Package org.apache.iceberg.util

Class HashWriter

java.lang.Object

java.io.Writer

org.apache.iceberg.util.HashWriter

All Implemented Interfaces:

Closeable, Flushable, Appendable, AutoCloseable

public class HashWriter
extends Writer

Writer implementation that uses a hashing function to produce a hash value based on the streamed bytes. The output of the writer is not preserved.

Field Summary

Fields inherited from class java.io.Writer

lock

Constructor Summary

Constructors

Constructor	Description
HashWriter(String hashAlgorithm, Charset charset)

Method Summary

Modifier and Type	Method	Description
void	close()
void	flush()
byte[]	getHash()	Calculates the final hash value.
void	write(char[] cbuf, int off, int len)

Methods inherited from class java.io.Writer

append, append, append, nullWriter, write, write, write, write

Methods inherited from class java.lang.Object

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

Constructor Details

HashWriter

public HashWriter(String hashAlgorithm,
 Charset charset)
           throws NoSuchAlgorithmException

Throws:

NoSuchAlgorithmException

Method Details

write

public void write(char[] cbuf,
 int off,
 int len)
           throws IOException

Specified by:

write in class Writer

Throws:

IOException

flush

public void flush()
           throws IOException

Specified by:

flush in interface Flushable

Specified by:

flush in class Writer

Throws:

IOException

close

public void close()
           throws IOException

Specified by:

close in interface AutoCloseable

Specified by:

close in interface Closeable

Specified by:

close in class Writer

Throws:

IOException

getHash

public byte[] getHash()

Calculates the final hash value. The underlying digest will be reset thus subsequent getHash() calls are not permitted.

Returns:

bytes of final hash value