= PolkaJ - Polkadot Java Client :lib-version: 0.3.0 :lib-version-dev: 0.5.0-SNAPSHOT

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Java client library to use and access API of Polkadot based networks.

WARNING: UNDER DEVELOPMENT

• Latest Stable Version: {lib-version}
• Latest Snapshot Version: {lib-version-dev}

== Modules

• io.emeraldpay.polkaj:polkaj-scale:{lib-version} - SCALE codec implementation
• io.emeraldpay.polkaj:polkaj-scale-types:{lib-version} - SCALE mapping for standard Polkadot types
• io.emeraldpay.polkaj:polkaj-schnorrkel:{lib-version} - Schnorrkel for Java
• io.emeraldpay.polkaj:polkaj-ss58:{lib-version} - SS58 codec to encode/decode addresses and pubkeys
• io.emeraldpay.polkaj:polkaj-common-types:{lib-version} - common types (Address, DotAmount, Hash256, etc)
• io.emeraldpay.polkaj:polkaj-json-types:{lib-version} - JSON RPC mapping to Java classes
• io.emeraldpay.polkaj:polkaj-api-base:{lib-version} - RPC base classes
• io.emeraldpay.polkaj:polkaj-api-http:{lib-version} - JSON RPC HTTP client
• io.emeraldpay.polkaj:polkaj-api-ws:{lib-version} - JSON RPC WebSocket client
• io.emeraldpay.polkaj:polkaj-tx:{lib-version} - Storage access and Extrinsics

== Usage

To use development SNAPSHOT versions you need to install the library into the local Maven repository.

.Install into local Maven

gradle install

.Using with Gradle [source,groovy,subs="attributes"]

repositories { // polkaj public repo maven { url "https://dl.bintray.com/emerald/polkaj" } // required for com.github.multiformats:java-multibase library maven { url 'https://jitpack.io' } }

dependencies { implementation 'io.emeraldpay.polkaj:polkaj-api-http:{lib-version}' }

== Documentation

See link:docs/[Documentation] in ./docs directory, and a demonstration in ./examples.

== Example

.Show current finalized block [source,java]

PolkadotHttpApi client = PolkadotApi.newBuilder() .rpcCallAdapter(JavaHttpAdapter.newBuilder().build()) .build(); Future hashFuture = client.execute( PolkadotApi.commands().getFinalizedHead() );

Hash256 hash = hashFuture.get(); System.out.println("Current head: " + hash);

Future blockFuture = client.execute( PolkadotApi.commands().getBlock(hash) );

BlockResponseJson block = blockFuture.get(); System.out.println("Current height: " + block.getBlock().getHeader().getNumber()); System.out.println("State hash: " + block.getBlock().getHeader().getStateRoot());

client.close();

== License

The core project code is released under Apache 2.0 license.

Examples and docs are published under CC0 license + additionally Apache 2.0 for code parts in the examples.