extends FilterWriter and extends FilterReader : FileWriter « File Input Output « Java





extends FilterWriter and extends FilterReader

/*
 * Copyright (c) 1995 - 2008 Sun Microsystems, Inc.  All rights reserved.
 *
 * 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 Sun Microsystems 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.
 */

import java.io.FileReader;
import java.io.FileWriter;
import java.io.FilterReader;
import java.io.FilterWriter;
import java.io.IOException;
import java.io.Reader;
import java.io.Writer;

public class CounterDemo {
  public static void main(String[] args) throws IOException {
    CountReader cr = new CountReader(new FileReader("xanadu.txt"), 'e');
    CountWriter cw = new CountWriter(new FileWriter("outagain.txt"), 'e');
    int c = 0;
    while ((c = cr.read()) != -1) {
      cw.write(c);
    }
    System.out.println(cr.getCount());
    System.out.println(cw.getCount());
    cr.close();
    cw.close();
  }
}

/*
 * Copyright (c) 1995 - 2008 Sun Microsystems, Inc. All rights reserved.
 * 
 * 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 Sun Microsystems 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.
 */

class CountWriter extends FilterWriter {

  private int count = 0;
  private char lookFor = 0;

  public CountWriter(Writer in, char lookFor) {
    super(in);
    this.lookFor = lookFor;
  }

  public void write(int character) throws IOException {
    super.write(character);
    if ((char) character == lookFor) {
      count++;
    }
  }

  public void write(char[] cbuf) throws IOException {
    super.write(cbuf);
    int length = cbuf.length;
    for (int i = 0; i < length; i++) {
      if (cbuf[i] == lookFor) {
        count++;
      }
    }
  }

  public void write(char[] cbuf, int off, int len) throws IOException {
    super.write(cbuf, off, len);
    int length = cbuf.length;
    for (int i = 0; i < length; i++) {
      if (cbuf[i] == lookFor) {
        count++;
      }
    }
  }

  public void write(String str) throws IOException {
    super.write(str);
    int length = str.length();
    for (int i = 0; i < length; i++) {
      if (str.charAt(i) == lookFor) {
        count++;
      }
    }
  }

  public void write(String str, int off, int len) throws IOException {
    super.write(str, off, len);
    int length = str.length();
    for (int i = 0; i < length; i++) {
      if (str.charAt(i) == lookFor) {
        count++;
      }
    }
  }

  public int getCount() {
    return count;
  }
}

/*
 * Copyright (c) 1995 - 2008 Sun Microsystems, Inc. All rights reserved.
 * 
 * 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 Sun Microsystems 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.
 */
class CountReader extends FilterReader {

  private int count = 0;
  private char lookFor = 0;

  public CountReader(Reader in, char lookFor) {
    super(in);
    this.lookFor = lookFor;
  }

  public int read() throws IOException {
    int character = super.read();
    if ((char) character == lookFor) {
      count++;
    }
    return character;
  }

  public int read(char[] cbuf) throws IOException {
    int numChars = super.read(cbuf);
    int length = cbuf.length;
    for (int i = 0; i < length; i++) {
      if (cbuf[i] == lookFor) {
        count++;
      }
    }
    return numChars;
  }

  public int read(char[] cbuf, int off, int len) throws IOException {
    int numChars = super.read(cbuf, off, len);
    int length = cbuf.length;
    for (int i = 0; i < length; i++) {
      if (cbuf[i] == lookFor) {
        count++;
      }
    }
    return numChars;
  }

  public void reset() throws IOException {
    super.reset();
    count = 0;
  }

  public boolean markSupported() {
    return false;
  }

  public void mark(int readAheadLimit) throws IOException {
    throw new IOException("CountReader does not support the mark() operation.");
  }

  public int getCount() {
    return count;
  }
}

 










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