Reader for the ISO-8859-1 encoding. : File Reader « File Input Output « Java






Reader for the ISO-8859-1 encoding.

  
/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 * 
 *      http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

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

/**
 * <p>
 * Reader for the ISO-8859-1 encoding.
 * </p>
 * 
 * @xerces.internal
 * 
 * @author Michael Glavassevich, IBM
 * 
 * @version $Id: Latin1Reader.java 446716 2006-09-15 20:28:48Z mrglavas $
 */
public class Latin1Reader extends Reader {

  //
  // Constants
  //

  /** Default byte buffer size (2048). */
  public static final int DEFAULT_BUFFER_SIZE = 2048;

  //
  // Data
  //

  /** Input stream. */
  protected final InputStream fInputStream;

  /** Byte buffer. */
  protected final byte[] fBuffer;

  //
  // Constructors
  //

  /**
   * Constructs an ISO-8859-1 reader from the specified input stream using the
   * default buffer size.
   * 
   * @param inputStream
   *          The input stream.
   */
  public Latin1Reader(InputStream inputStream) {
    this(inputStream, DEFAULT_BUFFER_SIZE);
  } // <init>(InputStream)

  /**
   * Constructs an ISO-8859-1 reader from the specified input stream and buffer
   * size.
   * 
   * @param inputStream
   *          The input stream.
   * @param size
   *          The initial buffer size.
   */
  public Latin1Reader(InputStream inputStream, int size) {
    this(inputStream, new byte[size]);
  } // <init>(InputStream, int)

  /**
   * Constructs an ISO-8859-1 reader from the specified input stream and buffer.
   * 
   * @param inputStream
   *          The input stream.
   * @param buffer
   *          The byte buffer.
   */
  public Latin1Reader(InputStream inputStream, byte[] buffer) {
    fInputStream = inputStream;
    fBuffer = buffer;
  } // <init>(InputStream, byte[])

  //
  // Reader methods
  //

  /**
   * Read a single character. This method will block until a character is
   * available, an I/O error occurs, or the end of the stream is reached.
   * 
   * <p>
   * Subclasses that intend to support efficient single-character input should
   * override this method.
   * 
   * @return The character read, as an integer in the range 0 to 255 (<tt>0x00-0xff</tt>),
   *         or -1 if the end of the stream has been reached
   * 
   * @exception IOException
   *              If an I/O error occurs
   */
  public int read() throws IOException {
    return fInputStream.read();
  } // read():int

  /**
   * Read characters into a portion of an array. This method will block until
   * some input is available, an I/O error occurs, or the end of the stream is
   * reached.
   * 
   * @param ch
   *          Destination buffer
   * @param offset
   *          Offset at which to start storing characters
   * @param length
   *          Maximum number of characters to read
   * 
   * @return The number of characters read, or -1 if the end of the stream has
   *         been reached
   * 
   * @exception IOException
   *              If an I/O error occurs
   */
  public int read(char ch[], int offset, int length) throws IOException {
    if (length > fBuffer.length) {
      length = fBuffer.length;
    }
    int count = fInputStream.read(fBuffer, 0, length);
    for (int i = 0; i < count; ++i) {
      ch[offset + i] = (char) (fBuffer[i] & 0xff);
    }
    return count;
  } // read(char[],int,int)

  /**
   * Skip characters. This method will block until some characters are
   * available, an I/O error occurs, or the end of the stream is reached.
   * 
   * @param n
   *          The number of characters to skip
   * 
   * @return The number of characters actually skipped
   * 
   * @exception IOException
   *              If an I/O error occurs
   */
  public long skip(long n) throws IOException {
    return fInputStream.skip(n);
  } // skip(long):long

  /**
   * Tell whether this stream is ready to be read.
   * 
   * @return True if the next read() is guaranteed not to block for input, false
   *         otherwise. Note that returning false does not guarantee that the
   *         next read will block.
   * 
   * @exception IOException
   *              If an I/O error occurs
   */
  public boolean ready() throws IOException {
    return false;
  } // ready()

  /**
   * Tell whether this stream supports the mark() operation.
   */
  public boolean markSupported() {
    return fInputStream.markSupported();
  } // markSupported()

  /**
   * Mark the present position in the stream. Subsequent calls to reset() will
   * attempt to reposition the stream to this point. Not all character-input
   * streams support the mark() operation.
   * 
   * @param readAheadLimit
   *          Limit on the number of characters that may be read while still
   *          preserving the mark. After reading this many characters,
   *          attempting to reset the stream may fail.
   * 
   * @exception IOException
   *              If the stream does not support mark(), or if some other I/O
   *              error occurs
   */
  public void mark(int readAheadLimit) throws IOException {
    fInputStream.mark(readAheadLimit);
  } // mark(int)

  /**
   * Reset the stream. If the stream has been marked, then attempt to reposition
   * it at the mark. If the stream has not been marked, then attempt to reset it
   * in some way appropriate to the particular stream, for example by
   * repositioning it to its starting point. Not all character-input streams
   * support the reset() operation, and some support reset() without supporting
   * mark().
   * 
   * @exception IOException
   *              If the stream has not been marked, or if the mark has been
   *              invalidated, or if the stream does not support reset(), or if
   *              some other I/O error occurs
   */
  public void reset() throws IOException {
    fInputStream.reset();
  } // reset()

  /**
   * Close the stream. Once a stream has been closed, further read(), ready(),
   * mark(), or reset() invocations will throw an IOException. Closing a
   * previously-closed stream, however, has no effect.
   * 
   * @exception IOException
   *              If an I/O error occurs
   */
  public void close() throws IOException {
    fInputStream.close();
  } // close()

} // class Latin1Reader

   
    
  








Related examples in the same category

1.Use a FileReader to display a text file.
2.Read the file one buffer at a time
3.Read file upside down
4.Loading text from a file
5.Reading Numbers from a Text File
6.Reading Numbers from a Text File, Line by Line
7.Indent - prepend leading spaces
8.Read a file and print, using BufferedReader and System.out
9.Open File By Name
10.Read a file containing an offset, and a String at that offset
11.Testing for end of file while reading a byte at a timeTesting for end of file while reading a byte at a time
12.File LockingFile Locking
13.Getting channels from streams
14.A word counting utility with FileReader.
15.Reads sequentially from multiple sources
16.Reader for UCS-2 and UCS-4 encodings. (i.e., encodings from ISO-10646-UCS-(2|4)).
17.This class is an part implementation of DataInput. It wraps a Reader object.
18.A StraightStreamReader is a bridge from byte streams to character streams
19.Read and return the entire contents of the supplied Reader. This method always closes the reader when finished reading.
20.Compare the contents of two Readers to determine if they are equal or not.
21.Read from Reader and write to Writer until there is no more input from reader.