web3j 2.0An update

@conors10

Transaction Managers

Choose how you transact with Ethereum blockchains

• Offline signing (web3j)

• Online signing (Ethereum client)

• What about other clients, e.g. Quorum?

Transaction ManagersOptional EIP-155 (Replay attack) support

Use a full client

Use Quorum

Use web3j (default)

Event filtersWorking with filters shouldn’t be hard

Geth/Parity:

1. Create filter

2. Poll for changes

3. Terminate filter

web3j:

• Simple (one line of code)

• Reactive (ReactiveX Observables)

Reactive, typed events

Create an Observable stream

Solidity

Java

Homebrew + build info$ brew tap web3j/web3j $ brew install web3j $ web3j version

_ _____ _ _ | | |____ (_) (_) __ _____| |__ / /_ _ ___ \ \ /\ / / _ \ '_ \ \ \ | | | / _ \ \ V V / __/ |_) |.___/ / | _ | || (_) | \_/\_/ \___|_.__/ \____/| |(_)|_| \___/ _/ | |__/

Version: 2.0.1 Build timestamp: 2017-02-21 06:19:33.654 UTC

web3j + Spring

Spring Boot integration

• web3j-spring-boot-starter

Other stuffLight wallet generation

• ~50msec light

• ~700 msec full

Fast IPC client connections

• Named pipe (Windows)

• Domain socket (OS X/Linux)

Default types

• Empty types for smart contract params - e.g. Uint256.DEFAULT

https://web3j.io