/*
    * junixsocket
    *
    * Copyright 2009-2024 Christian Kohlschütter
    *
    * 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 org.newsclub.net.unix.demo.rmi.fd;
  
  import java.io.File;
  import java.io.FileInputStream;
  import java.io.IOException;
  import java.rmi.NotBoundException;
  import java.rmi.registry.Registry;
  
  import org.newsclub.net.unix.demo.rmi.services.StreamService;
  import org.newsclub.net.unix.rmi.AFNaming;
  import org.newsclub.net.unix.rmi.AFUNIXNaming;
  import org.newsclub.net.unix.rmi.RemoteCloseable;
  import org.newsclub.net.unix.rmi.RemoteFileInput;
  
  /**
   * Demonstrates how to read files via FileDescriptors that are exchanged via RMI.
   *
   * @author Christian Kohlschütter
   * @see StreamServer
   */
  public final class StreamClient {
    private StreamClient() {
      throw new IllegalStateException("No instances");
    }
  
    /**
     * {@link StreamClient} command-line tool.
     *
     * @param args Command-line arguments.
     * @throws IOException on error.
     * @throws NotBoundException if the server cannot be reached.
     */
    public static void main(String[] args) throws IOException, NotBoundException {
      if (args.length != 1) {
        System.err.println("Usage: StreamClient <path-to-file>");
        System.exit(1); // NOPMD
        return;
      } else if ("--help".equals(args[0]) || "-h".equals(args[0])) {
        System.out.println("Usage: StreamClient <path-to-file>");
        System.out.println();
        System.out.println("Examples:");
        System.out.println("    StreamClient /etc/hosts");
        System.out.println("    StreamClient /etc/master.passwd");
      }
  
      AFNaming naming = AFUNIXNaming.getInstance();
  
      final Registry registry = naming.getRegistry();
      StreamService obj = (StreamService) registry.lookup("streamService");
  
      File file = new File(args[0]);
      System.out.println("Trying to read " + file);
  
      try (RemoteCloseable<RemoteFileInput> rc = obj.openForReading(file)) {
        try (RemoteFileInput rfin = rc.get(); FileInputStream fin = rfin.asFileInputStream()) {
          byte[] data = new byte[4096];
  
          int len;
          while ((len = fin.read(data)) != -1) {
            System.out.write(data, 0, len);
          }
        }
      }
    }
  }