Package org.bitcoinj.core

Class GetHeadersMessage

java.lang.Object

org.bitcoinj.core.BaseMessage

org.bitcoinj.core.GetBlocksMessage

org.bitcoinj.core.GetHeadersMessage

All Implemented Interfaces:

Message

public class GetHeadersMessage
extends GetBlocksMessage

The "getheaders" command is structurally identical to "getblocks", but has different meaning. On receiving this message a Bitcoin node returns matching blocks up to the limit, but without the bodies. It is useful as an optimization: when your wallet does not contain any keys created before a particular time, you don't have to download the bodies for those blocks because you know there are no relevant transactions.

Instances of this class are not safe for use by multiple threads.

Field Summary

Fields inherited from class org.bitcoinj.core.GetBlocksMessage

locator, stopHash, version

Fields inherited from interface org.bitcoinj.core.Message

MAX_SIZE

Constructor Summary

Constructors

Constructor	Description
GetHeadersMessage(long protocolVersion, BlockLocator locator, Sha256Hash stopHash)

Method Summary

Modifier and Type	Method	Description
boolean	equals(Object o)	Compares two getheaders messages.
int	hashCode()
static GetHeadersMessage	read(ByteBuffer payload)	Deserialize this message from a given payload.
String	toString()

Methods inherited from class org.bitcoinj.core.GetBlocksMessage

bitcoinSerializeToStream, getLocator, getStopHash

Methods inherited from class org.bitcoinj.core.BaseMessage

messageSize, serialize

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.bitcoinj.core.Message

bitcoinSerialize, getMessageSize, unsafeBitcoinSerialize

Constructor Details

GetHeadersMessage

public GetHeadersMessage(long protocolVersion,
 BlockLocator locator,
 Sha256Hash stopHash)

Method Details

read

public static GetHeadersMessage read(ByteBuffer payload)
                              throws BufferUnderflowException,
ProtocolException

Deserialize this message from a given payload.

Parameters:

payload - payload to deserialize from

Returns:

read message

Throws:

BufferUnderflowException - if the read message extends beyond the remaining bytes of the payload

ProtocolException

toString

public String toString()

Overrides:

toString in class GetBlocksMessage

equals

public boolean equals(Object o)

Compares two getheaders messages. Note that even though they are structurally identical a GetHeadersMessage will not compare equal to a GetBlocksMessage containing the same data.

Overrides:

equals in class GetBlocksMessage

hashCode

public int hashCode()

Overrides:

hashCode in class GetBlocksMessage