alluxio.shell.command.AbstractShellCommand.java Source code

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Here is the source code for alluxio.shell.command.AbstractShellCommand.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.shell.command;

import alluxio.client.file.FileSystem;

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

import javax.annotation.concurrent.ThreadSafe;

/**
 * The base class for all the {@link ShellCommand} classes. It provides a default argument
 * validation method and a place to hold the {@link FileSystem} client.
 */
@ThreadSafe
public abstract class AbstractShellCommand implements ShellCommand {

    protected FileSystem mFileSystem;
    protected static final Option RECURSIVE_OPTION = Option.builder("R").required(false).hasArg(false)
            .desc("recursive").build();
    protected static final Option READONLY_OPTION = Option.builder("readonly").required(false).hasArg(false)
            .desc("readonly").build();
    protected static final Option MOUNT_SHARED_OPTION = Option.builder("shared").required(false).hasArg(false)
            .desc("shared").build();

    // TODO(gpang): Investigate property=value style of cmdline options. They didn't seem to
    // support spaces in values.
    protected static final Option PROPERTY_FILE_OPTION = Option.builder("P").required(false).numberOfArgs(1)
            .desc("properties file name").build();
    protected static final Option FORCE_OPTION = Option.builder("f").required(false).hasArg(false).desc("force")
            .build();
    protected static final Option LIST_DIR_AS_FILE_OPTION = Option.builder("d").required(false).hasArg(false)
            .desc("list directories as plain files").build();
    protected static final Option LIST_PINNED_FILES_OPTION = Option.builder("p").required(false).hasArg(false)
            .desc("list all pinned files").build();
    protected static final Option FIX_INCONSISTENT_FILES = Option.builder("r").required(false).hasArg(false)
            .desc("repair inconsistent files").build();
    protected static final Option LIST_HUMAN_READABLE_OPTION = Option.builder("h").required(false).hasArg(false)
            .desc("print human-readable format sizes").build();

    protected AbstractShellCommand(FileSystem fs) {
        mFileSystem = fs;
    }

    /**
     * Checks if the arguments are valid.
     *
     * @param args the arguments for the command, excluding the command name and options
     * @return whether the args are valid
     */
    protected boolean validateArgs(String... args) {
        boolean valid = args.length == getNumOfArgs();
        if (!valid) {
            System.out.println(
                    getCommandName() + " takes " + getNumOfArgs() + " arguments, " + " not " + args.length + "\n");
        }
        return valid;
    }

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

    /**
     * Gets the supported Options of the command.
     *
     * @return the Options
     */
    protected Options getOptions() {
        return new Options();
    }

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

        try {
            cmd = parser.parse(opts, args, true /* stopAtNonOption */);
        } catch (ParseException e) {
            // TODO(ifcharming): improve the error message when an unregistered option appears
            System.err.println("Unable to parse input args: " + e.getMessage());
            return null;
        }

        if (!validateArgs(cmd.getArgs())) {
            return null;
        }
        return cmd;
    }
}