Name: blockchain-application-using-fabric-java-sdk
Owner: International Business Machines
Description: This code pattern demonstrates to create, deploy and test a blockchain network using hyperledger fabric sdk java.
Created: 2018-04-10 13:05:22.0
Updated: 2018-05-24 01:35:21.0
Pushed: 2018-05-14 11:29:50.0
Size: 497
Language: Java
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Blockchain is a shared, immutable ledger for recording the history of transactions. The Linux Foundation?s Hyperledger Fabric, the software implementation of blockchain IBM is committed to, is a permissioned network. Hyperledger Fabric is a platform for distributed ledger solutions underpinned by a modular architecture delivering high degrees of confidentiality, resiliency, flexibility and scalability.
In a Blockchain solution, the Blockchain network works as a back-end with an application front-end to communicate with the network using a SDK. To set up the communication between front-end and back-end, Hyperledger Fabric community offers a number of SDKs for a wide variety of programming languages like the NodeJS SDK and Java SDK. This code pattern explains the methodology to create, deploy and test the blockchain network using Hyperledger Fabric SDK Java.
It would be helpful for the Java developers, who started to look into Hyperledger Fabric platform and would like to use Fabric SDK Java for their projects. The SDK helps facilitate Java applications to manage the lifecycle of Hyperledger channels and user chaincode. The SDK also provides a means to execute user chaincode, query blocks and transactions on the channel, and monitor events on the channel. This code pattern will help to get the process started to build a Hyperledger Fabric v1.1 Java application.
When the reader has completed this pattern, they will understand how to create, deploy and test a blockchain network using Hyperledger Fabric SDK Java. This pattern will provision a Hyperledger Fabric 1.1 network consisting of two organizations, each maintaining two peer node, two certificate authorities (ca) for each organization and a solo ordering service. The following aspects will be demonstrated in this code pattern:
Note: This code pattern builds a Hyperledger Fabric 1.1 network and uses Hyperledger Fabric SDK java 1.0.0 .
Hyperledger Fabric: Hyperledger Fabric is a platform for distributed ledger solutions underpinned by a modular architecture delivering high degrees of confidentiality, resiliency, flexibility and scalability.
Docker: Docker is an open platform for developers and sysadmins to build, ship, and run distributed applications.
Blockchain: A blockchain is a digitized, decentralized, public ledger of all transactions in a network.
Java: Java is a general-purpose computer-programming language that is concurrent, class-based and object-oriented.
Follow these steps to setup and run this code pattern.
Clone this repo using the following command.
t clone https://github.com/IBM/blockchain-application-using-fabric-java-sdk.git
To build the blockchain network, the first step is to generate artifacts for peers and channels using cryptogen and configtx. The utilities used and steps to generate artifacts are explained here. In this pattern all required artifacts for the peers and channel of the network are already generated and provided to use as-is. Artifacts can be located at:
etwork_resources/crypto-config
etwork_resources/config
The automated scripts to build the network are provided under network
directory. The network/docker-compose.yaml
file defines the blockchain network topology. This pattern provisions a Hyperledger Fabric 1.1 network consisting of two organizations, each maintaining two peer node, two certificate authorities for each organization and a solo ordering service. Need to run the script as follows to build the network.
d network
hmod +x build.sh
/build.sh
To stop the running network, run the following script.
d network
hmod +x stop.sh
/stop.sh
To delete the network completely, following script need to execute.
d network
hmod +x teardown.sh
/teardown.sh
The previous step creates all required docker images with the appropriate configuration. To work with this network using Hyperledger Fabric SDK java 1.0.0, perform the following steps.
The java client sources are present in the folder java
of the repo.
Please check your environment before executing the next step. You should able to run mvn
commands properly.
Open a command terminal and navigate to the java
directory in the repo. Run the command mvn install
.
./java
install
A jar file blockchain-java-sdk-0.0.1-SNAPSHOT-jar-with-dependencies.jar
is built and can be found under the target
folder. This jar can be renamed to blockchain-client.jar
to keep the name short.
d target
p blockchain-java-sdk-0.0.1-SNAPSHOT-jar-with-dependencies.jar blockchain-client.jar
Copy this built jar into network_resources
directory. This is required as the java code can access required artifacts during execution.
p blockchain-client.jar ../../network_resources
In this code pattern, we create one channel mychannel
which is joined by all four peers. To create and initialize the channel, run the following command.
d ../../network_resources
ava -cp blockchain-client.jar org.app.network.CreateChannel
Output:
INFO: Deleting - users
Apr 20, 2018 5:11:45 PM org.app.network.CreateChannel main
INFO: Channel created mychannel
Apr 20, 2018 5:11:45 PM org.app.network.CreateChannel main
INFO: peer0.org1.example.com at grpc://localhost:7051
Apr 20, 2018 5:11:45 PM org.app.network.CreateChannel main
INFO: peer1.org1.example.com at grpc://localhost:7056
Apr 20, 2018 5:11:45 PM org.app.network.CreateChannel main
INFO: peer0.org2.example.com at grpc://localhost:8051
Apr 20, 2018 5:11:45 PM org.app.network.CreateChannel main
INFO: peer1.org2.example.com at grpc://localhost:8056
This code pattern uses a sample chaincode fabcar
to demo the usage of Hyperledger Fabric SDK Java APIs. To deploy and instantiate the chaincode, execute the following command.
ava -cp blockchain-client.jar org.app.network.DeployInstantiateChaincode
Output:
INFO: Deploying chaincode fabcar using Fabric client Org1MSP admin
Apr 23, 2018 10:25:22 AM org.app.network.DeployInstantiateChaincode main
INFO: fabcar- Chain code deployment SUCCESS
Apr 23, 2018 10:25:22 AM org.app.network.DeployInstantiateChaincode main
INFO: fabcar- Chain code deployment SUCCESS
Apr 23, 2018 10:25:22 AM org.app.client.FabricClient deployChainCode
INFO: Deploying chaincode fabcar using Fabric client Org2MSP admin
Apr 23, 2018 10:25:22 AM org.app.network.DeployInstantiateChaincode main
INFO: fabcar- Chain code deployment SUCCESS
Apr 23, 2018 10:25:22 AM org.app.network.DeployInstantiateChaincode main
INFO: fabcar- Chain code deployment SUCCESS
Apr 23, 2018 10:25:22 AM org.app.client.ChannelClient instantiateChainCode
INFO: Instantiate proposal request fabcar on channel mychannel with Fabric client Org2MSP admin
Apr 23, 2018 10:25:22 AM org.app.client.ChannelClient instantiateChainCode
INFO: Instantiating Chaincode ID fabcar on channel mychannel
Apr 23, 2018 10:25:25 AM org.app.client.ChannelClient instantiateChainCode
INFO: Chaincode fabcar on channel mychannel instantiation java.util.concurrent.CompletableFuture@723ca036[Not completed]
Apr 23, 2018 10:25:25 AM org.app.network.DeployInstantiateChaincode main
INFO: fabcar- Chain code instantiation SUCCESS
Apr 23, 2018 10:25:25 AM org.app.network.DeployInstantiateChaincode main
INFO: fabcar- Chain code instantiation SUCCESS
Apr 23, 2018 10:25:25 AM org.app.network.DeployInstantiateChaincode main
INFO: fabcar- Chain code instantiation SUCCESS
Apr 23, 2018 10:25:25 AM org.app.network.DeployInstantiateChaincode main
INFO: fabcar- Chain code instantiation SUCCESS
Note: The chaincode fabcar.go was taken from the fabric samples available at - https://github.com/hyperledger/fabric-samples/tree/release-1.1/chaincode/fabcar/go.
A new user can be registered and enrolled to an MSP. Execute the below command to register a new user and enroll to Org1MSP.
ava -cp blockchain-client.jar org.app.user.RegisterEnrollUser
Output:
INFO: Deleting - users
log4j:WARN No appenders could be found for logger (org.hyperledger.fabric.sdk.helper.Config).
log4j:WARN Please initialize the log4j system properly.
log4j:WARN See http://logging.apache.org/log4j/1.2/faq.html#noconfig for more info.
Apr 23, 2018 10:26:35 AM org.app.client.CAClient enrollAdminUser
INFO: CA -http://localhost:7054 Enrolled Admin.
Apr 23, 2018 10:26:35 AM org.app.client.CAClient registerUser
INFO: CA -http://localhost:7054 Registered User - user1524459395783
Apr 23, 2018 10:26:36 AM org.app.client.CAClient enrollUser
INFO: CA -http://localhost:7054 Enrolled User - user1524459395783
Blockchain network has been setup completely and is ready to use. Now we can test the network by performing invoke and query on the network. The fabcar
chaincode allows us to create a new asset which is a car. For test purpose, invoke operation is performed to create a new asset in the network and query operation is performed to list the asset of the network. Perform the following steps to check the same.
ava -cp blockchain-client.jar org.app.chaincode.invocation.InvokeChaincode
Output:
INFO: CA -http://localhost:7054 Enrolled Admin.
Apr 20, 2018 5:13:04 PM org.app.client.ChannelClient sendTransactionProposal
INFO: Sending transaction proposal on channel mychannel
Apr 20, 2018 5:13:04 PM org.app.client.ChannelClient sendTransactionProposal
INFO: Transaction proposal on channel mychannel OK SUCCESS with transaction
id:a298b9e27bdb0b6ca18b19f9c78a5371fb4d9b8dd199927baf37379537ca0d0f
Apr 20, 2018 5:13:04 PM org.app.client.ChannelClient sendTransactionProposal
INFO:
Apr 20, 2018 5:13:04 PM org.app.client.ChannelClient sendTransactionProposal
INFO: java.util.concurrent.CompletableFuture@22f31dec[Not completed]
Apr 20, 2018 5:13:04 PM org.app.chaincode.invocation.InvokeChaincode main
INFO: Invoked createCar on fabcar. Status - SUCCESS
``
ava -cp blockchain-client.jar org.app.chaincode.invocation.QueryChaincode
Output:
INFO: CA -http://localhost:7054 Enrolled Admin.
Apr 20, 2018 5:13:29 PM org.app.chaincode.invocation.QueryChaincode main
INFO: Querying for all cars ...
Apr 20, 2018 5:13:29 PM org.app.client.ChannelClient queryByChainCode
INFO: Querying queryAllCars on channel mychannel
Apr 20, 2018 5:13:29 PM org.app.chaincode.invocation.QueryChaincode main
INFO: [{"Key":"CAR1", "Record":{"make":"Chevy","model":"Volt","colour":"Red","owner":"Nick"}}]
Apr 20, 2018 5:13:39 PM org.app.chaincode.invocation.QueryChaincode main
INFO: Querying for a car - CAR1
Apr 20, 2018 5:13:39 PM org.app.client.ChannelClient queryByChainCode
INFO: Querying queryCar on channel mychannel
Apr 20, 2018 5:13:39 PM org.app.chaincode.invocation.QueryChaincode main
INFO: {"make":"Chevy","model":"Volt","colour":"Red","owner":"Nick"}