jp.go.nict.langrid.commons.lang.CharSequenceUtil Maven / Gradle / Ivy

Go to download

Show more of this group Show more artifacts with this name
Show all versions of jp.go.nict.langrid.commons Show documentation

Common and utility library for the Service Grid Server Software and java web services.

The newest version!

/*
 * $Id: CharacterUtil.java 182 2010-10-02 03:16:36Z t-nakaguchi $
 *
 * This is a program for Language Grid Core Node. This combines multiple language resources and provides composite language services.
 * Copyright (C) 2013 NICT Language Grid Project.
 *
 * This program is free software: you can redistribute it and/or modify it 
 * under the terms of the GNU Lesser General Public License as published by 
 * the Free Software Foundation, either version 2.1 of the License, or (at 
 * your option) any later version.
 *
 * This program is distributed in the hope that it will be useful, but 
 * WITHOUT ANY WARRANTY; without even the implied warranty of 
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser 
 * General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License 
 * along with this program. If not, see .
 */
package jp.go.nict.langrid.commons.lang;

/**
 * @author Takao Nakaguchi
 */
public class CharSequenceUtil {
	public static CharSequence empty(){
		return new CharSequence() {
			@Override
			public CharSequence subSequence(int start, int end) {
				checkIndex(start, end, length());
				return empty();
			}

			@Override
			public int length() {
				return 0;
			}

			@Override
			public char charAt(int index) {
				throw new IndexOutOfBoundsException();
			}

			@Override
			public String toString() {
				return new StringBuilder().append(this).toString();
			}
		};
	}

	public static CharSequence repeat(final char c, final int count){
		return new CharSequence() {
			@Override
			public CharSequence subSequence(int start, int end) {
				checkIndex(start, end, length());
				return repeat(c, end - start);
			}

			@Override
			public int length() {
				return count;
			}

			@Override
			public char charAt(int arg0) {
				return c;
			}

			@Override
			public String toString() {
				return new StringBuilder().append(this).toString();
			}
		};
	}

	private static void checkIndex(int start, int end, int length){
		if(start < 0) throw new IndexOutOfBoundsException();
		if(end < 0) throw new IndexOutOfBoundsException();
		if(end > length) throw new IndexOutOfBoundsException();
		if(start > end) throw new IndexOutOfBoundsException();
	}
}