de.intarsys.tools.reader.FillReader Maven / Gradle / Ivy

Go to download
Show more of this group Show more artifacts with this name
Show all versions of isrt Show documentation
The basic runtime tools and interfaces for intarsys components.
There is a newer version: 4.11
/*
 * Copyright (c) 2007, intarsys consulting GmbH
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 * - Redistributions of source code must retain the above copyright notice,
 *   this list of conditions and the following disclaimer.
 *
 * - Redistributions in binary form must reproduce the above copyright notice,
 *   this list of conditions and the following disclaimer in the documentation
 *   and/or other materials provided with the distribution.
 *
 * - Neither the name of intarsys nor the names of its contributors may be used
 *   to endorse or promote products derived from this software without specific
 *   prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 */
package de.intarsys.tools.reader;

import java.io.IOException;
import java.io.Reader;

/**
 * A Helper reader that repeatedly returns the characters in a predefined
 * pattern until it is closed.
 * 
 */
public class FillReader extends Reader {
	/**
	 * the pattern that is "read" all over.
	 */
	private String pattern;

	/**
	 * Flag if reader is closed.
	 */
	private boolean closed = false;

	/**
	 * The position within the string
	 */
	private int pos = 0;

	/**
	 * Create a FillReader on string.
	 * 
	 * @param pattern
	 *            The string that is read all over again.
	 */
	public FillReader(String pattern) {
		super();
		if (pattern == null) {
			throw new NullPointerException("pattern may not be null");
		}
		this.pattern = pattern;
	}

	/*
	 * (non-Javadoc)
	 * 
	 * @see java.io.Reader#close()
	 */
	public void close() throws IOException {
		closed = true;
	}

	/*
	 * (non-Javadoc)
	 * 
	 * @see java.io.Reader#read(char[], int, int)
	 */
	public int read(char[] cbuf, int off, int len) throws IOException {
		for (int i = off; i < (off + len); i++) {
			int c = read();
			if (c == -1) {
				return off - i;
			} else {
				cbuf[i] = (char) c;
			}
		}
		return len;
	}

	/*
	 * (non-Javadoc)
	 * 
	 * @see java.io.Reader#read()
	 */
	public int read() throws IOException {
		if (closed) {
			return -1;
		} else {
			if (pos >= pattern.length()) {
				if (pattern.length() == 0) {
					return -1;
				}
				pos = 0;
			}
			return pattern.charAt(pos++);
		}
	}
}