Develop Reference

How do you parameterize the Spring Boot Gradle plugin?

We are looking to migrate from Maven to Gradle, and have worked through most of the challenges you would expect for replacing the parent POM concept. There is one sticky point that we haven't figured out yet. We need to specify the version of Spring Boot we are using globally, but I run into invalid build file problems with both of the solutions I've tried:
I tried putting the plugins { id 'org.springframework.boot' version '2.1.17.RELEASE' } declaration in the common build script. Build error, "Only Project and Settings build scripts can contain plugins {} blocks."
I tried calling the common build file to specify the springBootVersion parameter and using that in the plugins declaration. Build Error, "only buildscript {} and other plugins {} script blocks are allowed before plugins {} blocks, no other statements are allowed"
All of this would be easier if I could simply apply plugin: 'org.springframework.boot' but then Gradle can't find the plugin. All but one microservice are on a single version of Spring Boot, and we want to be able to upgrade globally if possible.
Additional Information
I have ~40 microservices plus some libraries used by those services
Separate repository for each of them, so the normal parent/child approach does not work
Maven parent POMs allowed you to publish that POM as it's own resource, and there is no 1:1 equivalent feature in Gradle
Gradle pluginManagement concept also doesn't work for us because it resolves the Spring Boot plugin but the dependency management plugin now can't be found.
My common build script is included here:
repositories {
mavenLocal()
/* Removed our internal repositories */
jcenter()
mavenCentral()
}
apply plugin: 'java'
apply plugin: 'jacoco'
apply plugin: 'maven-publish'
apply plugin: 'io.spring.dependency-management'
group = 'nedl-unified-platform'
/* Required to publish Spring Boot microservices to publish to repository */
configurations {
[apiElements, runtimeElements].each {
it.outgoing.artifacts.removeIf { it.buildDependencies.getDependencies(null).contains(jar) }
it.outgoing.artifact(bootJar)
}
}
java {
sourceCompatibility = JavaVersion.VERSION_11
targetCompatibility = JavaVersion.VERSION_11
withJavadocJar()
withSourcesJar()
}
ext {
set('springBootVersion', '2.1.17.RELEASE')
set('springCloudVersion', "Greenwich.SR6")
}
dependencyManagement {
imports {
mavenBom "org.springframework.cloud:spring-cloud-dependencies:${springCloudVersion}"
}
}
jacoco {
toolVersion = "0.8.5"
reportsDir = file("$buildDir/reports/jacoco")
}
test {
finalizedBy jacocoTestReport // report is always generated after tests run
}
jacocoTestCoverageVerification {
violationRules {
rule {
limit {
minimum = 0.2
}
}
}
}
jacocoTestReport {
dependsOn test // tests are required to run before generating the report
reports {
xml.enabled true
html.destination file("${reportsDir}/jacocoHtml")
xml.destination file("${reportsDir}/jacocoReport.xml")
}
}
tasks.withType(JavaCompile) {
options.encoding = 'UTF-8'
}
publishing {
publications {
maven(MavenPublication) {
from components.java
}
}
repositories {
/* excluded for privacy and brevity's sake, our internal Maven repo */
}
}
And that is called by our project build script that I want to parameterize:
plugins {
id 'org.springframework.boot' version springBootVersion
}
apply from: "https://mycentral.repo/project-common/develop/build.gradle"
dependencies {
implementation 'org.springframework.boot:spring-boot-starter-actuator'
implementation 'org.springframework.cloud:spring-cloud-starter-netflix-eureka-server'
implementation 'ch.qos.logback:logback-classic'
implementation 'javax.annotation:javax.annotation-api:1.3.2'
implementation 'javax.xml.bind:jaxb-api:2.4.0-b180830.0359'
implementation 'org.glassfish.jaxb:jaxb-runtime:2.4.0-b180830.0438'
testImplementation 'org.springframework.boot:spring-boot-starter-test'
}
version = '0.0.2-SNAPSHOT'

I think the gap here is that in maven you have the concept of a parent pom, whereas in Gradle you don't. There is no 1:1 mapping to this like you say, but you can have plugins in Gradle, and apply a plugin.
The closest thing you would have is if you developed your own Gradle plugin, which each of your projects could apply. Your custom plugin would then configure Spring Boot among whatever else is common to all your projects. This plugin would define the version of Spring Boot you want all your other projects to use.
You wouldn't get much benefit to a custom plugin if it's only concern is configuring Spring Boot, it would need to do other things as well. It can be difficult to create a Gradle plugin when you don't have allot of experience in it. You lose all the familiar syntax to the build.gradle and you literally have to write code, (there are some similarities but I have found it difficult), I would avoid it if possible.
I would suggest you start off by applying the spring boot plugin directly to one of your microservices projects, get that working, then do another. After you have done a number of them you will then be able to see what is common between them, and if it is indeed worth investing into developing a global plugin. You really need to be careful though because your global plugin has the potential to be both a blessing and curse. It may take away allot of manual work for maintainers, but if you get it wrong it will cause them grief, and then they will want to go back to maven.
I'm not sure if I understand your globally defined Spring version requirement. Unless you are using SNAPSHOT dependencies/plugins (bad don't do that), (or a black magic settings.gralde outside of your repo), you will have to put some version somewhere. As an alternative you could create your own custom task which runs on the check lifecycle which will check the version of spring (or your plugin) and print a warning if it's not the latest version, and encourage the developer to upgrade.
Extra Info
Parameterizing plugins with properties can be done putting your property in gradle.properties as springBootVersion=2.1.17.RELEASE .

I'm not sure I understood your issue perfectly but you should use the Gradle way for sharing configuration : the root project config.
Instead of including the common build script in every project, create a global project and set the configuration here.
root
|
| --- projectA
| --- projectB
| --- projectC
With the according settings.gradle
include 'projectA'
include 'projectB'
include 'projectC'
In the root build.gradle, set up the version
ext.springBootVersion = '2.1.17.RELEASE'
In subprojects using springBoot, let's say projectB, apply the plugin in the sub build.gradle
buildscript {
repositories {
jcenter()
mavenCentral()
}
dependencies {
classpath "org.springframework.boot:spring-boot-gradle-plugin:$springBootVersion"
}
}
apply plugin: 'org.springframework.boot'

This example works for me, though I may not understand all of the constraints.
If we abstract the version of Spring Boot behind a fixed URI (e.g. on an internal CI/CD server), then consider this in each project/repo's build.gradle:
buildscript {
repositories {
jcenter()
}
def SPRING_BOOT_VERSION_URI = 'http://localhost:5151/api-server/spring-boot.txt'
ext.springBootVersion = new URL(SPRING_BOOT_VERSION_URI).getText().trim()
dependencies {
classpath "org.springframework.boot:spring-boot-gradle-plugin:$springBootVersion"
}
}
apply plugin: 'org.springframework.boot'
apply from: "../common/build.gradle"
I realize the original question states that the apply plugin doesn't work, but it's not clear to me if that precludes this method.
Finally, note that it is easy to expand this beyond a simple text-file to be a more formal JSON specification (tailored to the teams' needs).

If you add this to the root project, all child projects should be able to just import from the same set of Spring Boot dependencies. The magic ingredient is the allprojects block:
buildscript {
repositories {
maven { url "https://plugins.gradle.org/m2/" }
}
dependencies {
classpath("org.springframework.boot:spring-boot-gradle-plugin:${springBootVersion}")
}
}
ext {
springBootVersion = '2.3.4.RELEASE'
}
allprojects {
apply plugin: 'java'
apply plugin: 'io.spring.dependency-management'
dependencyManagement {
imports {
mavenBom("org.springframework.boot:spring-boot-dependencies:${springBootVersion}")
}
}
}
apply plugin: 'org.springframework.boot'

How do I set up APT for Immutables such that Intellij Idea will recognize the generated code?

I'm looking into migrating from maven to gradle, in this case, gradle itself seems to be working fine, but Idea isn't recognizing the source code that Immutables is generating.
I've read this blog post on APT, it's how I got this for.
/*
* This build file was generated by the Gradle 'init' task.
*
* This generated file contains a commented-out sample Java project to get you started.
* For more details take a look at the Java Quickstart chapter in the Gradle
* user guide available at https://docs.gradle.org/4.3/userguide/tutorial_java_projects.html
*/
// Apply the java plugin to add support for Java
apply plugin: 'java-library'
apply plugin: 'idea'
buildscript {
repositories {
maven {
url 'https://d3vfm0n2cffdwd.cloudfront.net'
}
jcenter()
}
dependencies {
classpath 'io.spring.gradle:dependency-management-plugin:1.0.0.RELEASE'
}
}
apply plugin: 'io.spring.dependency-management'
dependencyManagement {
imports {
mavenBom 'com.xenoterracide:platform:0.1.39-SNAPSHOT'
}
}
repositories {
maven {
url 'https://d3vfm0n2cffdwd.cloudfront.net'
}
jcenter()
}
configurations {
apt
aptCompile
}
// In this section you declare the dependencies for your production and test code
dependencies {
implementation 'com.google.guava:guava'
aptCompile 'org.immutables:value'
compileOnly 'org.immutables:value'
apt 'org.immutables:builder'
// The production code uses the SLF4J logging API at compile time
implementation 'org.slf4j:slf4j-api'
// Declare the dependency for your favourite test framework you want to use in your tests.
// TestNG is also supported by the Gradle Test task. Just change the
// testCompile dependency to testCompile 'org.testng:testng:6.8.1' and add
// 'test.useTestNG()' to your build script.
testImplementation 'junit:junit'
testImplementation 'org.assertj:assertj-core'
testImplementation 'org.mockito:mockito-core'
testImplementation 'org.hamcrest:hamcrest-library'
}
compileJava {
options.annotationProcessorPath = configurations.aptCompile
}
for more code see bitbucket
one of the things that's getting me, is that depending on what I've tried the generated java either ends up in an out directory, or build on the classpath, of course so far neither of these solves the problem.
how do I fix this so that Idea can see the source for the generated types (so that it's not all highlighted in red)?

#CrazyCoder's links helped me get closer to a solution, this seems to resolve it though.
idea {
module {
sourceDirs += file("out/production/classes/generated")
}
}

How to setup a Java Gradle plugin project in IntelliJ?

I'm having issues setting up a Java Gradle Plugin project for IntelliJ.
Specifically, I can't get the Java to import the required gradle library.
import org.gradle.api.Plugin;
import org.gradle.api.Project;

I found the answer for Groovy and ported it over for Java.
Insure you have gradle downloaded, and the gradle bin directory added to your path.
Create a new directory for your project to exist in. Open up command prompt, and run the following command:
gradle init --type java-library
Then edit the generated build.gradle file and add the following the the dependencies:
compile gradleApi()
Also and the following:
apply plugin: 'idea'
This should result in a build.gradle that looks like:
// Apply the java plugin to add support for Java
apply plugin: 'java'
apply plugin: 'idea'
// In this section you declare where to find the dependencies of your project
repositories {
// Use jcenter for resolving your dependencies.
// You can declare any Maven/Ivy/file repository here.
jcenter()
}
dependencies {
compile gradleApi()
// The production code uses Guava
compile 'com.google.guava:guava:20.0'
// Use JUnit test framework
testCompile 'junit:junit:4.12'
}
Then back in command prompt, run:
gradlew idea
And open the generated project in IntelliJ
Groovy Source: How to setup a Gradle plugin project in IntelliJ?

How to export a Spring Boot project to an executable standalone file?

I have created a project in Spring Tool Suite with Spring Boot and Gradle, and I really don't know how to export to make it work.
I don't know much about gradle, just the basics to add dependencies from the maven repository. So in some articles says to apply the application plugin to do the task, but I don't know how to set up the configuration file and how to create the executable.
If anyone could write or link a step by step detailed explanation on how to do it, it would be very much appreciated.
This is my build.gradle file:
buildscript {
repositories {
mavenCentral()
}
dependencies {
classpath("org.springframework.boot:spring-boot-gradle-plugin:1.3.1.RELEASE")
}
}
apply plugin: 'java'
apply plugin: 'eclipse'
apply plugin: 'spring-boot'
springBoot {
mainClass = "com.rodamientosbulnes.objetivosventa.Application"
executable = true
}
jar {
baseName = 'objetivosventa'
version = '0.1.0'
}
repositories {
mavenCentral()
}
sourceCompatibility = 1.8
targetCompatibility = 1.8
dependencies {
compile('org.springframework.boot:spring-boot-starter')
compile('org.springframework:spring-jdbc')
compile('net.sourceforge.jtds:jtds:1.3.1')
compile('org.apache.poi:poi-ooxml:3.13')
compile('com.miglayout:miglayout-swing:4.2')
}
task wrapper(type: Wrapper) {
gradleVersion = '2.3'
}

Build file looks fine, you only need to run gradle build (or Run As -> Gradle -> Gradle build in the STS) to create the runnable jar.
More details about configuration of the gradle plugin are available on spring boot documentation site.

Gradle's application plugin doesn't make a single execitable for you, but it can create a distribution, which includes all the dependencies, jar-artifact for your project and 2 scripts to run it (one batch-file and linex executable).
The main thing you need to know, is that spring-boot plugin already provide all the task from application plugin you may need. All the task you can find here. You need distZip or installDist to package your project to the distribution. This task will create a ready project distribution under your project-folder/build folder. One more task you may find usefull is buildRun which will run you spring-boot application without package it into distribution.

Why do xml configs of gradle dependencies go with "Gradle__" prefix? Intellij IDEA 13

Java Spring project with Gradle 1.9 and vertx. Local gradle distribution.
Some lines of build.gradle
apply plugin 'java'
apply plugin 'groovy'
apply plugin 'idea'
buildscript {
repositories {
jcenter()
}
}
repositories {
mavenCentral()
}
dependencies {
...
compile 'org.springframework:spring-context-support:3.2.5.RELEASE'
compile 'org.springframework:spring-aop:3.2.5.RELEASE'
compile 'org.springframework:spring-aspects:3.2.5.RELEASE'
...
}
I have an existing gradle project downloaded from git with xml configs in .idea/libraries folder named spring-aop_3_2_5_RELEASE.xml, for example, where we can find xml tag <library name="spring-aop-3.2.5.RELEASE">...</library>.
After I had imported this project new file Gradle__spring-aop_3_2_5_RELEASE.xml appeared with only difference in name attribute of the library tag: Gradle: spring-aop-3.2.5.RELEASE. So i have duplicate xml configs for dependencies. I wonder why my gradle added that prefix.

The prefix is hardcoded, IDEA 13 needs a reimport of your old Gradle projects that were created in IDEA 12. It's not obvious, but there will be a notification about it in the next update.
In the Gradle generated project you can exclude the library files from the version control, same for the .iml files that can be also ignored when using Maven. Other files can be still shared (like code style, run configurations, inspection profiles, etc). Check this document for details.