content: /*
   * The Alluxio Open Foundation licenses this work under the Apache License, version 2.0
   * (the "License"). You may not use this work except in compliance with the License, which is
   * available at www.apache.org/licenses/LICENSE-2.0
   *
   * This software is distributed on an "AS IS" basis, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND,
   * either express or implied, as more fully set forth in the License.
   *
   * See the NOTICE file distributed with this work for information regarding copyright ownership.
   */
  
  package alluxio.cli.fs.command;
  
  import alluxio.AlluxioURI;
  import alluxio.cli.Command;
  import alluxio.cli.fs.FileSystemShellUtils;
  import alluxio.client.file.FileSystem;
  import alluxio.client.file.FileSystemContext;
  import alluxio.exception.AlluxioException;
  
  import com.google.common.base.Joiner;
  import org.apache.commons.cli.CommandLine;
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  
  import java.io.IOException;
  import java.util.ArrayList;
  import java.util.Comparator;
  import java.util.List;
  import javax.annotation.Nullable;
  import javax.annotation.concurrent.ThreadSafe;
  
  /**
   * The base class for all the FileSystem {@link alluxio.cli.Command} classes.
   * It provides a place to hold the {@link FileSystem} client.
   */
  @ThreadSafe
  public abstract class AbstractFileSystemCommand implements Command {
    private static final Logger LOG = LoggerFactory.getLogger(AbstractFileSystemCommand.class);
  
    protected FileSystem mFileSystem;
    protected FileSystemContext mFsContext;
  
    // The FilesystemContext contains configuration information and is also used to instantiate a
    // filesystem client, if null - load default properties
    protected AbstractFileSystemCommand(@Nullable FileSystemContext fsContext) {
      if (fsContext == null) {
        fsContext = FileSystemContext.create();
      }
      mFsContext = fsContext;
      mFileSystem = FileSystem.Factory.create(fsContext);
    }
  
    /**
     * Runs the command for a particular URI that does not contain wildcard in its path.
     *
     * @param plainPath an AlluxioURI that does not contain wildcard
     * @param cl object containing the original commandLine
     */
    protected void runPlainPath(AlluxioURI plainPath, CommandLine cl)
        throws AlluxioException, IOException {
    }
  
    /**
     * Processes the header of the command. Our input path may contain wildcard
     * but we only want to print the header for once.
     *
     * @param cl object containing the original commandLine
     */
    protected void processHeader(CommandLine cl) throws IOException {
    }
  
    /**
     * Runs the command for a particular URI that may contain wildcard in its path.
     *
     * @param wildCardPath an AlluxioURI that may or may not contain a wildcard
     * @param cl object containing the original commandLine
     */
    protected void runWildCardCmd(AlluxioURI wildCardPath, CommandLine cl) throws IOException {
      List<AlluxioURI> paths = FileSystemShellUtils.getAlluxioURIs(mFileSystem, wildCardPath);
      if (paths.size() == 0) { // A unified sanity check on the paths
        throw new IOException(wildCardPath + " does not exist.");
      }
      paths.sort(Comparator.comparing(AlluxioURI::getPath));
  
      // TODO(lu) if errors occur in runPlainPath, we may not want to print header
      processHeader(cl);
  
      List<String> errorMessages = new ArrayList<>();
      for (AlluxioURI path : paths) {
        try {
          runPlainPath(path, cl);
        } catch (AlluxioException | IOException e) {
          LOG.error(String.format("error processing path: %s", path), e);
          errorMessages.add(e.getMessage() != null ? e.getMessage() : e.toString());
        }
      }
  
      if (errorMessages.size() != 0) {
        throw new IOException(Joiner.on('\n').join(errorMessages));
      }
    }
  }
  