WritableLineReader.java

/*
    GNU GENERAL LICENSE
    Copyright (C) 2006 The Lobo Project. Copyright (C) 2014 - 2017 Lobo Evolution

    This program is free software; you can redistribute it and/or
    modify it under the terms of the GNU General Public
    License as published by the Free Software Foundation; either
    verion 3 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
    General License for more details.

    You should have received a copy of the GNU General Public
    along with this program.  If not, see <http://www.gnu.org/licenses/>.
    

    Contact info: lobochief@users.sourceforge.net; ivan.difrancesco@yahoo.it
 */
/*
 * Created on Nov 13, 2005
 */
package org.lobobrowser.html.io;

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

/**
 * The Class WritableLineReader.
 */
public class WritableLineReader extends LineNumberReader {

    /**
     * Instantiates a new writable line reader.
     *
     * @param reader
     *            the reader
     * @param bufferSize
     *            the buffer size
     */
    public WritableLineReader(Reader reader, int bufferSize) {
        super(reader, bufferSize);
    }

    /**
     * Instantiates a new writable line reader.
     *
     * @param reader
     *            the reader
     */
    public WritableLineReader(Reader reader) {
        super(reader);
    }

    /*
     * Note: Not implicitly thread safe.
     */
    /*
     * (non-Javadoc)
     * @see java.io.LineNumberReader#read()
     */
    @Override
    public int read() throws IOException {
        StringBuffer sb = this.writeBuffer;
        if ((sb != null) && (sb.length() > 0)) {
            char ch = sb.charAt(0);
            sb.deleteCharAt(0);
            if (sb.length() == 0) {
                this.writeBuffer = null;
            }
            return ch;
        }
        return super.read();
    }

    /*
     * (non-Javadoc) Note: Not implicitly thread safe.
     * @see java.io.Reader#read(byte[], int, int)
     */
    @Override
    public int read(char[] b, int off, int len) throws IOException {
        StringBuffer sb = this.writeBuffer;
        if ((sb != null) && (sb.length() > 0)) {
            int srcEnd = Math.min(sb.length(), len);
            sb.getChars(0, srcEnd, b, off);
            sb.delete(0, srcEnd);
            if (sb.length() == 0) {
                this.writeBuffer = null;
            }
            return srcEnd;
        }
        return super.read(b, off, len);
    }

    /*
     * (non-Javadoc)
     * @see java.io.BufferedReader#ready()
     */
    @Override
    public boolean ready() throws IOException {
        StringBuffer sb = this.writeBuffer;
        if ((sb != null) && (sb.length() > 0)) {
            return true;
        }
        return super.ready();
    }

    /*
     * (non-Javadoc) Note: Not implicitly thread safe.
     * @see java.io.Reader#close()
     */
    @Override
    public void close() throws IOException {
        this.writeBuffer = null;
        super.close();
    }

    /** The write buffer. */
    private StringBuffer writeBuffer = null;

    /**
     * Note: Not implicitly thread safe.
     *
     * @param text
     *            the text
     * @throws IOException
     *             Signals that an I/O exception has occurred.
     */
    public void write(String text) throws IOException {
        // Document overrides this to know that new data is coming.
        StringBuffer sb = this.writeBuffer;
        if (sb == null) {
            sb = new StringBuffer();
            this.writeBuffer = sb;
        }
        sb.append(text);
    }
}