Package org.apache.commons.io.input

# Class MessageDigestCalculatingInputStream.MessageDigestMaintainingObserver

java.lang.Object
org.apache.commons.io.input.ObservableInputStream.Observer
org.apache.commons.io.input.MessageDigestCalculatingInputStream.MessageDigestMaintainingObserver

Enclosing class:
  MessageDigestCalculatingInputStream

public static class MessageDigestCalculatingInputStream.MessageDigestMaintainingObserver extends ObservableInputStream.Observer
Maintains the message digest.

- ## Constructor Summary

  Constructors
  Constructor
  Description
  `MessageDigestMaintainingObserver(MessageDigest messageDigest)`
  Constructs an MessageDigestMaintainingObserver for the given MessageDigest.

- ## Method Summary

  Modifier and Type
  Method
  Description
  `void`
  `data(byte[] input, int offset, int length)`
  Called to indicate that `InputStream.read(byte[])`, or `InputStream.read(byte[], int, int)` have been called, and are about to invoke data.
  `void`
  `data(int input)`
  Called to indicate, that `InputStream.read()` has been invoked on the `ObservableInputStream`, and will return a value.

  ### Methods inherited from class org.apache.commons.io.input.ObservableInputStream.Observer

  `closed, error, finished`

  ### Methods inherited from class java.lang.Object

  `clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait`

- ## Constructor Details

  - ### MessageDigestMaintainingObserver

    public MessageDigestMaintainingObserver(MessageDigest messageDigest)
    Constructs an MessageDigestMaintainingObserver for the given MessageDigest.
    Parameters:
      `messageDigest` - the message digest to use
    Throws:
      `NullPointerException` - if messageDigest is null.

- ## Method Details

  - ### data

    public void data(byte[] input, int offset, int length) throws IOException
    Description copied from class: `ObservableInputStream.Observer`
    Called to indicate that `InputStream.read(byte[])`, or `InputStream.read(byte[], int, int)` have been called, and are about to invoke data.
    Overrides:
      `data` in class `ObservableInputStream.Observer`
    Parameters:
      `input` - The byte array, which has been passed to the read call, and where data has been stored.
      `offset` - The offset within the byte array, where data has been stored.
      `length` - The number of bytes, which have been stored in the byte array.
    Throws:
      `IOException` - if an I/O error occurs.

  - ### data

    public void data(int input) throws IOException
    Description copied from class: `ObservableInputStream.Observer`
    Called to indicate, that `InputStream.read()` has been invoked on the `ObservableInputStream`, and will return a value.
    Overrides:
      `data` in class `ObservableInputStream.Observer`
    Parameters:
      `input` - The value, which is being returned. This will never be -1 (EOF), because, in that case, `ObservableInputStream.Observer.finished()` will be invoked instead.
    Throws:
      `IOException` - if an I/O error occurs.