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.charset.StandardCharsets;
  import java.util.List;
  
  import joptsimple.OptionParser;
  
  import joptsimple.OptionSet;
  import org.apache.avro.Schema;
  import org.apache.avro.SchemaNormalization;
  
  /**
   * Utility to convert an Avro @{Schema} to its canonical form.
   */
  public class SchemaNormalizationTool implements Tool {
    @Override
    public String getName() {
      return "canonical";
    }
  
    @Override
    public String getShortDescription() {
      return "Converts an Avro Schema to its canonical form";
    }
  
    @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: infile outfile (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);
  
      Schema schema = new Schema.Parser().parse(inStream);
  
      String canonicalForm = SchemaNormalization.toParsingForm(schema);
  
      outStream.write(canonicalForm.getBytes(StandardCharsets.UTF_8));
  
      Util.close(inStream);
      Util.close(outStream);
  
      return 0;
    }
  }
  