A representation of the command line arguments passed to a Java class' main(String[]) method : Console « Development Class « Java
A representation of the command line arguments passed to a Java class' main(String[]) method
/*
* 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.
*
*/
import java.util.ArrayList;
import java.util.HashMap;
import java.util.HashSet;
import java.util.List;
import java.util.Map;
import java.util.Set;
/**
*
* CommandLine is a representation of the command line arguments passed to
* a Java class' main(String[]) method. It parses the arguments for flags
* (tokens prefixed with a dash ('-')), flag-value pairs, and an ordered
* list of argument values.
*
* @author Dan Jemiolo (danj)
*
*/
public class CommandLine
{
//
// all non-flag values
//
private String[] _arguments = null;
//
// the flags (-foo) that were found on the command line
//
private Map _flags = new HashMap();
//
// the flag values that are expected to be followed with a value
// that allows the application to process the flag.
//
private Set _flagsWithValues = new HashSet();
/**
*
* @return All of the values specified on the command line that were
* not a flag or associated with a flag.
*
*/
public String[] getArguments()
{
return _arguments;
}
/**
*
* @param flagName
*
* @return The value that was specified after the flag, or null if
* the flag was not specified.
*
* @see #hasFlag(String)
*
*/
public String getFlagValue(String flagName)
{
return (String)_flags.get(flagName);
}
public int getNumberOfArguments()
{
return _arguments.length;
}
public int getNumberOfFlags()
{
return _flags.size();
}
/**
*
* @param flagName
*
* @return True if the flag was specified on the command line.
*
*/
public boolean hasFlag(String flagName)
{
return _flags.containsKey(flagName);
}
/**
*
* Reads through each argument in the given array, picking out the
* flags (and optionally,their values) from the regular arguments.
* Users should use the saveFlagValue(String) method before this one
* in order to have their command line parsed correctly.
*
* @param args
* The command line arguments given to the application.
*
*/
public void parse(String[] args)
{
List regularArgs = new ArrayList();
for (int n = 0; n < args.length; ++n)
{
if (args[n].charAt(0) == '-')
{
String name = args[n];
String value = null;
if (_flagsWithValues.contains(args[n]) &&
n < args.length - 1)
value = args[++n];
_flags.put(name, value);
}
else
regularArgs.add(args[n]);
}
int size = regularArgs.size();
_arguments = (String[])regularArgs.toArray(new String[size]);
}
/**
*
* Tells the command line parser to associate the given flag with the
* value that comes after it in the list of arguments (if the flag is
* found). This will allow the user to retrieve the flag-value pair
* later and prevent the flag value from being lumped in with the
* regular arguments.
*
* @param flagName
*
*/
public void saveFlagValue(String flagName)
{
_flagsWithValues.add(flagName);
}
}
