net.darkmist.alib.io.LineIterator.java Source code

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Here is the source code for net.darkmist.alib.io.LineIterator.java

Source

/*
 *  Copyright (C) 2012 Ed Schaller <schallee@darkmist.net>
 *
 *  This library 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 library 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 library; if not, write to the Free Software
 *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */

package net.darkmist.alib.io;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.util.Iterator;
import java.util.NoSuchElementException;

/** Wrapper around a stream to iterate through the stream one line at a time.
 * @deprecated Use {@link org.apache.commons.io.LineIterator} instead.
 */

@Deprecated
public class LineIterator implements Iterator<String> {
    private BufferedReader in;
    private String line;
    private IOException previousException;

    private void init(BufferedReader init_in) {
        this.in = init_in;
        line = null;
        previousException = null;
    }

    private void init(InputStream init_in) {
        init(new BufferedReader(new InputStreamReader(init_in)));
    }

    public LineIterator(InputStream in) {
        init(in);
    }

    public LineIterator(BufferedReader in) {
        init(in);
    }

    /** Get any {@link java.io.IOException IOException} caught but unreportable due to the
      * {@link java.util.Iterator Interator} interface. 
      * @return IOException Any previous caught  {@link java.io.IOException IOException} or null.
      */
    public IOException getIOException() {
        return previousException;
    }

    /** {@link java.util.Iterator#hasNext()} implementation.
      * @return True if more lines are availible, false if not.
      * As this can cause the underlying {@link java.io.InputStream InputStream} to throw
      * a {@link java.io.IOException IOException} but the {@link java.util.Iterator#hasNext()}
      * interface does not, false is returned instead of it being rethrown. The exception can be
      * retrieved via {@link #getIOException()}.
      */
    @Override
    public boolean hasNext() {
        if (previousException != null)
            return false;
        if (line != null)
            return true;
        try {
            line = in.readLine();
            if (line == null)
                return false;
            return true;
        } catch (IOException e) {
            previousException = e;
            return false;
        }
    }

    /** {@link java.util.Iterator#next()} implementation.
      * @return Next line of the source stream.
      * @throws NoSuchElementException in the case of a end of file or a {@link java.io.IOException}
      *    by the underlying {@link java.io.InputStream InputStream}. In the latter case the exception can
      *   be retrieved via {@link #getIOException()}.
      */
    @Override
    public String next() throws NoSuchElementException {
        String ret;

        if (previousException != null)
            throw new NoSuchElementException("Previous IOException reading from stream");
        if (line == null) {
            try {
                if ((line = in.readLine()) == null)
                    throw new NoSuchElementException("No more lines available");
            } catch (IOException e) {
                previousException = e;
                throw new NoSuchElementException("IOException reading next line.");
            }
        }
        ret = line;
        line = null;
        return ret;
    }

    /** Not supported.
      * @throws UnsupportedOperationException Always thrown.
      */
    @Override
    public void remove() throws UnsupportedOperationException {
        throw new UnsupportedOperationException("Remove is not supported");
    }
}