lang/java/reef-webserver/src/main/java/org/apache/reef/webserver/AvroHttpSerializer.java

/*
 * 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 org.apache.reef.webserver;

import org.apache.avro.file.DataFileReader;
import org.apache.avro.file.DataFileWriter;
import org.apache.avro.io.*;
import org.apache.avro.specific.SpecificDatumReader;
import org.apache.avro.specific.SpecificDatumWriter;

import javax.servlet.ServletException;
import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.IOException;
import java.nio.ByteBuffer;
import java.util.*;

/**
 * Serialize Http Request Response data with Avro.
 */
public class AvroHttpSerializer {

  public static final String JSON_CHARSET = "ISO-8859-1";

  public AvroHttpSerializer() {
  }

  /**
   * Convert from HttpServletRequest to AvroHttpRequest.
   */
  public AvroHttpRequest toAvro(final ParsedHttpRequest parsedRequest) throws ServletException, IOException {

    return AvroHttpRequest.newBuilder()
        .setRequestUrl(parsedRequest.getRequestUrl())
        .setHttpMethod(parsedRequest.getMethod())
        .setQueryString(parsedRequest.getQueryString())
        .setPathInfo(parsedRequest.getPathInfo())
        .setInputStream(ByteBuffer.wrap(parsedRequest.getInputStream()))
        .setHeader(parsedRequest.getHeaderEntryList())
        .build();
  }

  /**
   * Convert AvroHttpRequest to JSON String.
   */
  public String toString(final AvroHttpRequest request) {
    final DatumWriter<AvroHttpRequest> configurationWriter = new SpecificDatumWriter<>(AvroHttpRequest.class);
    try (ByteArrayOutputStream out = new ByteArrayOutputStream()) {
      final JsonEncoder encoder = EncoderFactory.get().jsonEncoder(AvroHttpRequest.SCHEMA$, out);
      configurationWriter.write(request, encoder);
      encoder.flush();
      return out.toString(JSON_CHARSET);
    } catch (final IOException e) {
      throw new RuntimeException(e);
    }
  }

  /**
   * Convert AvroHttpRequest to bytes.
   */
  public byte[] toBytes(final AvroHttpRequest request) {
    final DatumWriter<AvroHttpRequest> requestWriter = new SpecificDatumWriter<>(AvroHttpRequest.class);
    try (ByteArrayOutputStream out = new ByteArrayOutputStream()) {
      final BinaryEncoder encoder = EncoderFactory.get().binaryEncoder(out, null);
      requestWriter.write(request, encoder);
      encoder.flush();
      return out.toByteArray();
    } catch (final IOException e) {
      throw new RuntimeException(e);
    }
  }

  /**
   * Conver AvroHttpRequest to a file.
   * @param avroHttpRequest
   * @param file
   * @throws IOException
   * @throws ServletException
   */
  public void toFile(final AvroHttpRequest avroHttpRequest, final File file) throws IOException, ServletException {
    final DatumWriter<AvroHttpRequest> httpWriter = new SpecificDatumWriter<>(AvroHttpRequest.class);
    try (DataFileWriter<AvroHttpRequest> dataFileWriter = new DataFileWriter<>(httpWriter)) {
      dataFileWriter.create(avroHttpRequest.getSchema(), file);
      dataFileWriter.append(avroHttpRequest);
    }
  }

  /**
   * Convert a file to AvroHttpRequest.
   * @param file
   * @return
   * @throws IOException
   */
  public AvroHttpRequest fromFile(final File file) throws IOException {
    final AvroHttpRequest avrohttpRequest;
    try (DataFileReader<AvroHttpRequest> dataFileReader =
                 new DataFileReader<>(file, new SpecificDatumReader<>(AvroHttpRequest.class))) {
      avrohttpRequest = dataFileReader.next();
    }
    return avrohttpRequest;
  }

  /**
   * Convert JSON String to AvroHttpRequest.
   */
  public AvroHttpRequest fromString(final String jasonStr) {
    try {
      final JsonDecoder decoder = DecoderFactory.get().jsonDecoder(AvroHttpRequest.getClassSchema(), jasonStr);
      final SpecificDatumReader<AvroHttpRequest> reader = new SpecificDatumReader<>(AvroHttpRequest.class);
      return reader.read(null, decoder);
    } catch (final IOException e) {
      throw new RuntimeException(e);
    }
  }

  /**
   * Convert bytes to AvroHttpRequest.
   */
  public AvroHttpRequest fromBytes(final byte[] theBytes) {
    try {
      final BinaryDecoder decoder = DecoderFactory.get().binaryDecoder(theBytes, null);
      final SpecificDatumReader<AvroHttpRequest> reader = new SpecificDatumReader<>(AvroHttpRequest.class);
      return reader.read(null, decoder);
    } catch (final IOException e) {
      throw new RuntimeException(e);
    }
  }
}