Added in API level 1

Checksum

public interface Checksum

java.util.zip.Checksum


An interface representing a data checksum.

Summary

Public methods

abstract long getValue()

Returns the current checksum value.

abstract void reset()

Resets the checksum to its initial value.

default void update(byte[] b)

Updates the current checksum with the specified array of bytes.

default void update(ByteBuffer buffer)

Updates the current checksum with the bytes from the specified buffer.

abstract void update(byte[] b, int off, int len)

Updates the current checksum with the specified array of bytes.

abstract void update(int b)

Updates the current checksum with the specified byte.

Public methods

getValue

Added in API level 1
public abstract long getValue ()

Returns the current checksum value.

Returns
long the current checksum value

reset

Added in API level 1
public abstract void reset ()

Resets the checksum to its initial value.

update

Added in API level 34
public void update (byte[] b)

Updates the current checksum with the specified array of bytes.

Implementation Requirements:
  • This default implementation is equal to calling update(b, 0, b.length).
Parameters
b byte: the array of bytes to update the checksum with

Throws
NullPointerException if b is null

update

Added in API level 34
public void update (ByteBuffer buffer)

Updates the current checksum with the bytes from the specified buffer. The checksum is updated with the remaining bytes in the buffer, starting at the buffer's position. Upon return, the buffer's position will be updated to its limit; its limit will not have been changed.

API Note:
  • For best performance with DirectByteBuffer and other ByteBuffer implementations without a backing array implementers of this interface should override this method.
Implementation Requirements:
  • The default implementation has the following behavior.
    For ByteBuffers backed by an accessible byte array.
    update(buffer.array(),
            buffer.position() + buffer.arrayOffset(),
            buffer.remaining());
     
    For ByteBuffers not backed by an accessible byte array.
    byte[] b = new byte[Math.min(buffer.remaining(), 4096)];
     while (buffer.hasRemaining()) {
         int length = Math.min(buffer.remaining(), b.length);
         buffer.get(b, 0, length);
         update(b, 0, length);
     }
     
Parameters
buffer ByteBuffer: the ByteBuffer to update the checksum with

Throws
NullPointerException if buffer is null

update

Added in API level 1
public abstract void update (byte[] b, 
                int off, 
                int len)

Updates the current checksum with the specified array of bytes.

Parameters
b byte: the byte array to update the checksum with

off int: the start offset of the data

len int: the number of bytes to use for the update

update

Added in API level 1
public abstract void update (int b)

Updates the current checksum with the specified byte.

Parameters
b int: the byte to update the checksum with