Class CRC32

java.lang.Object

java.util.zip.CRC32

All Implemented Interfaces:: Checksum

public class CRC32 extends Object implements Checksum

A class that can be used to compute the CRC-32 of a data stream.

Passing a null argument to a method in this class will cause a NullPointerException to be thrown.

Since:: 1.1

Constructor Summary

Constructor	Description
`CRC32()`	Creates a new CRC32 object.

Method Summary

Modifier and Type	Method	Description
`long`	`getValue()`	Returns CRC-32 value.
`void`	`reset()`	Resets CRC-32 to initial value.
`void`	`update(byte[] b, int off, int len)`	Updates the CRC-32 checksum with the specified array of bytes.
`void`	`update(int b)`	Updates the CRC-32 checksum with the specified byte (the low eight bits of the argument b).
`void`	`update(ByteBuffer buffer)`	Updates the CRC-32 checksum with the bytes from the specified buffer.

Methods declared in class Object

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

Modifier and Type	Method	Description
`protected Object`	`clone()`	Creates and returns a copy of this object.
`boolean`	`equals(Object obj)`	Indicates whether some other object is "equal to" this one.
`protected void`	`finalize()`	Deprecated, for removal: This API element is subject to removal in a future version. Finalization is deprecated and subject to removal in a future release.
`final Class<?>`	`getClass()`	Returns the runtime class of this `Object`.
`int`	`hashCode()`	Returns a hash code value for this object.
`final void`	`notify()`	Wakes up a single thread that is waiting on this object's monitor.
`final void`	`notifyAll()`	Wakes up all threads that are waiting on this object's monitor.
`String`	`toString()`	Returns a string representation of the object.
`final void`	`wait()`	Causes the current thread to wait until it is awakened, typically by being notified or interrupted.
`final void`	`wait(long timeoutMillis)`	Causes the current thread to wait until it is awakened, typically by being notified or interrupted, or until a certain amount of real time has elapsed.
`final void`	`wait(long timeoutMillis, int nanos)`	Causes the current thread to wait until it is awakened, typically by being notified or interrupted, or until a certain amount of real time has elapsed.

Methods declared in interface Checksum

update

Modifier and Type	Method	Description
`default void`	`update(byte[] b)`	Updates the current checksum with the specified array of bytes.

Constructor Details

CRC32

public CRC32()

Creates a new CRC32 object.

Method Details

update

public void update(int b)

Updates the CRC-32 checksum with the specified byte (the low eight bits of the argument b).

Specified by:: update in interface Checksum
Parameters:: b - the byte to update the checksum with

update

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

Updates the CRC-32 checksum with the specified array of bytes.

Specified by:: update in interface Checksum
Parameters:: b - the byte array to update the checksum with; off - the start offset of the data; len - the number of bytes to use for the update
Throws:: ArrayIndexOutOfBoundsException - if off is negative, or len is negative, or off+len is negative or greater than the length of the array b.

update

public void update(ByteBuffer buffer)

Updates the CRC-32 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.

Specified by:: update in interface Checksum
Parameters:: buffer - the ByteBuffer to update the checksum with
Since:: 1.8

reset

public void reset()

Resets CRC-32 to initial value.

Specified by:: reset in interface Checksum

getValue

public long getValue()

Returns CRC-32 value.

Specified by:: getValue in interface Checksum
Returns:: the current checksum value

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