README.md

Java examples

SDK

• Construct a client
• Generate a key
• Generate a key (with mnemonic)
• Get address book
• Get exchange rates
• Logger

Transactions

• Sign a transaction
• Transaction serialization (HIP-745)

Schedule Transaction

• Sign a scheduled transfer transaction
• Sign a scheduled transfer transaction (with comments)
• Schedule identical transaction
• Schedule multisig transaction
• Schedule multisig transaction (with threshold)

Accounts and HBAR

• Create an account
• Create an account (threshold key)
• Create an account (with alias)
• Create an account (with alias and receiver signature required)
• Account creation ways
• Create an account with Hts
• Auto create an account with transfer transaction
• Account alias
• Account allowance
• Get account info
• Get account balance
• Update an account
• Delete an account
• Staking
• Staking (with update)
• Multisig

Consensus Service

• Create a topic
• Topic management
• Consensus Pub Sub
• Consensus Pub Sub (chunked)
• Consensus Pub Sub (with submit key)

Token Service

• Transfer Hbar
• Transfer Hbar (multi app)
• Transfer tokens
• Transfer using EVM address
• Custom fees
• Custom fees (exempt)
• NFT Allowances
• Zero token operations
• Change Or Remove Existing Keys From A Token (HIP-540)
• Reject A Token (HIP-904)

File Service

• Create a file
• File append (chunked)
• Get file contents
• Delete a file

Smart Contract Service

• Create a contract
• Create a stateful contract
• Contract nonce (HIP-729)
• Interaction with a contract

Miscellaneous

• Checksum validation
• Pseudorandom Number Generator

Usage

Configuration

Running the examples requires .env file to exist in the examples folder if running with Gradle:

cp .env.sample .env

And in the root project folder if running with Intellij IDEA:

cp .env.sample ../.env

The OPERATOR_ID and OPERATOR_KEY variables should be set in a .env file. Optionally, you can set the HEDERA_NETWORK and SDK_LOG_LEVEL variables:

• You can set the HEDERA_NETWORK to localhost, testnet, previewnet or mainnet for configuring the network. If the HEDERA_NETWORK is not set, it will default to testnet.
• You can set the SDK_LOG_LEVEL to TRACE, DEBUG, INFO, WARN, ERROR or SILENT for configuring the logging. If the SDK_LOG_LEVEL is not set, it will default to SILENT. Important pre-requisite to see logs: set simple logger log level to same level as the SDK_LOG_LEVEL, for example via VM options: -Dorg.slf4j.simpleLogger.log.com.hedera.hashgraph=trace.

Therefore, the format of the configuration file should be as follows:

OPERATOR_ID=0.0.102...
OPERATOR_KEY=0xeae...
# Optionally set HEDERA_NETWORK and SDK_LOG_LEVEL
HEDERA_NETWORK=previewnet
SDK_LOG_LEVEL=WARN

Running with Gradle

Note that the below ./gradlew commands should be run from the root of the project.

Template:

./gradlew -q :examples:run<NameOfExample>

Concrete example:

./gradlew -q :examples:runGenerateKey

Running with Intellij

Simply execute the main function of the desired example.