GetHeadersMessage (bitcoinj-core 0.17-alpha5 API)

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

All Methods Static Methods Instance Methods Concrete Methods
Modifier and Type	Method	Description
`boolean`	`equals(java.lang.Object o)`	Compares two getheaders messages.
`int`	`hashCode()`
`static GetHeadersMessage`	`read(java.nio.ByteBuffer payload)`	Deserialize this message from a given payload.
`java.lang.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 Detail
  - GetHeadersMessage
```
public GetHeadersMessage(long protocolVersion,
                         BlockLocator locator,
                         Sha256Hash stopHash)
```
- Method Detail
  - read
```
public static GetHeadersMessage read(java.nio.ByteBuffer payload)
                              throws java.nio.BufferUnderflowException,
                                     ProtocolException
```
    Deserialize this message from a given payload.
    
    Parameters:
    
    payload - payload to deserialize from
    
    Returns:
    
    read message
    
    Throws:
    
    java.nio.BufferUnderflowException - if the read message extends beyond the remaining bytes of the payload
    
    ProtocolException
  - toString
```
public java.lang.String toString()
```
    Overrides:
    
    toString in class GetBlocksMessage
  - equals
```
public boolean equals(java.lang.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