOException {
        writer.close();
        InputStream inputStream = new FileInputStream(tmpFile);
        IOUtils.copy(inputStream, outputStream);
        inputStream.close();
        outputStream.close();
        tmpFile.delete();
    }
}