web3j Spring Boot Starter

Integrate web3j into your Spring Boot applications via Spring's dependency injection.

Getting started

A sample application is available here

To use, create a new Spring Boot Application, and include the following dependencies:

Maven:

<dependency>
    <groupId>org.web3j</groupId>
    <artifactId>web3j-spring-boot-starter</artifactId>
    <version>4.0.3</version>
</dependency>

Gradle:

compile ('org.web3j:web3j-spring-boot-starter:4.0.3')

Now Spring can inject web3j instances for you where ever you need them:

@Autowired
private Web3j web3j;

No additional configuration is required if you want to connect via HTTP to the default URL http://localhost:8545.

Otherwise simply add the address of the endpoint in your application properties:

# An infura endpoint
web3j.client-address = https://rinkeby.infura.io/

# Or, an IPC endpoing
web3j.client-address = /path/to/file.ipc

Admin clients

If you wish to make use of the personal module methods that are common to both Parity and Geth
to manage accounts, enable the admin client:

web3j.admin-client = true

Then Spring can inject admin clients:

@Autowired
private Admin admin;

HTTP client configuration

Some Ethereum operations take longer than the default HTTP timeout set by the OkHttp3 library used by web3j. To configure those timeouts set the web3j httpTimeoutSeconds property:

web3j.httpTimeoutSeconds = 600  

This sets all three OkHttp3 timeouts: connect, read, and write.

Valid values are any non-negative integer.

A value of '0' means: no timeout.

Note: This is not required for transacting with web3j.

Further information

For further information on web3j, please refer to the web3j home page.