Chapter 367. Web3j Ethereum Blockchain Component Available as of Camel version 2.22 The Ethereum blockchain component uses the web3j client API and allows you to interact with Ethereum compatible nodes such as Geth , Parity , Quorum , Infura , etc. Maven users will need to add the following dependency to their pom.xml for this component: <dependency> <groupId>org.apache.camel</groupId> <artifactId>camel-web3j</artifactId> <version>x.x.x</version> <!-- use the same version as your Camel core version --> </dependency> 367.1. URI Format web3j://<local/remote host:port or local IPC path>[?options] 367.2. Web3j Options The Web3j Ethereum Blockchain component supports 2 options, which are listed below. Name Description Default Type configuration (common) Default configuration Web3jConfiguration resolveProperty Placeholders (advanced) Whether the component should resolve property placeholders on itself when starting. Only properties which are of String type can use property placeholders. true boolean The Web3j Ethereum Blockchain endpoint is configured using URI syntax: with the following path and query parameters: 367.2.1. Path Parameters (1 parameters): Name Description Default Type nodeAddress Required Sets the node address used to communicate String 367.2.2. Query Parameters (38 parameters): Name Description Default Type addresses (common) Contract address or a list of addresses. List fromAddress (common) The address the transaction is send from String fromBlock (common) The block number, or the string latest for the last mined block or pending, earliest for not yet mined transactions. latest DefaultBlockParameter fullTransactionObjects (common) If true it returns the full transaction objects, if false only the hashes of the transactions. false boolean gasLimit (common) The maximum gas allowed in this block. BigInteger privateFor (common) A transaction privateFor nodes with public keys in a Quorum network List quorumAPI (common) If true, this will support Quorum API. false boolean toAddress (common) The address the transaction is directed to. String toBlock (common) The block number, or the string latest for the last mined block or pending, earliest for not yet mined transactions. latest DefaultBlockParameter topics (common) Topics are order-dependent. Each topic can also be a list of topics. Specify multiple topics separated by comma. String web3j (common) The preconfigured Web3j object. Web3j bridgeErrorHandler (consumer) Allows for bridging the consumer to the Camel routing Error Handler, which mean any exceptions occurred while the consumer is trying to pickup incoming messages, or the likes, will now be processed as a message and handled by the routing Error Handler. By default the consumer will use the org.apache.camel.spi.ExceptionHandler to deal with exceptions, that will be logged at WARN or ERROR level and ignored. false boolean exceptionHandler (consumer) To let the consumer use a custom ExceptionHandler. Notice if the option bridgeErrorHandler is enabled then this option is not in use. By default the consumer will deal with exceptions, that will be logged at WARN or ERROR level and ignored. ExceptionHandler exchangePattern (consumer) Sets the exchange pattern when the consumer creates an exchange. ExchangePattern address (producer) Contract address. String atBlock (producer) The block number, or the string latest for the last mined block or pending, earliest for not yet mined transactions. latest DefaultBlockParameter blockHash (producer) Hash of the block where this transaction was in. String clientId (producer) A random hexadecimal(32 bytes) ID identifying the client. String data (producer) The compiled code of a contract OR the hash of the invoked method signature and encoded parameters. String databaseName (producer) The local database name. String filterId (producer) The filter id to use. BigInteger gasPrice (producer) Gas price used for each paid gas. BigInteger hashrate (producer) A hexadecimal string representation (32 bytes) of the hash rate. String headerPowHash (producer) The header's pow-hash (256 bits) used for submitting a proof-of-work solution. String index (producer) The transactions/uncle index position in the block. BigInteger keyName (producer) The key name in the database. String mixDigest (producer) The mix digest (256 bits) used for submitting a proof-of-work solution. String nonce (producer) The nonce found (64 bits) used for submitting a proof-of-work solution. String operation (producer) Operation to use. transaction String position (producer) The transaction index position withing a block. BigInteger priority (producer) The priority of a whisper message. BigInteger sha3HashOfDataToSign (producer) Message to sign by calculating an Ethereum specific signature. String signedTransactionData (producer) The signed transaction data for a new message call transaction or a contract creation for signed transactions. String sourceCode (producer) The source code to compile. String transactionHash (producer) The information about a transaction requested by transaction hash. String ttl (producer) The time to live in seconds of a whisper message. BigInteger value (producer) The value sent within a transaction. BigInteger synchronous (advanced) Sets whether synchronous processing should be strictly used, or Camel is allowed to use asynchronous processing (if supported). false boolean 367.3. Spring Boot Auto-Configuration The component supports 33 options, which are listed below. Name Description Default Type camel.component.web3j.configuration.address Contract address. String camel.component.web3j.configuration.addresses Contract address or a list of addresses. List camel.component.web3j.configuration.block-hash Hash of the block where this transaction was in. String camel.component.web3j.configuration.client-id A random hexadecimal(32 bytes) ID identifying the client. String camel.component.web3j.configuration.data The compiled code of a contract OR the hash of the invoked method signature and encoded parameters. String camel.component.web3j.configuration.database-name The local database name. String camel.component.web3j.configuration.filter-id The filter id to use. BigInteger camel.component.web3j.configuration.from-address The address the transaction is send from String camel.component.web3j.configuration.full-transaction-objects If true it returns the full transaction objects, if false only the hashes of the transactions. false Boolean camel.component.web3j.configuration.gas-limit The maximum gas allowed in this block. BigInteger camel.component.web3j.configuration.gas-price Gas price used for each paid gas. BigInteger camel.component.web3j.configuration.hashrate A hexadecimal string representation (32 bytes) of the hash rate. String camel.component.web3j.configuration.header-pow-hash The header's pow-hash (256 bits) used for submitting a proof-of-work solution. String camel.component.web3j.configuration.index The transactions/uncle index position in the block. BigInteger camel.component.web3j.configuration.key-name The key name in the database. String camel.component.web3j.configuration.mix-digest The mix digest (256 bits) used for submitting a proof-of-work solution. String camel.component.web3j.configuration.nonce The nonce found (64 bits) used for submitting a proof-of-work solution. String camel.component.web3j.configuration.operation Operation to use. transaction String camel.component.web3j.configuration.position The transaction index position withing a block. BigInteger camel.component.web3j.configuration.priority The priority of a whisper message. BigInteger camel.component.web3j.configuration.private-for A transaction privateFor nodes with public keys in a Quorum network List camel.component.web3j.configuration.quorum-a-p-i If true, this will support Quorum API. false Boolean camel.component.web3j.configuration.sha3-hash-of-data-to-sign Message to sign by calculating an Ethereum specific signature. String camel.component.web3j.configuration.signed-transaction-data The signed transaction data for a new message call transaction or a contract creation for signed transactions. String camel.component.web3j.configuration.source-code The source code to compile. String camel.component.web3j.configuration.to-address The address the transaction is directed to. String camel.component.web3j.configuration.topics Topics are order-dependent. Each topic can also be a list of topics. Specify multiple topics separated by comma. List camel.component.web3j.configuration.transaction-hash The information about a transaction requested by transaction hash. String camel.component.web3j.configuration.ttl The time to live in seconds of a whisper message. BigInteger camel.component.web3j.configuration.value The value sent within a transaction. BigInteger camel.component.web3j.configuration.web3j The preconfigured Web3j object. Web3j camel.component.web3j.enabled Enable web3j component true Boolean camel.component.web3j.resolve-property-placeholders Whether the component should resolve property placeholders on itself when starting. Only properties which are of String type can use property placeholders. true Boolean You can append query options to the URI in the following format, ?options=value&option2=value&... 367.4. Message Headers Header Description All URI options All URI options can also be set as exchange headers. 367.5. Samples Listen for new mined blocks and send the block hash to a jms queue: from("web3j://http://127.0.0.1:7545?operation=ETH_BLOCK_HASH_OBSERVABLE") .to("jms:queue:blocks"); Use the block hash code to retrieve the block and full transaction details: from("jms:queue:blocks") .setHeader(BLOCK_HASH, body()) .to("web3j://http://127.0.0.1:7545?operation=ETH_GET_BLOCK_BY_HASH&fullTransactionObjects=true"); Read the balance of an address at a specific block number: from("direct:start") .to("web3j://http://127.0.0.1:7545?operation=ETH_GET_BALANCE&address=0xc8CDceCE5d006dAB638029EBCf6Dd666efF5A952&atBlock=10");

Commands:
<dependency> <groupId>org.apache.camel</groupId> <artifactId>camel-web3j</artifactId> <version>x.x.x</version> <!-- use the same version as your Camel core version --> </dependency>
web3j://<local/remote host:port or local IPC path>[?options]
web3j:nodeAddress
from("web3j://http://127.0.0.1:7545?operation=ETH_BLOCK_HASH_OBSERVABLE") .to("jms:queue:blocks");
from("jms:queue:blocks") .setHeader(BLOCK_HASH, body()) .to("web3j://http://127.0.0.1:7545?operation=ETH_GET_BLOCK_BY_HASH&fullTransactionObjects=true");
from("direct:start") .to("web3j://http://127.0.0.1:7545?operation=ETH_GET_BALANCE&address=0xc8CDceCE5d006dAB638029EBCf6Dd666efF5A952&atBlock=10");