Registry.java

/**
 * Copyright 2013 ARRIS, Inc.
 *
 * 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 parquet.tools.command;

import java.util.LinkedHashMap;
import java.util.Map;

public final class Registry {
  public static Map<String,Class<? extends Command>> registry;

  static {
    registry = new LinkedHashMap<String,Class<? extends Command>>();
    registry.put("cat", CatCommand.class);
    registry.put("head", HeadCommand.class);
    registry.put("schema", ShowSchemaCommand.class);
    registry.put("meta", ShowMetaCommand.class);
    registry.put("dump", DumpCommand.class);
  }

  public static Map<String,Command> allCommands() {
    Map<String,Command> results = new LinkedHashMap<String,Command>();
    for (Map.Entry<String,Class<? extends Command>> entry : registry.entrySet()) {
      try {
        results.put(entry.getKey(), entry.getValue().newInstance());
      } catch (Throwable th) {
      }
    }

    return results;
  }

  public static Command getCommandByName(String name) {
    Class<? extends Command> clazz = registry.get(name);
    if (clazz == null) {
      return null;
    }

    try {
      return clazz.newInstance();
    } catch (Throwable th) {
      return null;
    }
  }
}