shell/src/main/java/org/apache/accumulo/shell/commands/NamespacesCommand.java

/*
 * 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
 *
 *     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.apache.accumulo.shell.commands;

import java.io.IOException;
import java.util.Iterator;
import java.util.Map;
import java.util.TreeMap;

import org.apache.accumulo.core.client.AccumuloException;
import org.apache.accumulo.core.client.AccumuloSecurityException;
import org.apache.accumulo.core.client.impl.Namespaces;
import org.apache.accumulo.shell.Shell;
import org.apache.accumulo.shell.Shell.Command;
import org.apache.commons.cli.CommandLine;
import org.apache.commons.cli.Option;
import org.apache.commons.cli.Options;

import com.google.common.collect.Iterators;

public class NamespacesCommand extends Command {
  private Option disablePaginationOpt, namespaceIdOption;

  private static final String DEFAULT_NAMESPACE_DISPLAY_NAME = "\"\"";

  @Override
  public int execute(final String fullCommand, final CommandLine cl, final Shell shellState) throws AccumuloException, AccumuloSecurityException, IOException {
    Map<String,String> namespaces = new TreeMap<>(shellState.getConnector().namespaceOperations().namespaceIdMap());

    Iterator<String> it = Iterators.transform(namespaces.entrySet().iterator(), entry -> {
      String name = entry.getKey();
      if (Namespaces.DEFAULT_NAMESPACE.equals(name))
        name = DEFAULT_NAMESPACE_DISPLAY_NAME;
      String id = entry.getValue();
      if (cl.hasOption(namespaceIdOption.getOpt()))
        return String.format(TablesCommand.NAME_AND_ID_FORMAT, name, id);
      else
        return name;
    });

    shellState.printLines(it, !cl.hasOption(disablePaginationOpt.getOpt()));
    return 0;
  }

  @Override
  public String description() {
    return "displays a list of all existing namespaces";
  }

  @Override
  public Options getOptions() {
    final Options o = new Options();
    namespaceIdOption = new Option("l", "list-ids", false, "display internal namespace ids along with the name");
    o.addOption(namespaceIdOption);
    disablePaginationOpt = new Option("np", "no-pagination", false, "disable pagination of output");
    o.addOption(disablePaginationOpt);
    return o;
  }

  @Override
  public int numArgs() {
    return 0;
  }
}