Package org.bitcoinj.core

Class Message

java.lang.Object
org.bitcoinj.core.Message
Direct Known Subclasses:
AddressMessage, Block, BloomFilter, ChildMessage, EmptyMessage, FeeFilterMessage, FilteredBlock, GetBlocksMessage, GetUTXOsMessage, HeadersMessage, ListMessage, MemoryPoolMessage, PartialMerkleTree, Ping, Pong, RejectMessage, UTXOsMessage, VersionMessage
public abstract class Message extends Object

A Message is a data structure that can be serialized/deserialized using the Bitcoin serialization format. Specific types of messages that are used both in the block chain, and on the wire, are derived from this class.

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

  • Field Details

    • MAX_SIZE

      public static final int MAX_SIZE
      See Also:

    • UNKNOWN_LENGTH

      public static final int UNKNOWN_LENGTH
      See Also:

    • offset

      protected int offset

    • cursor

      protected int cursor

    • length

      protected int length

    • payload

      protected byte[] payload

    • recached

      protected boolean recached

    • serializer

      protected MessageSerializer serializer

    • params

      protected NetworkParameters params

  • Constructor Details

    • Message

      protected Message()

    • Message

      protected Message(NetworkParameters params)

    • Message

      protected Message(NetworkParameters params, byte[] payload, int offset, MessageSerializer serializer, int length) throws ProtocolException
      Parameters:
      params - NetworkParameters object.
      payload - Bitcoin protocol formatted byte array containing message content.
      offset - The location of the first payload byte within the array.
      serializer - the serializer to use for this message.
      length - The length of message payload if known. Usually this is provided when deserializing of the wire as the length will be provided as part of the header. If unknown then set to Message.UNKNOWN_LENGTH
      Throws:
      ProtocolException

    • Message

      protected Message(NetworkParameters params, byte[] payload, int offset) throws ProtocolException
      Throws:
      ProtocolException

  • Method Details

    • parse

      protected abstract void parse() throws ProtocolException
      Throws:
      ProtocolException

    • unCache

      protected void unCache()

      To be called before any change of internal values including any setters. This ensures any cached byte array is removed.

      Child messages of this object(e.g. Transactions belonging to a Block) will not have their internal byte caches invalidated unless they are also modified internally.

    • adjustLength

      protected void adjustLength(int newArraySize, int adjustment)

    • isCached

      public boolean isCached()
      used for unit testing

    • isRecached

      public boolean isRecached()

    • setSerializer

      public void setSerializer(MessageSerializer serializer)
      Overrides the message serializer.
      Parameters:
      serializer - the new serializer

    • bitcoinSerialize

      public byte[] bitcoinSerialize()
      Returns a copy of the array returned by unsafeBitcoinSerialize(), which is safe to mutate. If you need extra performance and can guarantee you won't write to the array, you can use the unsafe version.
      Returns:
      a freshly allocated serialized byte array

    • unsafeBitcoinSerialize

      public byte[] unsafeBitcoinSerialize()

      Serialize this message to a byte array that conforms to the bitcoin wire protocol.

      This method may return the original byte array used to construct this message if the following conditions are met:

      1. 1) The message was parsed from a byte array with parseRetain = true
      2. 2) The message has not been modified
      3. 3) The array had an offset of 0 and no surplus bytes

      If condition 3 is not met then an copy of the relevant portion of the array will be returned. Otherwise a full serialize will occur. For this reason you should only use this API if you can guarantee you will treat the resulting array as read only.

      Returns:
      a byte array owned by this object, do NOT mutate it.

    • bitcoinSerialize

      public final void bitcoinSerialize(OutputStream stream) throws IOException
      Serialize this message to the provided OutputStream using the bitcoin wire format.
      Parameters:
      stream -
      Throws:
      IOException

    • bitcoinSerializeToStream

      protected void bitcoinSerializeToStream(OutputStream stream) throws IOException
      Serializes this message to the provided stream. If you just want the raw bytes use bitcoinSerialize().
      Throws:
      IOException

    • getHash

      public Sha256Hash getHash()
      This method is a NOP for all classes except Block and Transaction. It is only declared in Message so BitcoinSerializer can avoid 2 instanceof checks + a casting.

    • getMessageSize

      public final int getMessageSize()
      This returns a correct value by parsing the message.

    • readUint32

      protected long readUint32() throws ProtocolException
      Throws:
      ProtocolException

    • readInt64

      protected long readInt64() throws ProtocolException
      Throws:
      ProtocolException

    • readUint64

      protected BigInteger readUint64() throws ProtocolException
      Throws:
      ProtocolException

    • readVarInt

      protected VarInt readVarInt() throws ProtocolException
      Throws:
      ProtocolException

    • readVarInt

      protected VarInt readVarInt(int offset) throws ProtocolException
      Throws:
      ProtocolException

    • readBytes

      protected byte[] readBytes(int length) throws ProtocolException
      Throws:
      ProtocolException

    • readByte

      protected byte readByte() throws ProtocolException
      Throws:
      ProtocolException

    • readByteArray

      protected byte[] readByteArray() throws ProtocolException
      Throws:
      ProtocolException

    • readStr

      protected String readStr() throws ProtocolException
      Throws:
      ProtocolException

    • readHash

      protected Sha256Hash readHash() throws ProtocolException
      Throws:
      ProtocolException

    • hasMoreBytes

      protected boolean hasMoreBytes()

    • getParams

      public NetworkParameters getParams()
      Network parameters this message was created with.