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web3j-quorum: Java integration library for Quorum

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web3j-quorum is an extension to web3j <https://github.com/web3j/web3j>_ providing support for JP Morgan's Quorum <https://github.com/jpmorganchase/quorum>_ API.

web3j is a lightweight, reactive, type safe Java library for integrating with clients (nodes) on distributed ledger or blockchain networks.

For further information on web3j, please refer to the main project page <https://github.com/web3j/web3j>_ and the documentation at Read the Docs <http://docs.web3j.io>_.

Features

• Support for Quorum's private transactions through private transaction manager
• Ability to send signed private transactions
• Works out the box with web3j's smart contract wrappers <https://docs.web3j.io/smart_contracts/#solidity-smart-contract-wrappers>_

Getting started

Add the relevant dependency to your project:

Maven

Java 17:

.. code-block:: xml

Gradle

Java 17:

.. code-block:: groovy

compile ('org.web3j:quorum:4.10.0')

Run Quorum

See instructions as per the Quorum project page <https://github.com/jpmorganchase/quorum>_

Start sending requests

To send synchronous requests:

.. code-block:: java

Quorum quorum = Quorum.build(new HttpService("http://localhost:22001")); Web3ClientVersion web3ClientVersion = quorum.web3ClientVersion().send(); String clientVersion = web3ClientVersion.getWeb3ClientVersion();

To send asynchronous requests:

.. code-block:: java

Quorum quorum = Quorum.build(new HttpService("http://localhost:22001")); Web3ClientVersion web3ClientVersion = quorum.web3ClientVersion().sendAsync().get(); String clientVersion = web3ClientVersion.getWeb3ClientVersion();

To use an RxJava Observable:

.. code-block:: java

Quorum quorum = Quorum.build(new HttpService("http://localhost:22001")); quorum.web3ClientVersion().observable().subscribe(x -> { String clientVersion = x.getWeb3ClientVersion(); ... });

IPC

web3j also supports fast inter-process communication (IPC) via file sockets to clients running on the same host as web3j. To connect simply use UnixIpcService or WindowsIpcService instead of HttpService when you create your service:

.. code-block:: java

// OS X/Linux/Unix: Quorum quorum = Quorum.build(new UnixIpcService("/path/to/socketfile")); ...

// Windows Quorum quorum = Quorum.build(new WindowsIpcService("/path/to/namedpipefile")); ...

Smart Contract Wrappers

Smart contract wrappers <https://docs.web3j.io/smart_contracts/#solidity-smart-contract-wrappers>_ generated using web3j 2.0+ work out the box with with web3j-quorum.

The only difference is that you'll need to use the Quorum ClientTransactionManager <https://github.com/web3j/quorum/tree/master/src/main/java/org/web3j/quorum/tx/ClientTransactionManager.java>_:

.. code-block:: java

QuorumTransactionManager transactionManager = new QuorumTransactionManager( web3j, "0x", Arrays.asList("<privateFor-public-key>", ...); YourSmartContract contract = YourSmartContract.deploy( , <transactionManager>, GAS_PRICE, GAS_LIMIT, , ..., <paramN>).send();

These wrappers are similar to the web3j smart contract wrappers with the exception that the transactions are signed by the Quorum nodes rather then by web3j. They also support the privateFor field on transactions.

See the web3j documentation <https://docs.web3j.io/smart_contracts/>_ for a detailed overview of smart contracts and web3j.

Sending Raw Private Transactions

web3j supports sending raw private transactions through a connection to Quorum Transaction Managers. Code examples

Connection to Tessera via HTTP

.. code-block:: java

   Credentials credentials = ...
   //connect to quorum node via http or ipc as described above
   Quorum quorum = ... 

   EnclaveService enclaveService = new EnclaveService("http://TESSERA_THIRD_PARTY_URL", TESSERA_THIRD_PARTY_PORT, httpClient);
   Enclave enclave = new Tessera(enclaveService, quorum);

   QuorumTransactionManager qrtxm = new QuorumTransactionManager(
       quorum, credentials, TM_FROM_KEY, Arrays.asList(TM_TO_KEY_ARRAY),
       enclave,
       30,     // Retry times
       2000);  // Sleep

Connection to Tessera via IPC
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

.. code-block:: java

   Credentials credentials = ...
   //connect to quorum node via http or ipc as described above
   Quorum quorum = ... 
   
   //build http client that supports ipc connection
   UnixDomainSocketFactory socketFactory = new UnixDomainSocketFactory(new File("TESSERA_IPC_PATH"));
        OkHttpClient client = new OkHttpClient.Builder()
                .socketFactory(socketFactory)
                .build();

   EnclaveService enclaveService = new EnclaveService("http://localhost", TESSERA_THIRD_PARTY_PORT, client);
   Enclave enclave = new Tessera(enclaveService, quorum);

   QuorumTransactionManager qrtxm = new QuorumTransactionManager(
       quorum, credentials, TM_FROM_KEY, Arrays.asList(TM_TO_KEY_ARRAY),
       enclave,
       30,     // Retry times
       2000);  // Sleep
       
Connection to Constellation via IPC

.. code-block:: java

Credentials credentials = ... //connect to quorum node via http or ipc as described above Quorum quorum = ...

//build http client that supports ipc connection UnixDomainSocketFactory socketFactory = new UnixDomainSocketFactory(new File("CONSTELLATION_IPC_PATH")); OkHttpClient client = new OkHttpClient.Builder() .socketFactory(socketFactory) .build();

EnclaveService enclaveService = new EnclaveService("http://localhost", CONSTELLATION_THIRD_PARTY_PORT, client); Enclave enclave = new Constellation(enclaveService, quorum);

QuorumTransactionManager qrtxm = new QuorumTransactionManager( quorum, credentials, TM_FROM_KEY, Arrays.asList(TM_TO_KEY_ARRAY), enclave, 30, // Retry times 2000); // Sleep

Using the QuorumTransactionManager with Smart Contract Wrappers

.. code-block:: java

   YourSmartContract.deploy(quorum,
       qrtxm,
       GAS_PRICE, GAS_LIMIT,
       <param1>, ..., <paramN>).send();
       
       
       
Using the QuorumTransactionManager alone
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Using a single QuorumTransactionManager method ``signAndSend``
	
.. code-block:: java
	
	RawTransaction rawTransaction = ...
	EthSendTransaction ethSendTransaction = qrtxm.signAndSend(rawTransaction);
	
Using multiple exposed QuorumTransactionManager methods (``storeRawRequest, sign, sendRaw``)

.. code-block:: java

	//send raw bytecode to QuorumTranasctionManager
	SendResponse storeRawResponse = qrtxm.storeRawRequest(HEX_ENCODED_SMARTCONTRACT_BYTECODE, TM_FROM_KEY, Arrays.asList(TM_TO_KEY_ARRAY));
	String tesseraTxHash = Numeric.toHexString(Base64.getDecoder().decode(storeRawResponse.getKey()));
	
	//create raw transaction with hash returned from QuorumTransactionManager
	RawTransaction rawTransaction = ...
	
	//sign raw transaction
	String signedTx = qrtxm.sign(rawTransaction);
	
	//send signed raw transaction to quorum node
	EthSendTransaction ethSendTransaction = qrtxm.sendRaw(signedTx, Arrays.asList(TM_TO_KEY_ARRAY));
	
Retrieving a private transaction payload with Enclave ``receive`` method

.. code-block:: java

	String payload = enclave.receiveRequest(tesseraTxHash, TM_TO_KEY);
	
Full sample code
~~~~~~~~~~~~~~~~

`Sample code <https://github.com/jpmorganchase/quorum-examples/tree/master/examples/7nodes/samples/send-private-txn-java>`_ for sending raw private transactions via smart contract, QuorumTransactionManager and Enclave


Using web3j RawTransactionManager
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

.. code-block:: java

   // Raw txn
   RawTransactionManager qrtxm = new RawTransactionManager(
         quorum,
         credentials,
         30,     // Retry times
         2000);  // Sleep

   YourSmartContract.deploy(quorum,
         qrtxm,
         GAS_PRICE, GAS_LIMIT,
         <param1>, ..., <paramN>).send();