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The SoftiCAR Platform is a lightweight, Java-based library to create interactive business web applications.

There is a newer version: 50.0.0

package com.softicar.platform.common.io.resource.default_;

import com.softicar.platform.common.io.resource.key.IResourceKey;
import java.util.Objects;
import java.util.regex.Pattern;

/**
 * Facilitates handling and validation of a file name of a default resource, as
 * used in an {@link IResourceKey}.
 *
 * @author Alexander Schmidt
 */
public class DefaultResourceFilename {

	private static final Pattern VALIDATION_REGEX = Pattern.compile("[a-zA-Z0-9]((\\-)?[a-zA-Z0-9]+)*((\\.)?[a-zA-Z0-9]+)?");
	private final String filename;

	/**
	 * Constructs a new {@link DefaultResourceFilename} from the given literal
	 * default file name.
	 *
	 * @param filename
	 *            the default file name (never null)
	 * @throws NullPointerException
	 *             if the given {@link String} is null
	 */
	public DefaultResourceFilename(String filename) {

		this.filename = Objects.requireNonNull(filename);
	}

	@Override
	public String toString() {

		return filename;
	}

	/**
	 * Returns this {@link DefaultResourceFilename} as a {@link String}.
	 *
	 * @return this {@link DefaultResourceFilename} as a {@link String} (never
	 *         null)
	 */
	public String get() {

		return filename;
	}

	/**
	 * Checks whether the file name is valid for a default resource.
	 * 
	 * A file name is valid if all of the following conditions are met:
	 * 

	 * the {@link String} is non-empty
	 * all characters are either letters ("a-zA-Z"), or digits ("0-9"),
	 * dashes ("-") or dots (".")
	 * the first character is a letter or a digit
	 * the last character is a letter or a digit
	 * the {@link String} does not contain a dash or dot that is adjacent to
	 * another dash or dot
	 * the {@link String} contains at most one dot
	 * 
	 *
	 * @return true if the file name is valid; false otherwise
	 */
	public boolean isValid() {

		return VALIDATION_REGEX.asMatchPredicate().test(filename);
	}
}