content: /*
   * 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
   *
   *     https://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.avro.tool;
  
  import java.io.BufferedInputStream;
  import java.io.BufferedOutputStream;
  import java.io.InputStream;
  import java.io.PrintStream;
  import java.nio.ByteBuffer;
  import java.nio.charset.StandardCharsets;
  import java.util.List;
  
  import joptsimple.OptionParser;
  import joptsimple.OptionSet;
  
  import org.apache.avro.Schema;
  import org.apache.avro.file.DataFileStream;
  import org.apache.avro.generic.GenericDatumReader;
  
  /** Reads an avro data file into a plain text file. */
  public class ToTextTool implements Tool {
    private static final String TEXT_FILE_SCHEMA = "\"bytes\"";
    private static final byte[] LINE_SEPARATOR = System.getProperty("line.separator").getBytes(StandardCharsets.UTF_8);
  
    @Override
    public String getName() {
      return "totext";
    }
  
    @Override
    public String getShortDescription() {
      return "Converts an Avro data file to a text file.";
    }
  
    @Override
    public int run(InputStream stdin, PrintStream out, PrintStream err, List<String> args) throws Exception {
  
      OptionParser p = new OptionParser();
      OptionSet opts = p.parse(args.toArray(new String[0]));
      if (opts.nonOptionArguments().size() != 2) {
        err.println("Expected 2 args: from_file to_file (filenames or '-' for stdin/stdout");
        p.printHelpOn(err);
        return 1;
      }
  
      BufferedInputStream inStream = Util.fileOrStdin(args.get(0), stdin);
      BufferedOutputStream outStream = Util.fileOrStdout(args.get(1), out);
  
      GenericDatumReader<Object> reader = new GenericDatumReader<>();
      DataFileStream<Object> fileReader = new DataFileStream<>(inStream, reader);
  
      if (!fileReader.getSchema().equals(new Schema.Parser().parse(TEXT_FILE_SCHEMA))) {
        err.println("Avro file is not generic text schema");
        p.printHelpOn(err);
        fileReader.close();
        return 1;
      }
  
      while (fileReader.hasNext()) {
        ByteBuffer outBuff = (ByteBuffer) fileReader.next();
        outStream.write(outBuff.array());
        outStream.write(LINE_SEPARATOR);
      }
      fileReader.close();
      Util.close(inStream);
      Util.close(outStream);
      return 0;
    }
  
  }
  