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
• Account hooks
• Lambda SStore

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
• Contract hooks

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.org.hiero=trace.

For hook-related examples (like AddHooksToAccountExample), you also need to set the HOOK_CONTRACT_ID variable:

• In our examples we use a bytecote from a specific smart contract which can be found in /contracts/HieroHookContract.sol.
• Note: Hook functionality may not be available on all networks. The example will demonstrate the configuration even if hooks are not supported.

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.