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.File;
  import java.io.InputStream;
  import java.io.PrintStream;
  import java.net.URL;
  import java.net.URLClassLoader;
  import java.util.List;
  
  import org.apache.avro.reflect.ReflectData;
  
  /**
   * Utility to induce a schema from a class or a protocol from an interface.
   */
  public class InduceSchemaTool implements Tool {
  
    @Override
    public int run(InputStream in, PrintStream out, PrintStream err, List<String> args) throws Exception {
      if (args.size() == 0 || args.size() > 2) {
        System.err.println("Usage: [colon-delimited-classpath] classname");
        return 1;
      }
      ClassLoader classLoader = Thread.currentThread().getContextClassLoader();
      String className;
      if (args.size() == 2) {
        String classpaths = args.get(0);
        className = args.get(1);
        if (!classpaths.isEmpty()) {
          String[] paths = args.get(0).split(":");
          URL[] urls = new URL[paths.length];
          for (int i = 0; i < paths.length; ++i) {
            urls[i] = new File(paths[i]).toURI().toURL();
          }
          classLoader = URLClassLoader.newInstance(urls, classLoader);
        }
      } else {
        className = args.get(0);
      }
  
      Class<?> klass = classLoader.loadClass(className);
      if (klass.isInterface()) {
        System.out.println(ReflectData.get().getProtocol(klass).toString(true));
      } else {
        System.out.println(ReflectData.get().getSchema(klass).toString(true));
      }
      return 0;
    }
  
    @Override
    public String getName() {
      return "induce";
    }
  
    @Override
    public String getShortDescription() {
      return "Induce schema/protocol from Java class/interface via reflection.";
    }
  }
  