macrotea/ethereum-api

Ethereum RPC java client

ethereum-api

Java client of JSON RPC Ethereum API, based on reference.

Prerequisities

• java 8
• maven 3.x
• a local/remote ethereum blockchain based on https://github.com/ethereum/wiki/wiki/JSON-RPC reference.

Configuration

change the ethereum blockchain address in yope-ethereum-rest\application.yml

org.ethereum.address: http:/...

How to build and run it

cd yope-ethereum-rest

mvn spring-boot:run

RESTful APIs

Account balance:

Returns the balance of the account (in szabo) of given address.

Path

GET /accounts/${accountAddress}/balance

Parameters

• accountAddress: address of the account

curl -X GET -H "Content-Type: application/json" "http://localhost:8080/accounts/0x03733b713032e9040d04acd4720bedaa717378df/balance"

{"response":825000000,"responseCode":200,"message":"OK"}%  

Contract creation:

Creates a contract into the blockchain:

Path

POST /contracts

Parameters

• solidityContract: content of the Solidity Contract
• accountAddress: address of the account

curl -X POST -H "Content-Type: application/json"  -d '{
    "solidityContract": "contract SimpleStorage { uint storedData; function set(uint x) { storedData = x; } function get() constant returns (uint retVal) { return storedData; } }",
    "accountAddress": "0x03733b713032e9040d04acd4720bedaa717378df"
}' "http://localhost:8080/contracts"

{
  "response": {
    "SimpleStorage": {
      "transactionHash": "0x87aad9043516c0c5192515eb7ec5d62619f73fec6e666b367a8796c5d7e587d4",
      "contractAddress": "0x8f7de5360431abfd5422aac1888c1e9902e6b543",
      "blockHash": "0x748a4654727b8edc0410735b866c928e20600efbd99107307348e851757dd81e",
      "transactionIndex": 0,
      "blockNumber": 165,
      "cumulativeGasUsed": 37558,
      "gasUsed": 37558
    }
  },
  "responseCode": 200,
  "message": "OK"
}

Contract update:

Modifies the state of a contract

Path

PUT /contracts/${contractAddress}

Parameters

• solidityContract: content of the Solidity Contract
• accountAddress: address of the account
• contractKey: Solidity contract name
• method: method to modify
• args: array of method's input parameters

curl -X PUT -H "Content-Type: application/json" -H "Cache-Control: no-cache" -H "Postman-Token: 90518cc7-f2ef-345b-c1a3-c7e5f022aa3b" -d '{
    "solidityContract": "contract SimpleStorage { uint storedData; function set(uint x) { storedData = x; } function get() constant returns (uint retVal) { return storedData; } }",
    "accountAddress": "0x03733b713032e9040d04acd4720bedaa717378df",
    "contractKey": "SimpleStorage",
    "method": "set",
    "args": ["53"]
}' "http://localhost:8080/contracts/0xfdd64188d6134f955dda2bd55234acefa2779da6"

Contract run:

Executes a contract

Path

POST /contracts/${contractAddress}

Parameters

• solidityContract: content of the Solidity Contract
• accountAddress: address of the account
• contractKey: Solidity contract name
• method: method to execute

curl -X POST -H "Content-Type: application/json" -H "Cache-Control: no-cache" -H "Postman-Token: 0b8745d2-ebaa-cd6c-da82-4f075c47e5bb" -d '{
    "solidityContract": "contract SimpleStorage { uint storedData; function set(uint x) { storedData = x; } function get() constant returns (uint retVal) { return storedData; } }",
    "accountAddress": "0x03733b713032e9040d04acd4720bedaa717378df",
    "contractKey": "SimpleStorage",
    "method": "get"
}' "http://localhost:8080/contracts/0xfdd64188d6134f955dda2bd55234acefa2779da6"

License

The ethereum-api is released under the MIT permissive free software license.