pop3inputstream.java~1~

来自「实例大全」· JAVA~1~ 代码 · 共 121 行

package injektilo.net;

import java.io.*;

/**
 * Utility class used to retrieve messages using the Pop3Connection
 * class.
 *
 * <p>Copyright (c) 1998 Jason Diamond</p>
 *
 * <p>[e-mail]<br>
 * http://www.geocities.com/ResearchTriangle/Thinktank/8343/</p>
 *
 * @author Jason Diamond
 * @version 1.1.1
 *
 * History:
 *
 * 4-Nov-1998 v1.1.1
 *  initial release
 *
 */

public class Pop3InputStream
    extends FilterInputStream
{
  public Pop3InputStream(InputStream is) {
    super(is);
  }
  
  private static final int CR = 13;
  private static final int LF = 10;
  private static final int DOT = 46;
  
  private boolean eof;
    
  private boolean gotCR;
  private boolean gotLF;  
  
  public int read()
      throws IOException
  {
    if (eof) {
      return -1;
    }
    
    int c = in.read();
    
    if (c == CR) {
      gotCR = true;;
      return c;
    }
    
    if (gotCR & c == LF) {
      gotLF = true;
      return c;
    }
    
//    if (c == LF) {
//      gotLF = true;
//      return c;
//    }
    
    if (gotLF) {
      if (c == DOT) {
        c = in.read();
        if (c == CR) {
          c = in.read();
          if (c == LF) {
            eof = true;
            return -1;
          }
        }
      }
      gotCR = false;
      gotLF = false;
    }
    
    return c;
  }
  
  /* The default FilterInputStream calls in.read(byte[], int, int)
   * which calls whatever read() method in implements.
   * Therefore, we have to override that with basically the same
   * code but make sure it calls the read() method defined above.
   */
  
  public int read(byte[] buf, int off, int len)
    throws IOException
  {
    if (len <= 0) {
      return 0;
    }
    
    int c = read();
    
    if (c == -1) {
      return -1;
    }  
    
    buf[off] = (byte) c;
    
    int i = 1;
    
    try {
      for (; i < len ; ++i) {
        c = read();
    
        if (c == -1) {
          break;
        }
    
        if (buf != null) {
          buf[off + i] = (byte) c;
        }
      }
    } catch (IOException e) {}
    
    return i;
  }  
}