CorDapp Template - Java
Welcome to the Java CorDapp template. The CorDapp template is a stubbed-out CorDapp that you can use to bootstrap your own CorDapps.
This is the Java version of the CorDapp template. The Kotlin equivalent is here.
Pre-Requisites
See https://docs.corda.net/getting-set-up.html.
Usage
Running tests inside IntelliJ
We recommend editing your IntelliJ preferences so that you use the Gradle runner - this means that the quasar utils
plugin will make sure that some flags (like -javaagent
- see below) are
set for you.
To switch to using the Gradle runner:
- Navigate to
Build, Execution, Deployment -> Build Tools -> Gradle -> Runner
(or search forrunner
)- Windows: this is in "Settings"
- MacOS: this is in "Preferences"
- Set "Delegate IDE build/run actions to gradle" to true
- Set "Run test using:" to "Gradle Test Runner"
If you would prefer to use the built in IntelliJ JUnit test runner, you can run gradlew installQuasar
which will
copy your quasar JAR file to the lib directory. You will then need to specify -javaagent:lib/quasar.jar
and set the run directory to the project root directory for each test.
Running the nodes
See https://docs.corda.net/tutorial-cordapp.html#running-the-example-cordapp.
Interacting with the nodes
Shell
When started via the command line, each node will display an interactive shell:
Welcome to the Corda interactive shell.
Useful commands include 'help' to see what is available, and 'bye' to shut down the node.
Tue Nov 06 11:58:13 GMT 2018>>>
You can use this shell to interact with your node. For example, enter run networkMapSnapshot
to see a list of
the other nodes on the network:
Tue Nov 06 11:58:13 GMT 2018>>> run networkMapSnapshot
[
{
"addresses" : [ "localhost:10002" ],
"legalIdentitiesAndCerts" : [ "O=Notary, L=London, C=GB" ],
"platformVersion" : 3,
"serial" : 1541505484825
},
{
"addresses" : [ "localhost:10005" ],
"legalIdentitiesAndCerts" : [ "O=PartyA, L=London, C=GB" ],
"platformVersion" : 3,
"serial" : 1541505382560
},
{
"addresses" : [ "localhost:10008" ],
"legalIdentitiesAndCerts" : [ "O=PartyB, L=New York, C=US" ],
"platformVersion" : 3,
"serial" : 1541505384742
}
]
Tue Nov 06 12:30:11 GMT 2018>>>
You can find out more about the node shell here.
Client
clients/src/main/java/com/template/Client.java
defines a simple command-line client that connects to a node via RPC
and prints a list of the other nodes on the network.
Running the client
Via the command line
Run the runTemplateClient
Gradle task. By default, it connects to the node with RPC address localhost:10006
with
the username user1
and the password test
.
Via IntelliJ
Run the Run Template Client
run configuration. By default, it connects to the node with RPC address localhost:10006
with the username user1
and the password test
.
Webserver
clients/src/main/java/com/template/webserver/
defines a simple Spring webserver that connects to a node via RPC and
allows you to interact with the node over HTTP.
The API endpoints are defined here:
clients/src/main/java/com/template/webserver/Controller.java
And a static webpage is defined here:
clients/src/main/resources/static/
Running the webserver
Via the command line
Run the runTemplateServer
Gradle task. By default, it connects to the node with RPC address localhost:10006
with
the username user1
and the password test
, and serves the webserver on port localhost:10050
.
Via IntelliJ
Run the Run Template Server
run configuration. By default, it connects to the node with RPC address localhost:10006
with the username user1
and the password test
, and serves the webserver on port localhost:10050
.
Interacting with the webserver
The static webpage is served on:
http://localhost:10050
While the sole template endpoint is served on:
http://localhost:10050/templateendpoint
Extending the template
You should extend this template as follows:
- Add your own state and contract definitions under
contracts/src/main/java/
- Add your own flow definitions under
workflows/src/main/java/
- Extend or replace the client and webserver under
clients/src/main/java/
For a guided example of how to extend this template, see the Hello, World! tutorial here.