NetworkParameters (core 0.15 API)

java.lang.Object
- org.bitcoinj.core.NetworkParameters

Direct Known Subclasses:

AbstractBitcoinNetParams
```
public abstract class NetworkParameters
extends java.lang.Object
```
NetworkParameters contains the data needed for working with an instantiation of a Bitcoin chain.

This is an abstract class, concrete instantiations can be found in the params package. There are four: one for the main network (MainNetParams), one for the public test network, and two others that are intended for unit testing and local app development purposes. Although this class contains some aliases for them, you are encouraged to call the static get() methods on each specific params class directly.

Nested Class Summary

Nested Classes
Modifier and Type Class and Description

static class NetworkParameters.ProtocolVersion

Nested Classes
Modifier and Type	Class and Description
`static class`	`NetworkParameters.ProtocolVersion`

Field Summary

Fields
Modifier and Type	Field and Description
`protected int`	`addressHeader`
`protected int[]`	`addrSeeds`
`protected byte[]`	`alertSigningKey`
`static int`	`BIP16_ENFORCE_TIME` Blocks with a timestamp after this should enforce BIP 16, aka "Pay to script hash".
`protected int`	`bip32HeaderP2PKHpriv`
`protected int`	`bip32HeaderP2PKHpub`
`protected int`	`bip32HeaderP2WPKHpriv`
`protected int`	`bip32HeaderP2WPKHpub`
`protected java.util.Map<java.lang.Integer,Sha256Hash>`	`checkpoints`
`protected MessageSerializer`	`defaultSerializer`
`protected java.lang.String[]`	`dnsSeeds`
`protected int`	`dumpedPrivateKeyHeader`
`protected Block`	`genesisBlock`
`protected HttpDiscovery.Details[]`	`httpSeeds`
`protected java.lang.String`	`id` See getId().
`static java.lang.String`	`ID_MAINNET` The string returned by getId() for the main, production network where people trade things.
`static java.lang.String`	`ID_REGTEST` The string returned by getId() for regtest mode.
`static java.lang.String`	`ID_TESTNET` The string returned by getId() for the testnet.
`static java.lang.String`	`ID_UNITTESTNET` Unit test network.
`protected int`	`interval`
`static int`	`INTERVAL`
`protected int`	`majorityEnforceBlockUpgrade` Used to check majorities for block version upgrade
`protected int`	`majorityRejectBlockOutdated`
`protected int`	`majorityWindow`
`static long`	`MAX_COINS` The maximum number of coins to be generated
`static Coin`	`MAX_MONEY` The maximum money to be generated
`protected java.math.BigInteger`	`maxTarget`
`protected int`	`p2shHeader`
`protected long`	`packetMagic`
`static java.lang.String`	`PAYMENT_PROTOCOL_ID_MAINNET` The string used by the payment protocol to represent the main net.
`static java.lang.String`	`PAYMENT_PROTOCOL_ID_REGTEST`
`static java.lang.String`	`PAYMENT_PROTOCOL_ID_TESTNET` The string used by the payment protocol to represent the test net.
`static java.lang.String`	`PAYMENT_PROTOCOL_ID_UNIT_TESTS` The string used by the payment protocol to represent unit testing (note that this is non-standard).
`protected int`	`port`
`static byte[]`	`SATOSHI_KEY` The alert signing key originally owned by Satoshi, and now passed on to Gavin along with a few others.
`protected java.lang.String`	`segwitAddressHrp`
`protected int`	`spendableCoinbaseDepth` The depth of blocks required for a coinbase transaction to be spendable.
`protected int`	`subsidyDecreaseBlockCount`
`static int`	`TARGET_SPACING`
`static int`	`TARGET_TIMESPAN`
`protected int`	`targetTimespan`

Constructor Summary

Constructors
Modifier Constructor and Description

protected NetworkParameters()

Constructors
Modifier	Constructor and Description
`protected`	`NetworkParameters()`

Method Summary

All Methods Static Methods Instance Methods Abstract Methods Concrete Methods
Modifier and Type	Method and Description
`boolean`	`allowEmptyPeerChain()` If we are running in testnet-in-a-box mode, we allow connections to nodes with 0 non-genesis blocks.
`abstract void`	`checkDifficultyTransitions(StoredBlock storedPrev, Block next, BlockStore blockStore)` Throws an exception if the block's difficulty is not correct.
`boolean`	`equals(java.lang.Object o)`
`static NetworkParameters`	`fromID(java.lang.String id)` Returns the network parameters for the given string ID or NULL if not recognized.
`static NetworkParameters`	`fromPmtProtocolID(java.lang.String pmtProtocolId)` Returns the network parameters for the given string paymentProtocolID or NULL if not recognized.
`int`	`getAddressHeader()` First byte of a base58 encoded address.
`int[]`	`getAddrSeeds()` Returns IP address of active peers.
`byte[]`	`getAlertSigningKey()` The key used to sign `AlertMessage`s.
`int`	`getBip32HeaderP2PKHpriv()` Returns the 4 byte header for BIP32 wallet P2PKH - private key part.
`int`	`getBip32HeaderP2PKHpub()` Returns the 4 byte header for BIP32 wallet P2PKH - public key part.
`int`	`getBip32HeaderP2WPKHpriv()` Returns the 4 byte header for BIP32 wallet P2WPKH - private key part.
`int`	`getBip32HeaderP2WPKHpub()` Returns the 4 byte header for BIP32 wallet P2WPKH - public key part.
`java.util.EnumSet<Block.VerifyFlag>`	`getBlockVerificationFlags(Block block, VersionTally tally, java.lang.Integer height)` The flags indicating which block validation tests should be applied to the given block.
`MessageSerializer`	`getDefaultSerializer()` Return the default serializer for this network.
`java.lang.String[]`	`getDnsSeeds()` Returns DNS names that when resolved, give IP addresses of active peers.
`int`	`getDumpedPrivateKeyHeader()` First byte of a base58 encoded dumped private key.
`Block`	`getGenesisBlock()` Genesis block for this chain.
`HttpDiscovery.Details[]`	`getHttpSeeds()` Returns discovery objects for seeds implementing the Cartographer protocol.
`java.lang.String`	`getId()` A Java package style string acting as unique ID for these parameters
`int`	`getInterval()` How many blocks pass between difficulty adjustment periods.
`int`	`getMajorityEnforceBlockUpgrade()` The number of blocks in the last `getMajorityWindow()` blocks at which to trigger a notice to the user to upgrade their client, where the client does not understand those blocks.
`int`	`getMajorityRejectBlockOutdated()` The number of blocks in the last `getMajorityWindow()` blocks at which to enforce the requirement that all new blocks are of the newer type (i.e.
`int`	`getMajorityWindow()` The sampling window from which the version numbers of blocks are taken in order to determine if a new block version is now the majority.
`abstract Coin`	`getMaxMoney()` Returns the number of coins that will be produced in total, on this network.
`java.math.BigInteger`	`getMaxTarget()` Maximum target represents the easiest allowable proof of work.
`abstract Coin`	`getMinNonDustOutput()` Any standard (ie P2PKH) output smaller than this value will most likely be rejected by the network.
`abstract MonetaryFormat`	`getMonetaryFormat()` The monetary object for this currency.
`int`	`getP2SHHeader()` First byte of a base58 encoded P2SH address.
`long`	`getPacketMagic()` The header bytes that identify the start of a packet on this network.
`abstract java.lang.String`	`getPaymentProtocolId()`
`int`	`getPort()` Default TCP port on which to connect to nodes.
`abstract int`	`getProtocolVersionNum(NetworkParameters.ProtocolVersion version)`
`java.lang.String`	`getSegwitAddressHrp()` Human readable part of bech32 encoded segwit address.
`abstract BitcoinSerializer`	`getSerializer(boolean parseRetain)` Construct and return a custom serializer.
`int`	`getSpendableCoinbaseDepth()`
`int`	`getSubsidyDecreaseBlockCount()`
`int`	`getTargetTimespan()` How much time in seconds is supposed to pass between "interval" blocks.
`java.util.EnumSet<Script.VerifyFlag>`	`getTransactionVerificationFlags(Block block, Transaction transaction, VersionTally tally, java.lang.Integer height)` The flags indicating which script validation tests should be applied to the given transaction.
`abstract java.lang.String`	`getUriScheme()` Scheme part for URIs, for example "bitcoin".
`int`	`hashCode()`
`abstract boolean`	`hasMaxMoney()` Returns whether this network has a maximum number of coins (finite supply) or not.
`boolean`	`isCheckpoint(int height)` Returns true if the given height has a recorded checkpoint.
`boolean`	`passesCheckpoint(int height, Sha256Hash hash)` Returns true if the block height is either not a checkpoint, or is a checkpoint and the hash matches.

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

- Field Detail
  - SATOSHI_KEY
```
public static final byte[] SATOSHI_KEY
```
    The alert signing key originally owned by Satoshi, and now passed on to Gavin along with a few others.
  - ID_MAINNET
```
public static final java.lang.String ID_MAINNET
```
    The string returned by getId() for the main, production network where people trade things.
    
    See Also:
    
    Constant Field Values
  - ID_TESTNET
```
public static final java.lang.String ID_TESTNET
```
    The string returned by getId() for the testnet.
    
    See Also:
    
    Constant Field Values
  - ID_REGTEST
```
public static final java.lang.String ID_REGTEST
```
    The string returned by getId() for regtest mode.
    
    See Also:
    
    Constant Field Values
  - ID_UNITTESTNET
```
public static final java.lang.String ID_UNITTESTNET
```
    Unit test network.
    
    See Also:
    
    Constant Field Values
  - PAYMENT_PROTOCOL_ID_MAINNET
```
public static final java.lang.String PAYMENT_PROTOCOL_ID_MAINNET
```
    The string used by the payment protocol to represent the main net.
    
    See Also:
    
    Constant Field Values
  - PAYMENT_PROTOCOL_ID_TESTNET
```
public static final java.lang.String PAYMENT_PROTOCOL_ID_TESTNET
```
    The string used by the payment protocol to represent the test net.
    
    See Also:
    
    Constant Field Values
  - PAYMENT_PROTOCOL_ID_UNIT_TESTS
```
public static final java.lang.String PAYMENT_PROTOCOL_ID_UNIT_TESTS
```
    The string used by the payment protocol to represent unit testing (note that this is non-standard).
    
    See Also:
    
    Constant Field Values
  - PAYMENT_PROTOCOL_ID_REGTEST
```
public static final java.lang.String PAYMENT_PROTOCOL_ID_REGTEST
```
    See Also:
    
    Constant Field Values
  - genesisBlock
```
protected Block genesisBlock
```
  - maxTarget
```
protected java.math.BigInteger maxTarget
```
  - port
```
protected int port
```
  - packetMagic
```
protected long packetMagic
```
  - addressHeader
```
protected int addressHeader
```
  - p2shHeader
```
protected int p2shHeader
```
  - dumpedPrivateKeyHeader
```
protected int dumpedPrivateKeyHeader
```
  - segwitAddressHrp
```
protected java.lang.String segwitAddressHrp
```
  - interval
```
protected int interval
```
  - targetTimespan
```
protected int targetTimespan
```
  - alertSigningKey
```
protected byte[] alertSigningKey
```
  - bip32HeaderP2PKHpub
```
protected int bip32HeaderP2PKHpub
```
  - bip32HeaderP2PKHpriv
```
protected int bip32HeaderP2PKHpriv
```
  - bip32HeaderP2WPKHpub
```
protected int bip32HeaderP2WPKHpub
```
  - bip32HeaderP2WPKHpriv
```
protected int bip32HeaderP2WPKHpriv
```
  - majorityEnforceBlockUpgrade
```
protected int majorityEnforceBlockUpgrade
```
    Used to check majorities for block version upgrade
  - majorityRejectBlockOutdated
```
protected int majorityRejectBlockOutdated
```
  - majorityWindow
```
protected int majorityWindow
```
  - id
```
protected java.lang.String id
```
    See getId(). This may be null for old deserialized wallets. In that case we derive it heuristically by looking at the port number.
  - spendableCoinbaseDepth
```
protected int spendableCoinbaseDepth
```
    The depth of blocks required for a coinbase transaction to be spendable.
  - subsidyDecreaseBlockCount
```
protected int subsidyDecreaseBlockCount
```
  - dnsSeeds
```
protected java.lang.String[] dnsSeeds
```
  - addrSeeds
```
protected int[] addrSeeds
```
  - httpSeeds
```
protected HttpDiscovery.Details[] httpSeeds
```
  - checkpoints
```
protected java.util.Map<java.lang.Integer,Sha256Hash> checkpoints
```
  - defaultSerializer
```
protected transient MessageSerializer defaultSerializer
```
  - TARGET_TIMESPAN
```
public static final int TARGET_TIMESPAN
```
    See Also:
    
    Constant Field Values
  - TARGET_SPACING
```
public static final int TARGET_SPACING
```
    See Also:
    
    Constant Field Values
  - INTERVAL
```
public static final int INTERVAL
```
    See Also:
    
    Constant Field Values
  - BIP16_ENFORCE_TIME
```
public static final int BIP16_ENFORCE_TIME
```
    Blocks with a timestamp after this should enforce BIP 16, aka "Pay to script hash". This BIP changed the network rules in a soft-forking manner, that is, blocks that don't follow the rules are accepted but not mined upon and thus will be quickly re-orged out as long as the majority are enforcing the rule.
    
    See Also:
    
    Constant Field Values
  - MAX_COINS
```
public static final long MAX_COINS
```
    The maximum number of coins to be generated
    
    See Also:
    
    Constant Field Values
  - MAX_MONEY
```
public static final Coin MAX_MONEY
```
    The maximum money to be generated
- Constructor Detail
  - NetworkParameters
```
protected NetworkParameters()
```
- Method Detail
  - getId
```
public java.lang.String getId()
```
    A Java package style string acting as unique ID for these parameters
  - getPaymentProtocolId
```
public abstract java.lang.String getPaymentProtocolId()
```
  - equals
```
public boolean equals(java.lang.Object o)
```
    Overrides:
    
    equals in class java.lang.Object
  - hashCode
```
public int hashCode()
```
    Overrides:
    
    hashCode in class java.lang.Object
  - fromID
```
@Nullable
public static NetworkParameters fromID(java.lang.String id)
```
    Returns the network parameters for the given string ID or NULL if not recognized.
  - fromPmtProtocolID
```
@Nullable
public static NetworkParameters fromPmtProtocolID(java.lang.String pmtProtocolId)
```
    Returns the network parameters for the given string paymentProtocolID or NULL if not recognized.
  - getSpendableCoinbaseDepth
```
public int getSpendableCoinbaseDepth()
```
  - checkDifficultyTransitions
```
public abstract void checkDifficultyTransitions(StoredBlock storedPrev,
                                                Block next,
                                                BlockStore blockStore)
                                         throws VerificationException,
                                                BlockStoreException
```
    Throws an exception if the block's difficulty is not correct.
    
    Throws:
    
    VerificationException - if the block's difficulty is not correct.
    
    BlockStoreException
  - passesCheckpoint
```
public boolean passesCheckpoint(int height,
                                Sha256Hash hash)
```
    Returns true if the block height is either not a checkpoint, or is a checkpoint and the hash matches.
  - isCheckpoint
```
public boolean isCheckpoint(int height)
```
    Returns true if the given height has a recorded checkpoint.
  - getSubsidyDecreaseBlockCount
```
public int getSubsidyDecreaseBlockCount()
```
  - getDnsSeeds
```
public java.lang.String[] getDnsSeeds()
```
    Returns DNS names that when resolved, give IP addresses of active peers.
  - getAddrSeeds
```
public int[] getAddrSeeds()
```
    Returns IP address of active peers.
  - getHttpSeeds
```
public HttpDiscovery.Details[] getHttpSeeds()
```
    Returns discovery objects for seeds implementing the Cartographer protocol. See HttpDiscovery for more info.
  - getGenesisBlock
```
public Block getGenesisBlock()
```
    Genesis block for this chain.
    
    The first block in every chain is a well known constant shared between all Bitcoin implementations. For a block to be valid, it must be eventually possible to work backwards to the genesis block by following the prevBlockHash pointers in the block headers.
    
    The genesis blocks for both test and main networks contain the timestamp of when they were created, and a message in the coinbase transaction. It says, "The Times 03/Jan/2009 Chancellor on brink of second bailout for banks".
  - getPort
```
public int getPort()
```
    Default TCP port on which to connect to nodes.
  - getPacketMagic
```
public long getPacketMagic()
```
    The header bytes that identify the start of a packet on this network.
  - getAddressHeader
```
public int getAddressHeader()
```
    First byte of a base58 encoded address. See LegacyAddress. This is the same as acceptableAddressCodes[0] and is the one used for "normal" addresses. Other types of address may be encountered with version codes found in the acceptableAddressCodes array.
  - getP2SHHeader
```
public int getP2SHHeader()
```
    First byte of a base58 encoded P2SH address. P2SH addresses are defined as part of BIP0013.
  - getDumpedPrivateKeyHeader
```
public int getDumpedPrivateKeyHeader()
```
    First byte of a base58 encoded dumped private key. See DumpedPrivateKey.
  - getSegwitAddressHrp
```
public java.lang.String getSegwitAddressHrp()
```
    Human readable part of bech32 encoded segwit address.
  - getTargetTimespan
```
public int getTargetTimespan()
```
    How much time in seconds is supposed to pass between "interval" blocks. If the actual elapsed time is significantly different from this value, the network difficulty formula will produce a different value. Both test and main Bitcoin networks use 2 weeks (1209600 seconds).
  - allowEmptyPeerChain
```
public boolean allowEmptyPeerChain()
```
    If we are running in testnet-in-a-box mode, we allow connections to nodes with 0 non-genesis blocks.
  - getInterval
```
public int getInterval()
```
    How many blocks pass between difficulty adjustment periods. Bitcoin standardises this to be 2016.
  - getMaxTarget
```
public java.math.BigInteger getMaxTarget()
```
    Maximum target represents the easiest allowable proof of work.
  - getAlertSigningKey
```
public byte[] getAlertSigningKey()
```
    The key used to sign AlertMessages. You can use ECKey.verify(byte[], byte[], byte[]) to verify signatures using it.
  - getBip32HeaderP2PKHpub
```
public int getBip32HeaderP2PKHpub()
```
    Returns the 4 byte header for BIP32 wallet P2PKH - public key part.
  - getBip32HeaderP2PKHpriv
```
public int getBip32HeaderP2PKHpriv()
```
    Returns the 4 byte header for BIP32 wallet P2PKH - private key part.
  - getBip32HeaderP2WPKHpub
```
public int getBip32HeaderP2WPKHpub()
```
    Returns the 4 byte header for BIP32 wallet P2WPKH - public key part.
  - getBip32HeaderP2WPKHpriv
```
public int getBip32HeaderP2WPKHpriv()
```
    Returns the 4 byte header for BIP32 wallet P2WPKH - private key part.
  - getMaxMoney
```
public abstract Coin getMaxMoney()
```
    Returns the number of coins that will be produced in total, on this network. Where not applicable, a very large number of coins is returned instead (i.e. the main coin issue for Dogecoin).
  - getMinNonDustOutput
```
public abstract Coin getMinNonDustOutput()
```
    Any standard (ie P2PKH) output smaller than this value will most likely be rejected by the network.
  - getMonetaryFormat
```
public abstract MonetaryFormat getMonetaryFormat()
```
    The monetary object for this currency.
  - getUriScheme
```
public abstract java.lang.String getUriScheme()
```
    Scheme part for URIs, for example "bitcoin".
  - hasMaxMoney
```
public abstract boolean hasMaxMoney()
```
    Returns whether this network has a maximum number of coins (finite supply) or not. Always returns true for Bitcoin, but exists to be overridden for other networks.
  - getDefaultSerializer
```
public final MessageSerializer getDefaultSerializer()
```
    Return the default serializer for this network. This is a shared serializer.
    
    Returns:
    
    the default serializer for this network.
  - getSerializer
```
public abstract BitcoinSerializer getSerializer(boolean parseRetain)
```
    Construct and return a custom serializer.
  - getMajorityEnforceBlockUpgrade
```
public int getMajorityEnforceBlockUpgrade()
```
    The number of blocks in the last getMajorityWindow() blocks at which to trigger a notice to the user to upgrade their client, where the client does not understand those blocks.
  - getMajorityRejectBlockOutdated
```
public int getMajorityRejectBlockOutdated()
```
    The number of blocks in the last getMajorityWindow() blocks at which to enforce the requirement that all new blocks are of the newer type (i.e. outdated blocks are rejected).
  - getMajorityWindow
```
public int getMajorityWindow()
```
    The sampling window from which the version numbers of blocks are taken in order to determine if a new block version is now the majority.
  - getBlockVerificationFlags
```
public java.util.EnumSet<Block.VerifyFlag> getBlockVerificationFlags(Block block,
                                                                     VersionTally tally,
                                                                     java.lang.Integer height)
```
    The flags indicating which block validation tests should be applied to the given block. Enables support for alternative blockchains which enable tests based on different criteria.
    
    Parameters:
    
    block - block to determine flags for.
    
    height - height of the block, if known, null otherwise. Returned tests should be a safe subset if block height is unknown.
  - getTransactionVerificationFlags
```
public java.util.EnumSet<Script.VerifyFlag> getTransactionVerificationFlags(Block block,
                                                                            Transaction transaction,
                                                                            VersionTally tally,
                                                                            java.lang.Integer height)
```
    The flags indicating which script validation tests should be applied to the given transaction. Enables support for alternative blockchains which enable tests based on different criteria.
    
    Parameters:
    
    block - block the transaction belongs to.
    
    transaction - to determine flags for.
    
    height - height of the block, if known, null otherwise. Returned tests should be a safe subset if block height is unknown.
  - getProtocolVersionNum
```
public abstract int getProtocolVersionNum(NetworkParameters.ProtocolVersion version)
```

Class NetworkParameters

Nested Class Summary

Field Summary

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

SATOSHI_KEY

ID_MAINNET

ID_TESTNET

ID_REGTEST

ID_UNITTESTNET

PAYMENT_PROTOCOL_ID_MAINNET

PAYMENT_PROTOCOL_ID_TESTNET

PAYMENT_PROTOCOL_ID_UNIT_TESTS

PAYMENT_PROTOCOL_ID_REGTEST

genesisBlock

maxTarget

port

packetMagic

addressHeader

p2shHeader

dumpedPrivateKeyHeader

segwitAddressHrp

interval

targetTimespan

alertSigningKey

bip32HeaderP2PKHpub

bip32HeaderP2PKHpriv

bip32HeaderP2WPKHpub

bip32HeaderP2WPKHpriv

majorityEnforceBlockUpgrade

majorityRejectBlockOutdated

majorityWindow

id

spendableCoinbaseDepth

subsidyDecreaseBlockCount

dnsSeeds

addrSeeds

httpSeeds

checkpoints

defaultSerializer

TARGET_TIMESPAN

TARGET_SPACING

INTERVAL

BIP16_ENFORCE_TIME

MAX_COINS

MAX_MONEY

Constructor Detail

NetworkParameters

Method Detail

getId

getPaymentProtocolId

equals

hashCode

fromID

fromPmtProtocolID

getSpendableCoinbaseDepth

checkDifficultyTransitions

passesCheckpoint

isCheckpoint

getSubsidyDecreaseBlockCount

getDnsSeeds

getAddrSeeds

getHttpSeeds

getGenesisBlock

getPort

getPacketMagic

getAddressHeader

getP2SHHeader

getDumpedPrivateKeyHeader

getSegwitAddressHrp

getTargetTimespan

allowEmptyPeerChain

getInterval

getMaxTarget

getAlertSigningKey

getBip32HeaderP2PKHpub

getBip32HeaderP2PKHpriv

getBip32HeaderP2WPKHpub