Java in a Nutshell, 5th Edition [Electronic resources]

This class is a byte input stream with an associated MessageDigest object. When bytes are read with any of the read( ) methods, those bytes are automatically passed to the update( ) method of the MessageDigest. When you have finished reading bytes, you can call the digest( ) method of the MessageDigest to obtain a message digest. If you want to compute a digest just for some of the bytes read from the stream, use on( ) to turn the digesting function on and off. Digesting is on by default; call on(false) to turn it off. See also DigestOutputStream and MessageDigest.

public class 
DigestInputStream  extends java.io.FilterInputStream {
// Public Constructors
public 
DigestInputStream (java.io.InputStream 
stream , MessageDigest 
digest );
// Public Instance Methods
public MessageDigest 
getMessageDigest ( );  
public void 
on (boolean 
on );  
public void 
setMessageDigest (MessageDigest 
digest );  
// Public Methods Overriding FilterInputStream
public int 
read ( ) throws java.io.IOException;  
public int 
read (byte[ ] 
b , int 
off , int 
len ) throws java.io.IOException;  
// Public Methods Overriding Object
public String 
toString ( );  
// Protected Instance Fields
protected MessageDigest 
digest ;  
}