用于判断字符结尾的输入流类

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

public class CharTerminatedInputStream extends InputStream {

  private InputStream in;

  private int match[];

  private int buffer[];

  private int pos = 0;

  private boolean endFound = false;

  public CharTerminatedInputStream(InputStream in, byte[] terminator) {
    if (terminator == null) {
      throw new IllegalArgumentException("The terminating character array cannot be null.");
    }
    if (terminator.length == 0) {
      throw new IllegalArgumentException("The terminating character array cannot be of zero length.");
    }
    match = new int[terminator.length];
    buffer = new int[terminator.length];
    for (int i = 0; i < terminator.length; i++) {
      match[i] = (int) terminator[i];
      buffer[i] = (int) terminator[i];
    }
    this.in = in;
  }

  public synchronized void reset() {
    endFound = false;
    pos = 0;
  }

  public int read() throws IOException {

    if (endFound) {
      return -1;
    }

    if (pos == 0) {
      int b = in.read();
      if (b == -1) {
        endFound = true;
        return -1;
      }
      if (b != match[0]) {
        return b;
      }
      buffer[0] = b;
      pos++;
    } else {
      if (buffer[0] != match[0]) {
        return topChar();
      }
    }
    for (int i = 0; i < match.length; i++) {
      if (i >= pos) {
        int b = in.read();
        if (b == -1) {
          return topChar();
        }
        buffer[pos] = b;
        pos++;
      }
      if (buffer[i] != match[i]) {
        return topChar();
      }
    }
    endFound = true;
    return -1;
  }

  private int topChar() {
    int b = buffer[0];
    if (pos > 1) {
      System.arraycopy(buffer, 1, buffer, 0, pos - 1);
    }
    pos--;
    return b;
  }
}