VersionMessage (bitcoinj 0.14 API)

java.lang.Object
- org.bitcoinj.core.Message
- - org.bitcoinj.core.VersionMessage

```
public class VersionMessage
extends Message
```
A VersionMessage holds information exchanged during connection setup with another peer. Most of the fields are not particularly interesting. The subVer field, since BIP 14, acts as a User-Agent string would. You can and should append to or change the subVer for your own software so other implementations can identify it, and you can look at the subVer field received from other nodes to see what they are running.

After creating yourself a VersionMessage, you can pass it to PeerGroup.setVersionMessage(VersionMessage) to ensure it will be used for each new connection.

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

Field Summary

Fields
Modifier and Type	Field and Description
`long`	`bestHeight` How many blocks are in the chain, according to the other side.
`static String`	`BITCOINJ_VERSION` The version of this library release, as a string.
`int`	`clientVersion` The version number of the protocol spoken.
`static String`	`LIBRARY_SUBVER` The value that is prepended to the subVer field of this application.
`long`	`localServices` Flags defining what optional services are supported.
`PeerAddress`	`myAddr` What the other side believes the address of this program is.
`static int`	`NODE_GETUTXOS` A flag that denotes whether the peer supports the getutxos message or not.
`static int`	`NODE_NETWORK` A services flag that denotes whether the peer has a copy of the block chain or not.
`boolean`	`relayTxesBeforeFilter` Whether or not to relay tx invs before a filter is received.
`String`	`subVer` User-Agent as defined in BIP 14.
`PeerAddress`	`theirAddr` What the other side believes their own address is.
`long`	`time` What the other side believes the current time to be, in seconds.

Fields inherited from class org.bitcoinj.core.Message
cursor, length, MAX_SIZE, offset, params, payload, protocolVersion, recached, serializer, UNKNOWN_LENGTH

Constructor Summary

Constructors
Constructor and Description
`VersionMessage(NetworkParameters params, byte[] payload)`
`VersionMessage(NetworkParameters params, int newBestHeight)`

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method and Description
`void`	`appendToSubVer(String name, String version, String comments)` Appends the given user-agent information to the subVer field.
`void`	`bitcoinSerializeToStream(OutputStream buf)` Serializes this message to the provided stream.
`VersionMessage`	`duplicate()`
`boolean`	`equals(Object o)`
`boolean`	`hasBlockChain()` Returns true if the version message indicates the sender has a full copy of the block chain, or if it's running in client mode (only has the headers).
`int`	`hashCode()`
`boolean`	`isBloomFilteringSupported()` Returns true if the clientVersion field is >= FilteredBlock.MIN_PROTOCOL_VERSION.
`boolean`	`isGetUTXOsSupported()` Returns true if the protocol version and service bits both indicate support for the getutxos message.
`boolean`	`isPingPongSupported()` Returns true if the clientVersion field is >= Pong.MIN_PROTOCOL_VERSION.
`protected void`	`parse()`
`String`	`toString()`

Methods inherited from class org.bitcoinj.core.Message
adjustLength, bitcoinSerialize, bitcoinSerialize, getHash, getMessageSize, getParams, hasMoreBytes, isCached, isRecached, readByteArray, readBytes, readHash, readInt64, readStr, readUint32, readUint64, readVarInt, readVarInt, unCache, unsafeBitcoinSerialize

Methods inherited from class java.lang.Object
clone, finalize, getClass, notify, notifyAll, wait, wait, wait

- Field Detail
  - NODE_NETWORK
```
public static final int NODE_NETWORK
```
    A services flag that denotes whether the peer has a copy of the block chain or not.
    
    See Also:
    
    Constant Field Values
  - NODE_GETUTXOS
```
public static final int NODE_GETUTXOS
```
    A flag that denotes whether the peer supports the getutxos message or not.
    
    See Also:
    
    Constant Field Values
  - clientVersion
```
public int clientVersion
```
    The version number of the protocol spoken.
  - localServices
```
public long localServices
```
    Flags defining what optional services are supported.
  - time
```
public long time
```
    What the other side believes the current time to be, in seconds.
  - myAddr
```
public PeerAddress myAddr
```
    What the other side believes the address of this program is. Not used.
  - theirAddr
```
public PeerAddress theirAddr
```
    What the other side believes their own address is. Not used.
  - subVer
```
public String subVer
```
    User-Agent as defined in BIP 14. Bitcoin Core sets it to something like "/Satoshi:0.9.1/".
  - bestHeight
```
public long bestHeight
```
    How many blocks are in the chain, according to the other side.
  - relayTxesBeforeFilter
```
public boolean relayTxesBeforeFilter
```
    Whether or not to relay tx invs before a filter is received. See BIP 37.
  - BITCOINJ_VERSION
```
public static final String BITCOINJ_VERSION
```
    The version of this library release, as a string.
    
    See Also:
    
    Constant Field Values
  - LIBRARY_SUBVER
```
public static final String LIBRARY_SUBVER
```
    The value that is prepended to the subVer field of this application.
    
    See Also:
    
    Constant Field Values
- Constructor Detail
  - VersionMessage
```
public VersionMessage(NetworkParameters params,
                      byte[] payload)
               throws ProtocolException
```
    Throws:
    
    ProtocolException
  - VersionMessage
```
public VersionMessage(NetworkParameters params,
                      int newBestHeight)
```
- Method Detail
  - parse
```
protected void parse()
              throws ProtocolException
```
    Specified by:
    
    parse in class Message
    
    Throws:
    
    ProtocolException
  - bitcoinSerializeToStream
```
public void bitcoinSerializeToStream(OutputStream buf)
                              throws IOException
```
    Description copied from class: Message
    
    Serializes this message to the provided stream. If you just want the raw bytes use bitcoinSerialize().
    
    Overrides:
    
    bitcoinSerializeToStream in class Message
    
    Throws:
    
    IOException
  - hasBlockChain
```
public boolean hasBlockChain()
```
    Returns true if the version message indicates the sender has a full copy of the block chain, or if it's running in client mode (only has the headers).
  - equals
```
public boolean equals(Object o)
```
    Overrides:
    
    equals in class Object
  - hashCode
```
public int hashCode()
```
    Overrides:
    
    hashCode in class Object
  - toString
```
public String toString()
```
    Overrides:
    
    toString in class Object
  - duplicate
```
public VersionMessage duplicate()
```
  - appendToSubVer
```
public void appendToSubVer(String name,
                           String version,
                           @Nullable
                           String comments)
```
    Appends the given user-agent information to the subVer field. The subVer is composed of a series of name:version pairs separated by slashes in the form of a path. For example a typical subVer field for bitcoinj users might look like "/bitcoinj:0.13/MultiBit:1.2/" where libraries come further to the left.
    There can be as many components as you feel a need for, and the version string can be anything, but it is recommended to use A.B.C where A = major, B = minor and C = revision for software releases, and dates for auto-generated source repository snapshots. A valid subVer begins and ends with a slash, therefore name and version are not allowed to contain such characters.
    Anything put in the "comments" field will appear in brackets and may be used for platform info, or anything else. For example, calling appendToSubVer("MultiBit", "1.0", "Windows") will result in a subVer being set of "/bitcoinj:1.0/MultiBit:1.0(Windows)/". Therefore the / ( and ) characters are reserved in all these components. If you don't want to add a comment (recommended), pass null.
    See BIP 14 for more information.
    
    Parameters:
    
    comments - Optional (can be null) platform or other node specific information.
    
    Throws:
    
    IllegalArgumentException - if name, version or comments contains invalid characters.
  - isPingPongSupported
```
public boolean isPingPongSupported()
```
    Returns true if the clientVersion field is >= Pong.MIN_PROTOCOL_VERSION. If it is then ping() is usable.
  - isBloomFilteringSupported
```
public boolean isBloomFilteringSupported()
```
    Returns true if the clientVersion field is >= FilteredBlock.MIN_PROTOCOL_VERSION. If it is then Bloom filtering is available and the memory pool of the remote peer will be queried when the downloadData property is true.
  - isGetUTXOsSupported
```
public boolean isGetUTXOsSupported()
```
    Returns true if the protocol version and service bits both indicate support for the getutxos message.

Class VersionMessage

Field Summary

Fields inherited from class org.bitcoinj.core.Message

Constructor Summary

Method Summary

Methods inherited from class org.bitcoinj.core.Message

Methods inherited from class java.lang.Object

Field Detail

NODE_NETWORK

NODE_GETUTXOS

clientVersion

localServices

time

myAddr

theirAddr

subVer

bestHeight

relayTxesBeforeFilter

BITCOINJ_VERSION

LIBRARY_SUBVER

Constructor Detail

VersionMessage

VersionMessage

Method Detail

parse

bitcoinSerializeToStream

hasBlockChain

equals

hashCode

toString

duplicate

appendToSubVer

isPingPongSupported

isBloomFilteringSupported

isGetUTXOsSupported