現在、Hyperledger Fabricを掘っていますが、Java SDK(ここでは1.0.0-betaについて話しています)で作業を開始できません。Fabricへの接続から始まる実例はありますか?ノード、クエリの実行など?私がこれまでに広範なグーグル検索で見つけたのは、「レッツ・ライト・サム・チェーンコード」の例だけです。
以下をご覧ください
Fabcarの一部の機能を実装する例を次に示します(query.jsおよびinvoke.js-1台の車でのみ照会し、所有者を変更します)
WindowsでJava8を使用しました。別のOSを使用する場合は、それに応じてパスを更新してください。
追加のライブラリを避けるためにjsonの実装を使用しませんでした(証明書を少し処理する必要があります-以下を参照)。
Fabcarの例を起動して実行する必要があります。そして(「jsonなし」のため):
コード(fabrictest/fabcar/Program.Java):
package fabrictest.fabcar;
import Java.io.BufferedReader;
import Java.io.FileInputStream;
import Java.io.IOException;
import Java.io.InputStream;
import Java.io.InputStreamReader;
import Java.nio.file.Files;
import Java.nio.file.Path;
import Java.nio.file.Paths;
import Java.security.GeneralSecurityException;
import Java.security.KeyFactory;
import Java.security.PrivateKey;
import Java.security.spec.PKCS8EncodedKeySpec;
import Java.util.Collection;
import Java.util.Date;
import Java.util.HashSet;
import Java.util.Random;
import Java.util.Set;
import javax.xml.bind.DatatypeConverter;
import org.hyperledger.fabric.sdk.ChaincodeID;
import org.hyperledger.fabric.sdk.Channel;
import org.hyperledger.fabric.sdk.Enrollment;
import org.hyperledger.fabric.sdk.HFClient;
import org.hyperledger.fabric.sdk.ProposalResponse;
import org.hyperledger.fabric.sdk.QueryByChaincodeRequest;
import org.hyperledger.fabric.sdk.TransactionProposalRequest;
import org.hyperledger.fabric.sdk.User;
import org.hyperledger.fabric.sdk.security.CryptoSuite;
public class Program {
private static HFClient client = null;
public static void main(String[] args) throws Throwable {
/*
* wallet_path: path.join(__dirname, './creds'), user_id: 'PeerAdmin',
* channel_id: 'mychannel', chaincode_id: 'fabcar', network_url:
* 'grpc://192.168.99.100:7051', orderer: grpc://192.168.99.100:7050
*
*/
// just new objects, without any payload inside
client = HFClient.createNewInstance();
CryptoSuite cs = CryptoSuite.Factory.getCryptoSuite();
client.setCryptoSuite(cs);
// We implement User interface below in code
// folder c:\tmp\creds should contain PeerAdmin.cert (extracted from HF's fabcar
// example's PeerAdmin json file)
// and PeerAdmin.priv (copy from
// cd96d5260ad4757551ed4a5a991e62130f8008a0bf996e4e4b84cd097a747fec-priv)
User user = new SampleUser("c:\\tmp\\creds", "PeerAdmin");
// "Log in"
client.setUserContext(user);
// Instantiate channel
Channel channel = client.newChannel("mychannel");
channel.addPeer(client.newPeer("peer", "grpc://192.168.99.100:7051"));
// It always wants orderer, otherwise even query does not work
channel.addOrderer(client.newOrderer("orderer", "grpc://192.168.99.100:7050"));
channel.initialize();
// below is querying and setting new owner
String newOwner = "New Owner #" + new Random(new Date().getTime()).nextInt(999);
System.out.println("New owner is '" + newOwner + "'\n");
queryFabcar(channel, "CAR1");
updateCarOwner(channel, "CAR1", newOwner, false);
System.out.println("after request for transaction without commit");
queryFabcar(channel, "CAR1");
updateCarOwner(channel, "CAR1", newOwner, true);
System.out.println("after request for transaction WITH commit");
queryFabcar(channel, "CAR1");
System.out.println("Sleeping 5s");
Thread.sleep(5000); // 5secs
queryFabcar(channel, "CAR1");
System.out.println("all done");
}
private static void queryFabcar(Channel channel, String key) throws Exception {
QueryByChaincodeRequest req = client.newQueryProposalRequest();
ChaincodeID cid = ChaincodeID.newBuilder().setName("fabcar").build();
req.setChaincodeID(cid);
req.setFcn("queryCar");
req.setArgs(new String[] { key });
System.out.println("Querying for " + key);
Collection<ProposalResponse> resps = channel.queryByChaincode(req);
for (ProposalResponse resp : resps) {
String payload = new String(resp.getChaincodeActionResponsePayload());
System.out.println("response: " + payload);
}
}
private static void updateCarOwner(Channel channel, String key, String newOwner, Boolean doCommit)
throws Exception {
TransactionProposalRequest req = client.newTransactionProposalRequest();
ChaincodeID cid = ChaincodeID.newBuilder().setName("fabcar").build();
req.setChaincodeID(cid);
req.setFcn("changeCarOwner");
req.setArgs(new String[] { key, newOwner });
System.out.println("Executing for " + key);
Collection<ProposalResponse> resps = channel.sendTransactionProposal(req);
if (doCommit) {
channel.sendTransaction(resps);
}
}
}
/***
* Implementation of user. main business logic (as for fabcar example) is in
* getEnrollment - get user's private key and cert
*
*/
class SampleUser implements User {
private final String certFolder;
private final String userName;
public SampleUser(String certFolder, String userName) {
this.certFolder = certFolder;
this.userName = userName;
}
@Override
public String getName() {
return userName;
}
@Override
public Set<String> getRoles() {
return new HashSet<String>();
}
@Override
public String getAccount() {
return "";
}
@Override
public String getAffiliation() {
return "";
}
@Override
public Enrollment getEnrollment() {
return new Enrollment() {
@Override
public PrivateKey getKey() {
try {
return loadPrivateKey(Paths.get(certFolder, userName + ".priv"));
} catch (Exception e) {
return null;
}
}
@Override
public String getCert() {
try {
return new String(Files.readAllBytes(Paths.get(certFolder, userName + ".cert")));
} catch (Exception e) {
return "";
}
}
};
}
@Override
public String getMspId() {
return "Org1MSP";
}
/***
* loading private key from .pem-formatted file, ECDSA algorithm
* (from some example on StackOverflow, slightly changed)
* @param fileName - file with the key
* @return Private Key usable
* @throws IOException
* @throws GeneralSecurityException
*/
public static PrivateKey loadPrivateKey(Path fileName) throws IOException, GeneralSecurityException {
PrivateKey key = null;
InputStream is = null;
try {
is = new FileInputStream(fileName.toString());
BufferedReader br = new BufferedReader(new InputStreamReader(is));
StringBuilder builder = new StringBuilder();
boolean inKey = false;
for (String line = br.readLine(); line != null; line = br.readLine()) {
if (!inKey) {
if (line.startsWith("-----BEGIN ") && line.endsWith(" PRIVATE KEY-----")) {
inKey = true;
}
continue;
} else {
if (line.startsWith("-----END ") && line.endsWith(" PRIVATE KEY-----")) {
inKey = false;
break;
}
builder.append(line);
}
}
//
byte[] encoded = DatatypeConverter.parseBase64Binary(builder.toString());
PKCS8EncodedKeySpec keySpec = new PKCS8EncodedKeySpec(encoded);
KeyFactory kf = KeyFactory.getInstance("ECDSA");
key = kf.generatePrivate(keySpec);
} finally {
is.close();
}
return key;
}
}
これはJavaの例が提供されているリンクよりも役立つことがわかります。箱から出してすぐに、肥大化することなくエンドツーエンドのテストを提供します。 Java。