Daml and Springboot integration

Questions
1

Guys I’m doing a POC on daml Springboot integration.

  1. Can anyone give me a simple smart contract on daml
  2. Now I want to interact this smart contract using Springboot
  3. I have done this two but I can’t complete fully
  4. If there is already an implementation on this please give me the GitHub link or else can anyone give me the complete code since I’m doing just a POC on this integration.
  5. Actually I want to interact through postman
  6. Kindly help me in resolving this guys
2

Hi @Dpk376 , I’m going to answer your questions one by one.

  1. Use the create-daml-app or just the skeleton app that you get with daml new to get hold of some simple smart contracts.
  2. See 3.
  3. What bit are you struggling with? What have you got working?
  4. I don’t know whether there’s an open source spring boot Daml project, but using Daml from spring boot is not necessarily different than from vanilla java. You can find java examples here: GitHub - digital-asset/ex-java-bindings: Three examples demonstrating three different approaches to using the Java ledger API bindings
  5. That shouldn’t be a problem as postman supports gRPC.
  6. Hope the above helps!
1 Like
3

When I used

daml new quickstart --template quickstart-java

I got a conflict between the spark-java package and a Jetty version loaded by some Spring dependency.

Here is my working build.gradle:

plugins {
    id 'java'
    id 'org.springframework.boot' version '3.3.2'
    id 'io.spring.dependency-management' version '1.1.6'
}

group = 'com.example'
version = '0.0.1-SNAPSHOT'

java {
    toolchain {
        languageVersion = JavaLanguageVersion.of(22)
    }
}

repositories {
    mavenCentral()
}

ext {
    set('jettyVersion', "9.4.48.v20220622")
}

dependencies {
    implementation 'org.springframework.boot:spring-boot-starter'
    implementation 'org.springframework.boot:spring-boot-starter-web'
    implementation('com.sparkjava:spark-core:2.7.2') {
        exclude group: 'org.eclipse.jetty', module: 'jetty-server'
        exclude group: 'org.eclipse.jetty', module: 'jetty-webapp'
        exclude group: 'org.eclipse.jetty.websocket', module: 'websocket-server'
        exclude group: 'org.eclipse.jetty.websocket', module: 'websocket-servlet'
    }
    implementation "org.eclipse.jetty:jetty-server:${jettyVersion}"
    implementation "org.eclipse.jetty:jetty-webapp:${jettyVersion}"
    implementation "org.eclipse.jetty:jetty-util:${jettyVersion}"
    implementation "org.eclipse.jetty:jetty-http:${jettyVersion}"
    implementation "org.eclipse.jetty:jetty-io:${jettyVersion}"

    developmentOnly 'org.springframework.boot:spring-boot-devtools'
    developmentOnly 'org.springframework.boot:spring-boot-docker-compose'

    annotationProcessor 'org.springframework.boot:spring-boot-configuration-processor'

    compileOnly 'org.projectlombok:lombok'
    annotationProcessor 'org.projectlombok:lombok'

    testImplementation 'org.springframework.boot:spring-boot-starter-test'

    implementation('com.daml:bindings-rxjava:2.9.3') {
        exclude group: 'com.google.protobuf', module: 'protobuf-lite'
    }
    implementation 'ch.qos.logback:logback-classic:1.3.12'
    implementation 'com.google.code.gson:gson:2.9.0'
    implementation 'org.springframework.boot:spring-boot-starter-actuator'
}

springBoot {
    buildInfo()
}

bootRun {
    systemProperty 'spring.profiles.active', 'default'
}

tasks.named('test') {
    useJUnitPlatform()
}

Per

1 Like