com.google.bitcoin.core

Class Sha256Hash

java.lang.Object

com.google.bitcoin.core.Sha256Hash

All Implemented Interfaces:

Serializable, Comparable

public class Sha256Hash
extends Object
implements Serializable, Comparable

A Sha256Hash just wraps a byte[] so that equals and hashcode work correctly, allowing it to be used as keys in a map. It also checks that the length is correct and provides a bit more type safety.

See Also:

Serialized Form

Field Summary

Fields

Modifier and Type	Field and Description
static Sha256Hash	ZERO_HASH

Constructor Summary

Constructors

Constructor and Description
Sha256Hash(byte[] rawHashBytes) Creates a Sha256Hash by wrapping the given byte array.
Sha256Hash(String hexString) Creates a Sha256Hash by decoding the given hex string.

Method Summary

Methods

Modifier and Type	Method and Description
int	compareTo(Object o)
static Sha256Hash	create(byte[] contents) Calculates the (one-time) hash of contents and returns it as a new wrapped hash.
static Sha256Hash	createDouble(byte[] contents) Calculates the hash of the hash of the contents.
Sha256Hash	duplicate()
boolean	equals(Object other) Returns true if the hashes are equal.
byte[]	getBytes()
int	hashCode() Hash code of the byte array as calculated by Object.hashCode().
static Sha256Hash	hashFileContents(File f) Returns a hash of the given files contents.
BigInteger	toBigInteger() Returns the bytes interpreted as a positive integer.
String	toString()

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Field Detail

ZERO_HASH

public static final Sha256Hash ZERO_HASH

Constructor Detail

Sha256Hash

public Sha256Hash(byte[] rawHashBytes)

Creates a Sha256Hash by wrapping the given byte array. It must be 32 bytes long.

Sha256Hash

public Sha256Hash(String hexString)

Creates a Sha256Hash by decoding the given hex string. It must be 64 characters long.

Method Detail

create

public static Sha256Hash create(byte[] contents)

Calculates the (one-time) hash of contents and returns it as a new wrapped hash.

createDouble

public static Sha256Hash createDouble(byte[] contents)

Calculates the hash of the hash of the contents. This is a standard operation in Bitcoin.

hashFileContents

public static Sha256Hash hashFileContents(File f)
                                   throws IOException

Returns a hash of the given files contents. Reads the file fully into memory before hashing so only use with small files.

Throws:

IOException

equals

public boolean equals(Object other)

Returns true if the hashes are equal.

Overrides:

equals in class Object

hashCode

public int hashCode()

Hash code of the byte array as calculated by Object.hashCode(). Note the difference between a SHA256 secure bytes and the type of quick/dirty bytes used by the Java hashCode method which is designed for use in bytes tables.

Overrides:

hashCode in class Object

toString

public String toString()

Overrides:

toString in class Object

toBigInteger

public BigInteger toBigInteger()

Returns the bytes interpreted as a positive integer.

getBytes

public byte[] getBytes()

duplicate

public Sha256Hash duplicate()

compareTo

public int compareTo(Object o)

Specified by:

compareTo in interface Comparable