/* * Copyright 2011 Google Inc. * Copyright 2014 Andreas Schildbach * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ package org.bitcoinj.examples; import org.bitcoinj.core.*; import org.bitcoinj.params.TestNet3Params; import org.bitcoinj.store.BlockStore; import org.bitcoinj.store.MemoryBlockStore; import org.bitcoinj.utils.BriefLogFormatter; import java.net.InetAddress; import java.util.concurrent.Future; /** * Downloads the block given a block hash from the localhost node and prints it out. */ public class FetchBlock { public static void main(String[] args) throws Exception { BriefLogFormatter.init(); System.out.println("Connecting to node"); final NetworkParameters params = TestNet3Params.get(); BlockStore blockStore = new MemoryBlockStore(params); BlockChain chain = new BlockChain(params, blockStore); PeerGroup peerGroup = new PeerGroup(params, chain); peerGroup.start(); PeerAddress addr = new PeerAddress(InetAddress.getLocalHost(), params.getPort()); peerGroup.addAddress(addr); peerGroup.waitForPeers(1).get(); Peer peer = peerGroup.getConnectedPeers().get(0); Sha256Hash blockHash = Sha256Hash.wrap(args[0]); Future<Block> future = peer.getBlock(blockHash); System.out.println("Waiting for node to send us the requested block: " + blockHash); Block block = future.get(); System.out.println(block); peerGroup.stopAsync(); } }