alluxio.cli.AbstractCommand.java Source code

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Here is the source code for alluxio.cli.AbstractCommand.java

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/*
 * 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;

import alluxio.exception.ExceptionMessage;
import alluxio.exception.status.InvalidArgumentException;

import org.apache.commons.cli.CommandLine;
import org.apache.commons.cli.CommandLineParser;
import org.apache.commons.cli.DefaultParser;
import org.apache.commons.cli.Options;
import org.apache.commons.cli.ParseException;

import javax.annotation.concurrent.ThreadSafe;

/**
 * The base class for all the {@link Command} classes.
 */
@ThreadSafe
public abstract class AbstractCommand implements Command {

    protected AbstractCommand() {
    }

    /**
     * Checks if the arguments are valid.
     *
     * @param args the arguments for the command, excluding the command name and options
     * @throws InvalidArgumentException when arguments are not valid
     */
    protected void validateArgs(String... args) throws InvalidArgumentException {
        if (args.length != getNumOfArgs()) {
            throw new InvalidArgumentException(
                    ExceptionMessage.INVALID_ARGS_NUM.getMessage(getCommandName(), getNumOfArgs(), args.length));
        }
    }

    /**
     * Gets the expected number of arguments of the command.
     *
     * @return the number of arguments
     */
    protected abstract int getNumOfArgs();

    @Override
    public Options getOptions() {
        return new Options();
    }

    @Override
    public CommandLine parseAndValidateArgs(String... args) throws InvalidArgumentException {
        Options opts = getOptions();
        CommandLineParser parser = new DefaultParser();
        CommandLine cmd;

        try {
            cmd = parser.parse(opts, args);
        } catch (ParseException e) {
            throw new InvalidArgumentException(String.format("Failed to parse args for %s", getCommandName()), e);
        }

        validateArgs(cmd.getArgs());
        return cmd;
    }
}