Uses of Package
org.bitcoinj.core

Packages that use org.bitcoinj.core

Package	Description
org.bitcoinj.core	The core package contains classes for network messages like Block and Transaction, peer connectivity via PeerGroup, block chain management and the Wallet class.
org.bitcoinj.crypto	The crypto package contains classes that work with key derivation algorithms like scrypt (passwords to AES keys), BIP 32 hierarchies (chains of keys from a root seed), X.509 utilities for the payment protocol and other general cryptography tasks.
org.bitcoinj.jni
org.bitcoinj.kits	High level wrapper APIs around the bitcoinj building blocks.
org.bitcoinj.net	Classes handling low level network management using either NIO (async io) or older style blocking sockets (useful for using SOCKS proxies, Tor, SSL etc).
org.bitcoinj.net.discovery	Classes that know how to discover peers in the P2P network using DNS, IRC or DNS via Tor (orchid).
org.bitcoinj.params	Network parameters encapsulate some of the differences between different Bitcoin networks such as the main network, the testnet, regtest mode, unit testing params and so on.
org.bitcoinj.protocols.channels	Micropayment channels allow for rapid tiny payments to be made to a third party once a channel has been set up, using some of the advanced features of the Bitcoin protocol.
org.bitcoinj.protocols.payments	The BIP70 payment protocol wraps Bitcoin transactions and adds various useful features like memos, refund addresses and authentication.
org.bitcoinj.script	Classes for working with and executing Bitcoin script programs, as embedded in inputs and outputs.
org.bitcoinj.signers	Transaction signers know how to calculate signatures over transactions in different contexts, for example, using local private keys or fetching them from remote servers.
org.bitcoinj.store	Block stores persist blockchain data downloaded from remote peers.
org.bitcoinj.testing	Various utilities for writing unit tests: also useful for testing your own code and apps that build on top of bitcoinj.
org.bitcoinj.uri	Parsing and handling of bitcoin: textual URIs as found in qr codes and web links.
org.bitcoinj.utils	Formatting monetary amounts, representing exchange rates, a program for loading Bitcoin Core saved block files, a class to control how bitcoinj uses threads and misc other utility classes that don't fit anywhere else.
org.bitcoinj.wallet	Classes that support the Wallet, which knows how to find and save transactions relevant to a set of keys or scripts, calculate balances, and spend money: the wallet has many features and can be extended in various ways, please refer to the website for documentation on how to use it.

Classes in org.bitcoinj.core used by org.bitcoinj.core

Class and Description
AbstractBlockChain An AbstractBlockChain holds a series of Block objects, links them together, and knows how to verify that the chain follows the rules of the NetworkParameters for this chain.
AbstractBlockChain.NewBlockType
AbstractPeerEventListener Convenience implementation of PeerEventListener.
Address A Bitcoin address looks like 1MsScoe2fTJoq4ZPdQgqyhgWeoNamYPevy and is derived from an elliptic curve public key plus a set of network parameters.
AddressFormatException
AddressMessage Represents an "addr" message on the P2P network, which contains broadcast IP addresses of other peers.
BitcoinSerializer.BitcoinPacketHeader
Block A block is a group of transactions, and is one of the fundamental data structures of the Bitcoin system.
BlockChainListener Implementors can be connected to a BlockChain and have its methods called when various things happen that modify the state of the chain, for example: new blocks being received, a re-org occurring, or the best chain head changing.
BloomFilter A Bloom filter is a probabilistic data structure which can be sent to another client so that it can avoid sending us transactions that aren't relevant to our set of keys.
BloomFilter.BloomUpdate The BLOOM_UPDATE_* constants control when the bloom filter is auto-updated by the peer using it as a filter, either never, for all outputs or only for pay-2-pubkey outputs (default)
ChildMessage Represents a Message type that can be contained within another Message.
Coin Represents a monetary Bitcoin value.
Context The Context object holds various objects and pieces of configuration that are scoped to a specific instantiation of bitcoinj for a specific network.
DumpedPrivateKey Parses and generates private keys in the form used by the Bitcoin "dumpprivkey" command.
ECKey Represents an elliptic curve public and (optionally) private key, usable for digital signatures but not encryption.
ECKey.ECDSASignature Groups the two components that make up a signature, and provides a way to encode to DER form, which is how ECDSA signatures are represented when embedded in other data structures in the Bitcoin protocol.
ECKey.MissingPrivateKeyException
EmptyMessage Parent class for header only messages that don't have a payload.
FilteredBlock A FilteredBlock is used to relay a block with its transactions filtered using a BloomFilter.
GetBlocksMessage Represents the "getblocks" P2P network message, which requests the hashes of the parts of the block chain we're missing.
GetDataMessage Represents the "getdata" P2P network message, which requests the contents of blocks or transactions given their hashes.
InsufficientMoneyException Thrown to indicate that you don't have enough money available to perform the requested operation.
InventoryItem
InventoryItem.Type
InventoryMessage Represents the "inv" P2P network message.
ListMessage Abstract superclass of classes with list based payload, ie InventoryMessage and GetDataMessage.
Message A Message is a data structure that can be serialized/deserialized using both the Bitcoin proprietary serialization format and built-in Java object serialization.
Monetary Classes implementing this interface represent a monetary value, such as a Bitcoin or fiat amount.
NetworkParameters NetworkParameters contains the data needed for working with an instantiation of a Bitcoin chain.
PartialMerkleTree A data structure that contains proofs of block inclusion for one or more transactions, in an efficient manner.
Peer A Peer handles the high level communication with a Bitcoin node, extending a PeerSocketHandler which handles low-level message (de)serialization.
PeerAddress A PeerAddress holds an IP address and port number representing the network location of a peer in the Bitcoin P2P network.
PeerEventListener Implementors can listen to events like blocks being downloaded/transactions being broadcast/connect/disconnects, they can pre-filter messages before they are procesesed by a Peer or PeerGroup, and they can provide transactions to remote peers when they ask for them.
PeerFilterProvider An interface which provides the information required to properly filter data downloaded from Peers.
PeerGroup Runs a set of connections to the P2P network, brings up connections to replace disconnected nodes and manages the interaction between them all.
PeerGroup.FilterRecalculateMode
PeerSocketHandler Handles high-level message (de)serialization for peers, acting as the bridge between the org.bitcoinj.net classes and Peer.
ProtocolException
PrunedException PrunedException is thrown in cases where a fully verifying node has deleted (pruned) old block data that turned out to be necessary for handling a re-org.
RejectMessage A message sent by nodes when a message we sent was rejected (ie a transaction had too little fee/was invalid/etc)
RejectMessage.RejectCode
ScriptException
Sha256Hash A Sha256Hash just wraps a byte[] so that equals and hashcode work correctly, allowing it to be used as keys in a map.
StoredBlock Wraps a Block object with extra data that can be derived from the block chain but is slow or inconvenient to calculate.
Transaction A transaction represents the movement of coins from some addresses to some other addresses.
Transaction.Purpose This enum describes the underlying reason the transaction was created.
Transaction.SigHash These constants are a part of a scriptSig signature on the inputs.
TransactionBag This interface is used to abstract the Wallet and the Transaction
TransactionBroadcast Represents a single transaction broadcast that we are performing.
TransactionBroadcast.ProgressCallback An interface for receiving progress information on the propagation of the tx, from 0.0 to 1.0
TransactionBroadcaster A general interface which declares the ability to broadcast transactions.
TransactionConfidence A TransactionConfidence object tracks data you can use to make a confidence decision about a transaction.
TransactionConfidence.ConfidenceType Describes the state of the transaction in general terms.
TransactionConfidence.Listener A confidence listener is informed when the level of TransactionConfidence is updated by something, like for example a Wallet.
TransactionConfidence.Listener.ChangeReason An enum that describes why a transaction confidence listener is being invoked (i.e.
TransactionConfidence.Source Information about where the transaction was first seen (network, sent direct from peer, created by ourselves).
TransactionInput A transfer of coins from one address to another creates a transaction in which the outputs can be claimed by the recipient in the input of another transaction.
TransactionInput.ConnectionResult
TransactionInput.ConnectMode
TransactionOutPoint This message is a reference or pointer to an output of a different transaction.
TransactionOutput A TransactionOutput message contains a scriptPubKey that controls who is able to spend its value.
TransactionOutputChanges TransactionOutputChanges represents a delta to the set of unspent outputs.
TxConfidenceTable Tracks transactions that are being announced across the network.
UTXO A UTXO message contains the information necessary to check a spending transaction.
UTXOProvider A UTXOProvider encapsulates functionality for returning unspent transaction outputs, for use by the wallet or other code that crafts spends.
UTXOProviderException
UTXOsMessage Message representing a list of unspent transaction outputs ("utxos"), returned in response to sending a GetUTXOsMessage ("getutxos").
VerificationException
VersionedChecksummedBytes In Bitcoin the following format is often used to represent some type of key:
VersionMessage A VersionMessage holds information exchanged during connection setup with another peer.
Wallet A Wallet stores keys and a record of transactions that send and receive value from those keys.
Wallet.BalanceType It's possible to calculate a wallets balance from multiple points of view.
Wallet.CompletionException
Wallet.MissingSigsMode Enumerates possible resolutions for missing signatures.
Wallet.SendRequest A SendRequest gives the wallet information about precisely how to send money to a recipient or set of recipients.
Wallet.SendResult A SendResult is returned to you as part of sending coins to a recipient.
WalletEventListener Implementors are called when the contents of the wallet changes, for instance due to receiving/sending money or a block chain re-organize.
WalletExtension An object implementing this interface can be added to a Wallet and provide arbitrary byte arrays that will be serialized alongside the wallet.
WrongNetworkException This exception is thrown by the Address class when you try and decode an address with a version code that isn't used by that network.

Classes in org.bitcoinj.core used by org.bitcoinj.crypto

Class and Description
AddressFormatException
ECKey Represents an elliptic curve public and (optionally) private key, usable for digital signatures but not encryption.
ECKey.ECDSASignature Groups the two components that make up a signature, and provides a way to encode to DER form, which is how ECDSA signatures are represented when embedded in other data structures in the Bitcoin protocol.
NetworkParameters NetworkParameters contains the data needed for working with an instantiation of a Bitcoin chain.
Sha256Hash A Sha256Hash just wraps a byte[] so that equals and hashcode work correctly, allowing it to be used as keys in a map.
Transaction.SigHash These constants are a part of a scriptSig signature on the inputs.
VerificationException
VersionedChecksummedBytes In Bitcoin the following format is often used to represent some type of key:

Classes in org.bitcoinj.core used by org.bitcoinj.jni

Class and Description
AbstractBlockChain.NewBlockType
Block A block is a group of transactions, and is one of the fundamental data structures of the Bitcoin system.
BlockChainListener Implementors can be connected to a BlockChain and have its methods called when various things happen that modify the state of the chain, for example: new blocks being received, a re-org occurring, or the best chain head changing.
Coin Represents a monetary Bitcoin value.
ECKey Represents an elliptic curve public and (optionally) private key, usable for digital signatures but not encryption.
FilteredBlock A FilteredBlock is used to relay a block with its transactions filtered using a BloomFilter.
GetDataMessage Represents the "getdata" P2P network message, which requests the contents of blocks or transactions given their hashes.
Message A Message is a data structure that can be serialized/deserialized using both the Bitcoin proprietary serialization format and built-in Java object serialization.
Peer A Peer handles the high level communication with a Bitcoin node, extending a PeerSocketHandler which handles low-level message (de)serialization.
PeerAddress A PeerAddress holds an IP address and port number representing the network location of a peer in the Bitcoin P2P network.
PeerEventListener Implementors can listen to events like blocks being downloaded/transactions being broadcast/connect/disconnects, they can pre-filter messages before they are procesesed by a Peer or PeerGroup, and they can provide transactions to remote peers when they ask for them.
ScriptException
Sha256Hash A Sha256Hash just wraps a byte[] so that equals and hashcode work correctly, allowing it to be used as keys in a map.
StoredBlock Wraps a Block object with extra data that can be derived from the block chain but is slow or inconvenient to calculate.
Transaction A transaction represents the movement of coins from some addresses to some other addresses.
TransactionConfidence A TransactionConfidence object tracks data you can use to make a confidence decision about a transaction.
TransactionConfidence.Listener A confidence listener is informed when the level of TransactionConfidence is updated by something, like for example a Wallet.
TransactionConfidence.Listener.ChangeReason An enum that describes why a transaction confidence listener is being invoked (i.e.
VerificationException
Wallet A Wallet stores keys and a record of transactions that send and receive value from those keys.
WalletEventListener Implementors are called when the contents of the wallet changes, for instance due to receiving/sending money or a block chain re-organize.

Classes in org.bitcoinj.core used by org.bitcoinj.kits

Class and Description
BlockChain A BlockChain implements the simplified payment verification mode of the Bitcoin protocol.
Context The Context object holds various objects and pieces of configuration that are scoped to a specific instantiation of bitcoinj for a specific network.
NetworkParameters NetworkParameters contains the data needed for working with an instantiation of a Bitcoin chain.
PeerAddress A PeerAddress holds an IP address and port number representing the network location of a peer in the Bitcoin P2P network.
PeerEventListener Implementors can listen to events like blocks being downloaded/transactions being broadcast/connect/disconnects, they can pre-filter messages before they are procesesed by a Peer or PeerGroup, and they can provide transactions to remote peers when they ask for them.
PeerGroup Runs a set of connections to the P2P network, brings up connections to replace disconnected nodes and manages the interaction between them all.
Wallet A Wallet stores keys and a record of transactions that send and receive value from those keys.
WalletExtension An object implementing this interface can be added to a Wallet and provide arbitrary byte arrays that will be serialized alongside the wallet.

Classes in org.bitcoinj.core used by org.bitcoinj.net

Class and Description
BloomFilter A Bloom filter is a probabilistic data structure which can be sent to another client so that it can avoid sending us transactions that aren't relevant to our set of keys.
PeerFilterProvider An interface which provides the information required to properly filter data downloaded from Peers.

Classes in org.bitcoinj.core used by org.bitcoinj.net.discovery

Class and Description
ECKey Represents an elliptic curve public and (optionally) private key, usable for digital signatures but not encryption.
NetworkParameters NetworkParameters contains the data needed for working with an instantiation of a Bitcoin chain.

Classes in org.bitcoinj.core used by org.bitcoinj.params

Class and Description
Address A Bitcoin address looks like 1MsScoe2fTJoq4ZPdQgqyhgWeoNamYPevy and is derived from an elliptic curve public key plus a set of network parameters.
Block A block is a group of transactions, and is one of the fundamental data structures of the Bitcoin system.
Coin Represents a monetary Bitcoin value.
ECKey Represents an elliptic curve public and (optionally) private key, usable for digital signatures but not encryption.
NetworkParameters NetworkParameters contains the data needed for working with an instantiation of a Bitcoin chain.
StoredBlock Wraps a Block object with extra data that can be derived from the block chain but is slow or inconvenient to calculate.
VerificationException

Classes in org.bitcoinj.core used by org.bitcoinj.protocols.channels

Class and Description
Coin Represents a monetary Bitcoin value.
ECKey Represents an elliptic curve public and (optionally) private key, usable for digital signatures but not encryption.
ECKey.KeyIsEncryptedException
InsufficientMoneyException Thrown to indicate that you don't have enough money available to perform the requested operation.
Sha256Hash A Sha256Hash just wraps a byte[] so that equals and hashcode work correctly, allowing it to be used as keys in a map.
Transaction A transaction represents the movement of coins from some addresses to some other addresses.
TransactionBroadcaster A general interface which declares the ability to broadcast transactions.
VerificationException
Wallet A Wallet stores keys and a record of transactions that send and receive value from those keys.
Wallet.SendRequest A SendRequest gives the wallet information about precisely how to send money to a recipient or set of recipients.
WalletExtension An object implementing this interface can be added to a Wallet and provide arbitrary byte arrays that will be serialized alongside the wallet.

Classes in org.bitcoinj.core used by org.bitcoinj.protocols.payments

Class and Description
Address A Bitcoin address looks like 1MsScoe2fTJoq4ZPdQgqyhgWeoNamYPevy and is derived from an elliptic curve public key plus a set of network parameters.
Coin Represents a monetary Bitcoin value.
NetworkParameters NetworkParameters contains the data needed for working with an instantiation of a Bitcoin chain.
Transaction A transaction represents the movement of coins from some addresses to some other addresses.
VerificationException
Wallet.SendRequest A SendRequest gives the wallet information about precisely how to send money to a recipient or set of recipients.

Classes in org.bitcoinj.core used by org.bitcoinj.script

Class and Description
Address A Bitcoin address looks like 1MsScoe2fTJoq4ZPdQgqyhgWeoNamYPevy and is derived from an elliptic curve public key plus a set of network parameters.
ECKey Represents an elliptic curve public and (optionally) private key, usable for digital signatures but not encryption.
NetworkParameters NetworkParameters contains the data needed for working with an instantiation of a Bitcoin chain.
ScriptException
Sha256Hash A Sha256Hash just wraps a byte[] so that equals and hashcode work correctly, allowing it to be used as keys in a map.
Transaction A transaction represents the movement of coins from some addresses to some other addresses.

Classes in org.bitcoinj.core used by org.bitcoinj.signers

Class and Description
ECKey Represents an elliptic curve public and (optionally) private key, usable for digital signatures but not encryption.
ECKey.ECDSASignature Groups the two components that make up a signature, and provides a way to encode to DER form, which is how ECDSA signatures are represented when embedded in other data structures in the Bitcoin protocol.
Sha256Hash A Sha256Hash just wraps a byte[] so that equals and hashcode work correctly, allowing it to be used as keys in a map.
Transaction A transaction represents the movement of coins from some addresses to some other addresses.
Wallet.MissingSigsMode Enumerates possible resolutions for missing signatures.

Classes in org.bitcoinj.core used by org.bitcoinj.store

Class and Description
Address A Bitcoin address looks like 1MsScoe2fTJoq4ZPdQgqyhgWeoNamYPevy and is derived from an elliptic curve public key plus a set of network parameters.
Context The Context object holds various objects and pieces of configuration that are scoped to a specific instantiation of bitcoinj for a specific network.
NetworkParameters NetworkParameters contains the data needed for working with an instantiation of a Bitcoin chain.
Sha256Hash A Sha256Hash just wraps a byte[] so that equals and hashcode work correctly, allowing it to be used as keys in a map.
StoredBlock Wraps a Block object with extra data that can be derived from the block chain but is slow or inconvenient to calculate.
StoredUndoableBlock Contains minimal data neccessary to disconnect/connect the transactions in the stored block at will.
Transaction A transaction represents the movement of coins from some addresses to some other addresses.
UTXO A UTXO message contains the information necessary to check a spending transaction.
UTXOProvider A UTXOProvider encapsulates functionality for returning unspent transaction outputs, for use by the wallet or other code that crafts spends.
UTXOProviderException
Wallet A Wallet stores keys and a record of transactions that send and receive value from those keys.
WalletExtension An object implementing this interface can be added to a Wallet and provide arbitrary byte arrays that will be serialized alongside the wallet.

Classes in org.bitcoinj.core used by org.bitcoinj.testing

Class and Description
AbstractBlockChain.NewBlockType
Address A Bitcoin address looks like 1MsScoe2fTJoq4ZPdQgqyhgWeoNamYPevy and is derived from an elliptic curve public key plus a set of network parameters.
Block A block is a group of transactions, and is one of the fundamental data structures of the Bitcoin system.
BlockChain A BlockChain implements the simplified payment verification mode of the Bitcoin protocol.
BloomFilter A Bloom filter is a probabilistic data structure which can be sent to another client so that it can avoid sending us transactions that aren't relevant to our set of keys.
Coin Represents a monetary Bitcoin value.
Context The Context object holds various objects and pieces of configuration that are scoped to a specific instantiation of bitcoinj for a specific network.
ECKey Represents an elliptic curve public and (optionally) private key, usable for digital signatures but not encryption.
Message A Message is a data structure that can be serialized/deserialized using both the Bitcoin proprietary serialization format and built-in Java object serialization.
NetworkParameters NetworkParameters contains the data needed for working with an instantiation of a Bitcoin chain.
Peer A Peer handles the high level communication with a Bitcoin node, extending a PeerSocketHandler which handles low-level message (de)serialization.
PeerGroup Runs a set of connections to the P2P network, brings up connections to replace disconnected nodes and manages the interaction between them all.
PeerSocketHandler Handles high-level message (de)serialization for peers, acting as the bridge between the org.bitcoinj.net classes and Peer.
Sha256Hash A Sha256Hash just wraps a byte[] so that equals and hashcode work correctly, allowing it to be used as keys in a map.
StoredBlock Wraps a Block object with extra data that can be derived from the block chain but is slow or inconvenient to calculate.
Transaction A transaction represents the movement of coins from some addresses to some other addresses.
TransactionBroadcast Represents a single transaction broadcast that we are performing.
TransactionBroadcaster A general interface which declares the ability to broadcast transactions.
VerificationException
VersionMessage A VersionMessage holds information exchanged during connection setup with another peer.
Wallet A Wallet stores keys and a record of transactions that send and receive value from those keys.
WalletExtension An object implementing this interface can be added to a Wallet and provide arbitrary byte arrays that will be serialized alongside the wallet.

Classes in org.bitcoinj.core used by org.bitcoinj.uri

Class and Description
Address A Bitcoin address looks like 1MsScoe2fTJoq4ZPdQgqyhgWeoNamYPevy and is derived from an elliptic curve public key plus a set of network parameters.
Coin Represents a monetary Bitcoin value.
NetworkParameters NetworkParameters contains the data needed for working with an instantiation of a Bitcoin chain.

Classes in org.bitcoinj.core used by org.bitcoinj.utils

Class and Description
Block A block is a group of transactions, and is one of the fundamental data structures of the Bitcoin system.
Coin Represents a monetary Bitcoin value.
Monetary Classes implementing this interface represent a monetary value, such as a Bitcoin or fiat amount.
NetworkParameters NetworkParameters contains the data needed for working with an instantiation of a Bitcoin chain.

Classes in org.bitcoinj.core used by org.bitcoinj.wallet

Class and Description
Address A Bitcoin address looks like 1MsScoe2fTJoq4ZPdQgqyhgWeoNamYPevy and is derived from an elliptic curve public key plus a set of network parameters.
BloomFilter A Bloom filter is a probabilistic data structure which can be sent to another client so that it can avoid sending us transactions that aren't relevant to our set of keys.
Coin Represents a monetary Bitcoin value.
ECKey Represents an elliptic curve public and (optionally) private key, usable for digital signatures but not encryption.
NetworkParameters NetworkParameters contains the data needed for working with an instantiation of a Bitcoin chain.
Transaction A transaction represents the movement of coins from some addresses to some other addresses.
TransactionInput A transfer of coins from one address to another creates a transaction in which the outputs can be claimed by the recipient in the input of another transaction.
TransactionOutPoint This message is a reference or pointer to an output of a different transaction.
TransactionOutput A TransactionOutput message contains a scriptPubKey that controls who is able to spend its value.
Wallet A Wallet stores keys and a record of transactions that send and receive value from those keys.