Java

About

Our Java SDK, blockfrost-java is tested to work with JDK 18.

Build

$> git clone https://github.com/blockfrost/blockfrost-java.git
$> ./gradlew clean build

Publish to Local Maven Repository

$> ./gradlew publishToMavenLocal

Run Integration tests

To run integration tests, you need Blockfrost Project Id for Cardano Testnet.

export BF_PROJECT_ID=<Blockfrost Cardano Testnet Project Id>
export BF_IPFS_PROJECT_ID=<Blockfrost Ipfs Project Id>

./gradlew integrationTest -PBF_PROJECT_ID=${BF_PROJECT_ID} -PBF_IPFS_PROJECT_ID=${BF_IPFS_PROJECT_ID}

How to use ?

Add dependency

• For Maven, add the following dependency to project's pom.xml

    <dependencies>
        <dependency>
            <groupId>io.blockfrost</groupId>
            <artifactId>blockfrost-java</artifactId>
            <version>$version</version>
        </dependency>
    </dependencies>

• For Gradle, add the following dependency to build.gradle

compile 'com.bloxbean.cardano:cardano-client-lib:$version'

Note: Replace '$version' with the correct version number

For example: $version = 0.1.0-SNAPSHOT (If you have published snapshot jar to your local maven repository)

Usage

Following services are available

• Cardano
  • AccountService
  • AddressService
  • AssetService
  • BlockService
  • EpochService
  • HealthService
  • LedgerService
  • MetadataService
  • NetworkService
  • PoolService
  • TransactionService
  • NutLinkService
• IPFS
  • IPFSService

Cardano Api Usage

• Create a BlockService instance

BlockService blockService = new BlockServiceImpl(Constants.BLOCKFROST_TESTNET_URL, PROJECT_ID);

• Get Latest Block Details

Block block = blockService.getLatestBlock();

IPFS Api Usage

• Create IPFSService instance

IPFSService ipfsService = new IPFSServiceImpl(Constants.BLOCKFROST_IPFS_URL, IPFS_PROJECT_ID);

• Add to IPFS, Pin the content and Get content by CID

File file = new File(<path to file>);
IPFSObject ipfsObject = ipfsService.add(file);

//pin
PinResponse pinResponse = ipfsService.pinAdd(ipfsObject.getIpfsHash());

//get
byte[] bytes = ipfsService.get(ipfsObject.getIpfsHash());

Release resources when program exits

To release OkHttpClient's thread pool and other resources when the program exits, invoke the following api.

NetworkHelper.getInstance().shutdown();

Configuration

A supported configuration property can be set through system property or environment variable. You can also directly set a config property using ConfigHelper.

Example:

ConfigHelper.INSTANCE.setThreadCount(60);
ConfigHelper.INSTANCE.setRateLimitForPeriod(40);

List of supported config properties

Property Name	Description
BF_API_MAX_THREADS	No of threads to use while fetching multiple pages of data in a single request. Default Value: 10 (Example: getAllAddressUtxos, getAddressTransactions ...)
BF_RATE_LIMIT_FOR_PERIOD	The permission limit for refresh period. This property is used in rate limit implementation. Default Value: 10
BF_RATE_LIMIT_REFRESH_PERIOD_IN_SEC	The period of limit refresh in sec. Default Value: 1 After each period rate limiter sets its permission count to value set for BF_RATE_LIMIT_FOR_PERIOD.
BF_RATE_LIMIT_TIMEOUT_DURATION_IN_MILLIS	The default wait for permission duration in milliseconds. Default Value: 5000
BF_CONNECTION_TIMEOUT	The connect timeout (connection/read/write) for new connections in seconds. Default Value: 90