Welcome to Java SDK for Hyperledger project. 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.
The SDK acts on behave of a particular User which is defined by the embedding application through the implementation
of the SDK's User interface.
Note, the SDK does not provide a means of persistence for the application defined channels and user artifacts on the client. This is left for the embedding application to best manage. Channels may be serialized via Java serialization in the context of a client. Channels deserialized are not in an initialized state. Applications need to handle migration of serialized files between versions.
The SDK also provides a client for Hyperledger's certificate authority. The SDK is however not dependent on this
particular implementation of a certificate authority. Other Certificate authority's maybe used by implementing the
SDK's Enrollment interface.
This provides a summary of steps required to get you started with building and using the Java SDK. Please note that this is not the API documentation or a tutorial for the SDK, this will only help you familiarize to get started with the SDK if you are new in this domain.
If you don't require features of Fabric or Fabric CA version 1.3 you probably should consider the v1.2.x version of the SDK. To get the actual v1.2.0 SDK: v1.2.0 If you are trying to use new features of Fabric you will probably have to build Fabric to get those features.
| Release | Notes |
|---|---|
| 1.2 | v1.2 release notes |
| 1.1 | v1.1 release notes |
git clone https://github.com/hyperledger/fabric-sdk-java.git
cd fabric-sdk-java/
git checkout -b release-1.2
For Java applications use the latest published v1.3.x releases:
<!-- https://mvnrepository.com/artifact/org.hyperledger.fabric-sdk-java/fabric-sdk-java -->
<dependency>
<groupId>org.hyperledger.fabric-sdk-java</groupId>
<artifactId>fabric-sdk-java</artifactId>
<version>1.3.0-SNAPHOST/version>
</dependency>
- TCerts are not supported: JIRA FAB-1401
- HSM not supported. JIRA FAB-3137
*************************************************
Work in progress 1.3.0 SNAPSHOT builds can be used by adding the following to your application's pom.xml
<repositories>
<repository>
<id>snapshots-repo</id>
<url>https://oss.sonatype.org/content/repositories/snapshots</url>
<releases>
<enabled>false</enabled>
</releases>
<snapshots>
<enabled>true</enabled>
</snapshots>
</repository>
</repositories>
<dependencies>
<!-- https://mvnrepository.com/artifact/org.hyperledger.fabric-sdk-java/fabric-sdk-java -->
<dependency>
<groupId>org.hyperledger.fabric-sdk-java</groupId>
<artifactId>fabric-sdk-java</artifactId>
<version>1.3.0-SNAPSHOT</version>
</dependency>
</dependencies>
Latest Fabric builds are seldom needed except for those working on the very latest Fabric features. Some information to help with that can been found in Developer Instructions
To get a functioning Fabric v1.3.0 network needed by the SDK Integration tests once it's built.
In the directory src/test/fixture/sdkintegration issue :
./fabric.sh restart
This command needs to be rerun each time the Integration tests are run.
To get started using the Fabric Java SDK with Eclipse, refer to the instructions at: ./docs/EclipseSetup.md
SDK depends on few third party libraries that must be included in your classpath when using the JAR file. To get a list of dependencies, refer to pom.xml file or run
mvn dependency:tree or mvn dependency:list.
Alternatively, mvn dependency:analyze-report will produce a report in HTML format in target directory listing all the dependencies in a more readable format.
To build this project, the following dependencies must be met
- JDK 1.8 or above
- Apache Maven 3.5.0
Once your JAVA_HOME points to your installation of JDK 1.8 (or above) and JAVA_HOME/bin and Apache maven are in your PATH, issue the following command to build the jar file:
mvn install
or
mvn install -DskipTests
if you don't want to run the unit tests
To run the unit tests, please use mvn install which will run the unit tests and build the jar file.
Many unit tests will test failure condition's resulting in exceptions and stack traces being displayed. This is not an indication of failure!
[INFO] BUILD SUCCESS At the end is usually a very reliable indication that all tests have passed successfully!
You must be running local instances of Fabric-ca, Fabric peers, and Fabric orderers to be able to run the integration tests. See above for for how to get a Fabric network running.
Use this maven command to run the integration tests:
- mvn clean install -DskipITs=false -Dmaven.test.failure.ignore=false javadoc:javadoc
The src/test/java/org/hyperledger/fabric/sdkintegration/End2endIT.java integration test is an example of installing, instantiating, invoking and querying a chaincode.
It constructs the Hyperledger channel, deploys the GO chaincode, invokes the chaincode to do a transfer amount operation and queries the resulting blockchain world state.
The src/test/java/org/hyperledger/fabric/sdkintegration/End2endAndBackAgainIT.java Shows recreating the channel objects created in End2endIT.java and upgrading chaincode and invoking the up graded chaincode.
Between End2endIT.java and End2endAndBackAgainIT.java this code shows almost all that the SDK can do. To learn the SDK you must have some understanding first of the Fabric. Then it's best to study these two integrations tests and better yet work with them in a debugger to follow the code. ( a live demo ) Then once you understand them you can cut and paste from there to your own application. ( the code is done for you! )
The test defines one Fabric orderer and two organizations (peerOrg1, peerOrg2), each of which has 2 peers, one fabric-ca service.
Fabric requires that each organization has private keys and certificates for use in signing and verifying messages going to and from clients, peers and orderers. Each organization groups these artifacts in an MSP (Membership Service Provider) with a corresponding unique MSPID .
Furthermore, each organization is assumed to generate these artifacts independently. The fabric-ca project is an example of such a certificate generation service.
Fabric also provides the cryptogen tool to automatically generate all cryptographic artifacts needed for the end to end test.
In the directory src/test/fixture/sdkintegration/e2e-2Orgs/channel
The command used to generate end2end crypto-config artifacts:
v1.0 build/bin/cryptogen generate --config crypto-config.yaml --output=crypto-config
v1.1 cryptogen generate --config crypto-config.yaml --output=v1.1/crypto-config
For ease of assigning ports and mapping of artifacts to physical files, all peers, orderers, and fabric-ca are run as Docker containers controlled via a docker-compose configuration file.
The files used by the end to end are:
- src/test/fixture/sdkintegration/e2e-2Orgs/vX.0 (everything needed to bootstrap the orderer and create the channels)
- src/test/fixture/sdkintegration/e2e-2Orgs/vX.0crypto-config (as-is. Used by
configtxgenanddocker-composeto map the MSP directories) - src/test/fixture/sdkintegration/docker-compose.yaml
The end to end test case artifacts are stored under the directory src/test/fixture/sdkintegration/e2e-2Org/channel .
IBM Java needs the following properties defined to use TLS 1.2 to get an HTTPS connections to Fabric CA.
-Dcom.ibm.jsse2.overrideDefaultTLS=true -Dhttps.protocols=TLSv1.2
Currently, the pom.xml is set to use netty-tcnative-boringssl for TLS connection to Orderer and Peers, however, you can change the pom.xml (uncomment a few lines) to use an alternative TLS connection via ALPN.
The SDK Integration tests can be enabled by adding before the ./fabric restart the follow as:
ORG_HYPERLEDGER_FABRIC_SDKTEST_INTEGRATIONTESTS_TLS=true ORG_HYPERLEDGER_FABRIC_SDKTEST_INTEGRATIONTESTS_CA_TLS=--tls.enabled ./fabric.sh restart
Then run the Integration tests with:
ORG_HYPERLEDGER_FABRIC_SDKTEST_INTEGRATIONTESTS_TLS=true mvn clean install -DskipITs=false -Dmaven.test.failure.ignore=false javadoc:javadoc
Policies are described in the Fabric Endorsement Policies document. You create a policy using a Fabric tool ( an example is shown in JIRA issue FAB-2376) and give it to the SDK either as a file or a byte array. The SDK, in turn, will use the policy when it creates chaincode instantiation requests.
To input a policy to the SDK, use the ChaincodeEndorsementPolicy class.
For testing purposes, there are 2 policy files in the src/test/resources directory
- policyBitsAdmin ( which has policy AND(DEFAULT.admin) meaning 1 signature from the DEFAULT MSP admin' is required )
- policyBitsMember ( which has policy AND(DEFAULT.member) meaning 1 signature from a member of the DEFAULT MSP is required )
and one file in the src/test/fixture/sdkintegration/e2e-2Orgs/channel directory specifically for use in the end to end test scenario
- members_from_org1_or_2.policy ( which has policy OR(peerOrg1.member, peerOrg2.member) meaning 1 signature from a member of either organizations peerOrg1, PeerOrg2 is required)
Alternatively, you can also use ChaincodeEndorsementPolicy class by giving it a YAML file that has the policy defined in it.
See examples of this in the End2endIT testcases that use src/test/fixture/sdkintegration/chaincodeendorsementpolicy.yaml
The file chaincodeendorsementpolicy.yaml has comments that help understand how to create these policies. The first section
lists all the signature identities you can use in the policy. Currently, only ROLE types are supported.
The policy section is comprised of n-of and signed-by elements. Then n-of (1-of 2-of) require that many (n) in that
section to be true. The signed-by references an identity in the identities section.
Channel configuration files and orderer bootstrap files ( see directory src/test/fixture/sdkintegration/e2e-2Orgs ) are needed when creating a new channel.
This is created with the Hyperledger Fabric configtxgen tool. This must be run after cryptogen and the directory you're
running in must have a generated crypto-config directory.
If build/bin/configtxgen tool is not present run make configtxgen
For v1.0 integration test the commands are:
- build/bin/configtxgen -outputCreateChannelTx foo.tx -profile TwoOrgsChannel -channelID foo
- build/bin/configtxgen -outputCreateChannelTx bar.tx -profile TwoOrgsChannel -channelID bar
For v1.1 integration the commands use the v11 profiles in configtx.yaml.
You need to for now copy the configtx.yaml in e2e-20orgs to the v1.1 directory and run from there:
- configtxgen -outputBlock orderer.block -profile TwoOrgsOrdererGenesis_v11
- configtxgen -outputCreateChannelTx bar.tx -profile TwoOrgsChannel_v11 -channelID bar
- configtxgen -outputCreateChannelTx foo.tx -profile TwoOrgsChannel_v11 -channelID foo
For v1.2 integration the commands use the v12 profiles in configtx.yaml.
- configtxgen --configPath . -outputBlock orderer.block -profile TwoOrgsOrdererGenesis_v12
- configtxgen --configPath . -outputCreateChannelTx bar.tx -profile TwoOrgsChannel_v12 -channelID bar
- configtxgen --configPath . -outputCreateChannelTx foo.tx -profile TwoOrgsChannel_v12 -channelID foo
This should produce in the
v1.2directory: bar.tx,foo.tx, orderer.block
Note: The above describes how this was done. If you redo this there are private key files which are produced with unique names which won't match what's expected in the integration tests. One example of this is the docker-compose.yaml (search for _sk)
Go lang chaincode dependencies must be contained in vendor folder. For an explanation of this see Vendor folder explanation
Firewalls, load balancers, network proxies
These can sometimes silently kill a network connections and prevent them from auto reconnecting. To fix this look at
adding to Peers, EventHub's and Orderer's connection properties:
grpc.NettyChannelBuilderOption.keepAliveTime, grpc.NettyChannelBuilderOption.keepAliveTimeout,
grpc.NettyChannelBuilderOption.keepAliveWithoutCalls. Examples of this are in End2endIT.java
identity or token do not match
Keep in mind that you can perform the enrollment process with the membership services server only once, as the enrollmentSecret is a one-time-use password. If you have performed a FSUser registration/enrollment with the membership services and subsequently deleted the crypto tokens stored on the client side, the next time you try to enroll, errors similar to the ones below will be seen.
Error: identity or token do not match
Error: FSUser is already registered
To address this, remove any stored crypto material from the CA server by following the instructions here which typically involves deleting the /var/hyperledger/production directory and restarting the membership services. You will also need to remove any of the crypto tokens stored on the client side by deleting the KeyValStore . That KeyValStore is configurable and is set to ${FSUser.home}/test.properties within the unit tests.
When running the unit tests, you will always need to clean the membership services database and delete the KeyValStore file, otherwise, the unit tests will fail.
java.security.InvalidKeyException: Illegal key size
If you get this error, this means your JDK does not capable of handling unlimited strength crypto algorithms. To fix this issue, You will need to download the JCE libraries for your version of JDK. Please follow the instructions here to download and install the JCE for your version of the JDK.
Sign into Hyperledger project's Rocket chat For this you will also need a Linux Foundation ID
Join the fabric-sdk-java channel.
If your issue is with building Fabric development environment please discuss this on rocket.chat's #fabric-dev-env channel.
To report an issue please use: Hyperledger's JIRA. To login you will need a Linux Foundation ID (LFID) which you get at The Linux Foundation if you don't already have one.
JIRA Fields should be:
- Type
- Bug or New Feature
- Component
- fabric-sdk-java
- Fix Versions
- v1.3
Pleases provide as much information that you can with the issue you're experiencing: stack traces logs.
Please provide the output of java -XshowSettings:properties -version
Logging for the SDK can be enabled with setting environment variables:
ORG_HYPERLEDGER_FABRIC_SDK_LOGLEVEL=TRACE
ORG_HYPERLEDGER_FABRIC_CA_SDK_LOGLEVEL=TRACE
Fabric debug is by default enabled in the SDK docker-compose.yaml file with
On Orderer:
ORDERER_GENERAL_LOGLEVEL=debug
On peers: CORE_LOGGING_LEVEL=DEBUG
Fabric CA by starting command have the -d parameter.
Upload full logs to the JIRA not just where the issue occurred if possible
This work is licensed under a Creative Commons Attribution 4.0 International License.
