All Downloads are FREE. Search and download functionalities are using the official Maven repository.
  • Log In
  • Register

    • org.apache.commons.cli.PatternOptionBuilder Maven / Gradle / Ivy

    There is a newer version: 5.0.22
    Show newest version
    /**
 * 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.commons.cli;

import java.io.File;
import java.io.FileInputStream;
import java.net.URL;
import java.util.Date;

/**
 * 
    Allows Options to be created from a single String.
 * The pattern contains various single character flags and via
 * an optional punctuation character, their expected type.
 * 
    
 * 
 * 
 *   
 *   
 *   
 *   
 *   
 *   
 *   
 *   
 * 
    Overview of PatternOptionBuilder patterns
    a-a flag
    b@-b [classname]
    c>-c [filename]
    d+-d [classname] (creates object via empty constructor)
    e%-e [number] (creates Double/Long instance depending on existing of a '.')
    f/-f [url]
    g:-g [string]
    
 * 
 * 
    
 * For example, the following allows command line flags of '-v -p string-value -f /dir/file'.
 * The exclamation mark precede a mandatory option.
 * 
    
 *
 * 
     *     Options options = PatternOptionBuilder.parsePattern("vp:!f/");
 * 
    
 *
 * 
    
 * TODO: These need to break out to OptionType and also to be pluggable.
 * 
    
 *
 * @version $Id: PatternOptionBuilder.java 1677406 2015-05-03 14:27:31Z britter $
 */
public class PatternOptionBuilder
{
    /** String class */
    public static final Class STRING_VALUE = String.class;

    /** Object class */
    public static final Class OBJECT_VALUE = Object.class;

    /** Number class */
    public static final Class NUMBER_VALUE = Number.class;

    /** Date class */
    public static final Class DATE_VALUE = Date.class;

    /** Class class */
    public static final Class CLASS_VALUE = Class.class;

    /// can we do this one??
    // is meant to check that the file exists, else it errors.
    // ie) it's for reading not writing.

    /** FileInputStream class */
    public static final Class EXISTING_FILE_VALUE = FileInputStream.class;

    /** File class */
    public static final Class FILE_VALUE = File.class;

    /** File array class */
    public static final Class FILES_VALUE = File[].class;

    /** URL class */
    public static final Class URL_VALUE = URL.class;

    /**
     * Retrieve the class that ch represents.
     *
     * @param ch the specified character
     * @return The class that ch represents
     */
    public static Object getValueClass(char ch)
    {
        switch (ch)
        {
            case '@':
                return PatternOptionBuilder.OBJECT_VALUE;
            case ':':
                return PatternOptionBuilder.STRING_VALUE;
            case '%':
                return PatternOptionBuilder.NUMBER_VALUE;
            case '+':
                return PatternOptionBuilder.CLASS_VALUE;
            case '#':
                return PatternOptionBuilder.DATE_VALUE;
            case '<':
                return PatternOptionBuilder.EXISTING_FILE_VALUE;
            case '>':
                return PatternOptionBuilder.FILE_VALUE;
            case '*':
                return PatternOptionBuilder.FILES_VALUE;
            case '/':
                return PatternOptionBuilder.URL_VALUE;
        }

        return null;
    }

    /**
     * Returns whether ch is a value code, i.e.
     * whether it represents a class in a pattern.
     *
     * @param ch the specified character
     * @return true if ch is a value code, otherwise false.
     */
    public static boolean isValueCode(char ch)
    {
        return ch == '@'
                || ch == ':'
                || ch == '%'
                || ch == '+'
                || ch == '#'
                || ch == '<'
                || ch == '>'
                || ch == '*'
                || ch == '/'
                || ch == '!';
    }

    /**
     * Returns the {@link Options} instance represented by pattern.
     *
     * @param pattern the pattern string
     * @return The {@link Options} instance
     */
    public static Options parsePattern(String pattern)
    {
        char opt = ' ';
        boolean required = false;
        Class type = null;

        Options options = new Options();

        for (int i = 0; i < pattern.length(); i++)
        {
            char ch = pattern.charAt(i);

            // a value code comes after an option and specifies
            // details about it
            if (!isValueCode(ch))
            {
                if (opt != ' ')
                {
                    final Option option = Option.builder(String.valueOf(opt))
                        .hasArg(type != null)
                        .required(required)
                        .type(type)
                        .build();
                    
                    // we have a previous one to deal with
                    options.addOption(option);
                    required = false;
                    type = null;
                    opt = ' ';
                }

                opt = ch;
            }
            else if (ch == '!')
            {
                required = true;
            }
            else
            {
                type = (Class) getValueClass(ch);
            }
        }

        if (opt != ' ')
        {
            final Option option = Option.builder(String.valueOf(opt))
                .hasArg(type != null)
                .required(required)
                .type(type)
                .build();
            
            // we have a final one to deal with
            options.addOption(option);
        }

        return options;
    }
}
    
    
    
    

    




    
    
    © 2015 - 2024 Weber Informatics LLC | Privacy Policy