hadoop CommandFormat 源码

haddop CommandFormat 代码

文件路径：/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/fs/shell/CommandFormat.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.hadoop.fs.shell;

import java.util.ArrayList;
import java.util.Arrays;
import java.util.HashMap;
import java.util.HashSet;
import java.util.List;
import java.util.Map;
import java.util.Set;

/**
 * Parse the args of a command and check the format of args.
 */
public class CommandFormat {
  final int minPar, maxPar;
  final Map<String, Boolean> options = new HashMap<String, Boolean>();
  final Map<String, String> optionsWithValue = new HashMap<String, String>();
  boolean ignoreUnknownOpts = false;
  
  /**
   * @deprecated use replacement since name is an unused parameter
   * @param name of command, but never used
   * @param min see replacement
   * @param max see replacement
   * @param possibleOpt see replacement
   * @see #CommandFormat(int, int, String...)
   */
  @Deprecated
  public CommandFormat(String name, int min, int max, String ... possibleOpt) {
    this(min, max, possibleOpt);
  }
  
  /**
   * Simple parsing of command line arguments
   * @param min minimum arguments required
   * @param max maximum arguments permitted
   * @param possibleOpt list of the allowed switches
   */
  public CommandFormat(int min, int max, String ... possibleOpt) {
    minPar = min;
    maxPar = max;
    for (String opt : possibleOpt) {
      if (opt == null) {
        ignoreUnknownOpts = true;
      } else {
        options.put(opt, Boolean.FALSE);
      }
    }
  }

  /**
   * add option with value
   *
   * @param option option name
   */
  public void addOptionWithValue(String option) {
    if (options.containsKey(option)) {
      throw new DuplicatedOptionException(option);
    }
    optionsWithValue.put(option, null);
  }

  /** Parse parameters starting from the given position
   * Consider using the variant that directly takes a List
   * 
   * @param args an array of input arguments
   * @param pos the position at which starts to parse
   * @return a list of parameters
   */
  public List<String> parse(String[] args, int pos) {
    List<String> parameters = new ArrayList<String>(Arrays.asList(args));
    parameters.subList(0, pos).clear();
    parse(parameters);
    return parameters;
  }

  /** Parse parameters from the given list of args.  The list is
   *  destructively modified to remove the options.
   * 
   * @param args as a list of input arguments
   */
  public void parse(List<String> args) {
    int pos = 0;
    while (pos < args.size()) {
      String arg = args.get(pos);
      // stop if not an opt, or the stdin arg "-" is found
      if (!arg.startsWith("-") || arg.equals("-")) { 
        break;
      } else if (arg.equals("--")) { // force end of option processing
        args.remove(pos);
        break;
      }
      
      String opt = arg.substring(1);
      if (options.containsKey(opt)) {
        args.remove(pos);
        options.put(opt, Boolean.TRUE);
      } else if (optionsWithValue.containsKey(opt)) {
        args.remove(pos);
        if (pos < args.size() && (args.size() > minPar)
                && !args.get(pos).startsWith("-")) {
          arg = args.get(pos);
          args.remove(pos);
        } else {
          arg = "";
        }
        if (!arg.startsWith("-") || arg.equals("-")) {
          optionsWithValue.put(opt, arg);
        }
      } else if (ignoreUnknownOpts) {
        pos++;
      } else {
        throw new UnknownOptionException(arg);
      }
    }
    int psize = args.size();
    if (psize < minPar) {
      throw new NotEnoughArgumentsException(minPar, psize);
    }
    if (psize > maxPar) {
      throw new TooManyArgumentsException(maxPar, psize);
    }
  }
  
  /** Return if the option is set or not
   * 
   * @param option String representation of an option
   * @return true is the option is set; false otherwise
   */
  public boolean getOpt(String option) {
    return options.containsKey(option) ? options.get(option) : false;
  }

  /**
   * get the option's value
   *
   * @param option option name
   * @return option value
   * if option exists, but no value assigned, return ""
   * if option not exists, return null
   */
  public String getOptValue(String option) {
    return optionsWithValue.get(option);
  }

  /** Returns all the options that are set
   * 
   * @return Set{@literal <}String{@literal >} of the enabled options
   */
  public Set<String> getOpts() {
    Set<String> optSet = new HashSet<>();
    for (Map.Entry<String, Boolean> entry : options.entrySet()) {
      if (entry.getValue()) {
        optSet.add(entry.getKey());
      }
    }
    return optSet;
  }
  
  /** Used when the arguments exceed their bounds 
   */
  public static abstract class IllegalNumberOfArgumentsException
  extends IllegalArgumentException {
    private static final long serialVersionUID = 0L;
    protected int expected;
    protected int actual;

    protected IllegalNumberOfArgumentsException(int want, int got) {
      expected = want;
      actual = got;
    }

    @Override
    public String getMessage() {
      return "expected " + expected + " but got " + actual;
    }
  }

  /** Used when too many arguments are supplied to a command
   */
  public static class TooManyArgumentsException
  extends IllegalNumberOfArgumentsException {
    private static final long serialVersionUID = 0L;

    public TooManyArgumentsException(int expected, int actual) {
      super(expected, actual);
    }

    @Override
    public String getMessage() {
      return "Too many arguments: " + super.getMessage();
    }
  }
  
  /** Used when too few arguments are supplied to a command
   */
  public static class NotEnoughArgumentsException
  extends IllegalNumberOfArgumentsException {
    private static final long serialVersionUID = 0L;

    public NotEnoughArgumentsException(int expected, int actual) {
      super(expected, actual);
    }

    @Override
    public String getMessage() {
      return "Not enough arguments: " + super.getMessage();
    }
  }
  
  /** Used when an unsupported option is supplied to a command
   */
  public static class UnknownOptionException extends IllegalArgumentException {
    private static final long serialVersionUID = 0L;
    protected String option = null;
    
    public UnknownOptionException(String unknownOption) {
      super("Illegal option " + unknownOption);
      option = unknownOption;
    }
    
    public String getOption() {
      return option;
    }
  }

  /**
   * Used when a duplicated option is supplied to a command.
   */
  public static class DuplicatedOptionException extends IllegalArgumentException {
    private static final long serialVersionUID = 0L;

    public DuplicatedOptionException(String duplicatedOption) {
      super("option " + duplicatedOption + " already exists!");
    }
  }
}

相关信息

hadoop 源码目录

相关文章

hadoop AclCommands 源码

hadoop Command 源码

hadoop CommandFactory 源码

hadoop CommandUtils 源码

hadoop CommandWithDestination 源码

hadoop Concat 源码

hadoop CopyCommandWithMultiThread 源码

hadoop CopyCommands 源码

hadoop Count 源码

hadoop Delete 源码