CheckedOutputStream.java 3.1 KB

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  1. /* CheckedOutputStream.java - Compute checksum of data being written.
  2. Copyright (C) 1999, 2000 Free Software Foundation, Inc.
  3. This file is part of GNU Classpath.
  4. GNU Classpath is free software; you can redistribute it and/or modify
  5. it under the terms of the GNU General Public License as published by
  6. the Free Software Foundation; either version 2, or (at your option)
  7. any later version.
  8. GNU Classpath is distributed in the hope that it will be useful, but
  9. WITHOUT ANY WARRANTY; without even the implied warranty of
  10. MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  11. General Public License for more details.
  12. You should have received a copy of the GNU General Public License
  13. along with GNU Classpath; see the file COPYING. If not, write to the
  14. Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
  15. 02110-1301 USA.
  16. Linking this library statically or dynamically with other modules is
  17. making a combined work based on this library. Thus, the terms and
  18. conditions of the GNU General Public License cover the whole
  19. combination.
  20. As a special exception, the copyright holders of this library give you
  21. permission to link this library with independent modules to produce an
  22. executable, regardless of the license terms of these independent
  23. modules, and to copy and distribute the resulting executable under
  24. terms of your choice, provided that you also meet, for each linked
  25. independent module, the terms and conditions of the license of that
  26. module. An independent module is a module which is not derived from
  27. or based on this library. If you modify this library, you may extend
  28. this exception to your version of the library, but you are not
  29. obligated to do so. If you do not wish to do so, delete this
  30. exception statement from your version. */
  31. package java.util.zip;
  32. import java.io.FilterOutputStream;
  33. import java.io.IOException;
  34. import java.io.OutputStream;
  35. /* Written using on-line Java Platform 1.2 API Specification
  36. * and JCL book.
  37. * Believed complete and correct.
  38. */
  39. /**
  40. * OutputStream that computes a checksum of data being written using a
  41. * supplied Checksum object.
  42. *
  43. * @see Checksum
  44. *
  45. * @author Tom Tromey
  46. * @date May 17, 1999
  47. */
  48. public class CheckedOutputStream extends FilterOutputStream
  49. {
  50. /**
  51. * Creates a new CheckInputStream on top of the supplied OutputStream
  52. * using the supplied Checksum.
  53. */
  54. public CheckedOutputStream (OutputStream out, Checksum cksum)
  55. {
  56. super (out);
  57. this.sum = cksum;
  58. }
  59. /**
  60. * Returns the Checksum object used. To get the data checksum computed so
  61. * far call <code>getChecksum.getValue()</code>.
  62. */
  63. public Checksum getChecksum ()
  64. {
  65. return sum;
  66. }
  67. /**
  68. * Writes one byte to the OutputStream and updates the Checksum.
  69. */
  70. public void write (int bval) throws IOException
  71. {
  72. out.write(bval);
  73. sum.update(bval);
  74. }
  75. /**
  76. * Writes the byte array to the OutputStream and updates the Checksum.
  77. */
  78. public void write (byte[] buf, int off, int len) throws IOException
  79. {
  80. out.write(buf, off, len);
  81. sum.update(buf, off, len);
  82. }
  83. /** The checksum object. */
  84. private Checksum sum;
  85. }