Java/File Input Output/PipedReader

Материал из Java эксперт
Перейти к: навигация, поиск

Create PipedReader out of PipedWriter

/*
 * 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.BufferedReader;
import java.io.FileReader;
import java.io.IOException;
import java.io.PipedReader;
import java.io.PipedWriter;
import java.io.PrintWriter;
import java.io.Reader;
public class RhymingWords {
  public static void main(String[] args) throws IOException {
    FileReader words = new FileReader("words.txt");
    // do the reversing and sorting
    Reader rhymedWords = reverse(sort(reverse(words)));
    // write new list to standard out
    BufferedReader in = new BufferedReader(rhymedWords);
    String input;
    while ((input = in.readLine()) != null)
      System.out.println(input);
    in.close();
  }
  public static Reader reverse(Reader source) throws IOException {
    BufferedReader in = new BufferedReader(source);
    PipedWriter pipeOut = new PipedWriter();
    PipedReader pipeIn = new PipedReader(pipeOut);
    PrintWriter out = new PrintWriter(pipeOut);
    new ReverseThread(out, in).start();
    return pipeIn;
  }
  public static Reader sort(Reader source) throws IOException {
    BufferedReader in = new BufferedReader(source);
    PipedWriter pipeOut = new PipedWriter();
    PipedReader pipeIn = new PipedReader(pipeOut);
    PrintWriter out = new PrintWriter(pipeOut);
    new SortThread(out, in).start();
    return pipeIn;
  }
}
/*
 * 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 SortThread extends Thread {
  private PrintWriter out = null;
  private BufferedReader in = null;
  public SortThread(PrintWriter out, BufferedReader in) {
    this.out = out;
    this.in = in;
  }
  public void run() {
    int MAXWORDS = 50;
    if (out != null && in != null) {
      try {
        String[] listOfWords = new String[MAXWORDS];
        int numwords = 0;
        while ((listOfWords[numwords] = in.readLine()) != null)
          numwords++;
        quicksort(listOfWords, 0, numwords - 1);
        for (int i = 0; i < numwords; i++)
          out.println(listOfWords[i]);
        out.close();
      } catch (IOException e) {
        System.err.println("SortThread run: " + e);
      }
    }
  }
  private static void quicksort(String[] a, int lo0, int hi0) {
    int lo = lo0;
    int hi = hi0;
    if (lo >= hi)
      return;
    String mid = a[(lo + hi) / 2];
    while (lo < hi) {
      while (lo < hi && a[lo].rupareTo(mid) < 0)
        lo++;
      while (lo < hi && a[hi].rupareTo(mid) > 0)
        hi--;
      if (lo < hi) {
        String T = a[lo];
        a[lo] = a[hi];
        a[hi] = T;
        lo++;
        hi--;
      }
    }
    if (hi < lo) {
      int T = hi;
      hi = lo;
      lo = T;
    }
    quicksort(a, lo0, lo);
    quicksort(a, lo == lo0 ? lo + 1 : lo, hi0);
  }
}
/*
 * 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 ReverseThread extends Thread {
  private PrintWriter out = null;
  private BufferedReader in = null;
  public ReverseThread(PrintWriter out, BufferedReader in) {
    this.out = out;
    this.in = in;
  }
  public void run() {
    if (out != null && in != null) {
      try {
        String input;
        while ((input = in.readLine()) != null) {
          out.println(reverseIt(input));
          out.flush();
        }
        out.close();
      } catch (IOException e) {
        System.err.println("ReverseThread run: " + e);
      }
    }
  }
  private String reverseIt(String source) {
    int i, len = source.length();
    StringBuffer dest = new StringBuffer(len);
    for (i = (len - 1); i >= 0; i--)
      dest.append(source.charAt(i));
    return dest.toString();
  }
}