adding a FileValidator results in ClassCastException in parser.parseAndHelp(args)

When I add a FileValidator.getExistingFileInstance() to an Argument, I get a ClassCastException when I parse args.

Below is a testcase invoke with

java org.apache.commons.cli2.issues.CLI2Sample -classpath commons-cli-2.0-SNAPSHOT.jar --file-name path-to-an-existing-file

Run it and you get:

Exception in thread "main" java.lang.ClassCastException: java.io.File cannot be cast to java.lang.String
at org.apache.commons.cli2.validation.FileValidator.validate(FileValidator.java:122)
at org.apache.commons.cli2.option.ArgumentImpl.validate(ArgumentImpl.java:250)
at org.apache.commons.cli2.option.ParentImpl.validate(ParentImpl.java:123)
at org.apache.commons.cli2.option.DefaultOption.validate(DefaultOption.java:175)
at org.apache.commons.cli2.option.GroupImpl.validate(GroupImpl.java:264)
at org.apache.commons.cli2.commandline.Parser.parse(Parser.java:105)
at org.apache.commons.cli2.commandline.Parser.parseAndHelp(Parser.java:125)
at org.apache.commons.cli2.issues.CLI2Sample.main(CLI2Sample.java:38)

Comment out the withValidator call and it runs with no exception.

I also get a similar ClassCastException if I add a

.withValidator(NumberValidator.getIntegerInstance())

to another option/argument.

Here is the source

package org.apache.commons.cli2.issues;

import java.io.File;
import org.apache.commons.cli2.CommandLine;
import org.apache.commons.cli2.Group;
import org.apache.commons.cli2.builder.ArgumentBuilder;
import org.apache.commons.cli2.builder.DefaultOptionBuilder;
import org.apache.commons.cli2.builder.GroupBuilder;
import org.apache.commons.cli2.commandline.Parser;
import org.apache.commons.cli2.option.DefaultOption;
import org.apache.commons.cli2.validation.FileValidator;

public class CLI2Sample
{
public static void main(String[] args)

{ final DefaultOptionBuilder obuilder = new DefaultOptionBuilder(); final ArgumentBuilder abuilder = new ArgumentBuilder(); final GroupBuilder gbuilder = new GroupBuilder(); DefaultOption fileNameOption = obuilder .withShortName("f") .withLongName("file-name") .withRequired(true) .withDescription("name of an existing file") .withArgument(abuilder .withName("file-name") .withValidator(FileValidator.getExistingFileInstance()) .create()) .create(); Group options = gbuilder .withName("options") .withOption(fileNameOption) .create(); Parser parser = new Parser(); parser.setHelpTrigger("--help"); parser.setGroup(options); CommandLine cl = parser.parseAndHelp(args); }

}