chore: Cleanup examples-spring-boot-hibernate5

- `application.yml`: Format properly with 2 spaces remove unused config.
- `Application`: Exclude `HibernateJpaAutoConfiguration` to avoid duplicate transaction managers: java.lang.ClassCastException: class org.springframework.orm.jpa.EntityManagerHolder cannot be cast to class org.springframework.orm.hibernate5.SessionHolder (org.springframework.orm.jpa.EntityManagerHolder and org.springframework.orm.hibernate5.SessionHolder are in unnamed module of loader 'app')
- `BookController`: Add `@ReadOnly` to `books()` action to get a session for the `Book.list()` method.
- `build.gradle`: Use correct dependencies and narrow the scopes. Switch from `tomcat-jdbc` to `HikariCP` as this will be the new default. Apply Gradle plugins in subproject instead of having logic and conditions in the root build file apply them - much easier to see what's being applied. Add version variable `springBootGradlePluginVersion`.

Author: matrei

examples/spring-boot-hibernate5/build.gradle

@@ -1,37 +1,28 @@
-
 buildscript {
     repositories {
         mavenCentral()
     }
     dependencies {
-        classpath("org.springframework.boot:spring-boot-gradle-plugin:3.3.5")
+        classpath "org.springframework.boot:spring-boot-gradle-plugin:$springBootGradlePluginVersion"
     }
 }
 
-apply plugin: 'java'
+apply plugin: 'groovy'
 apply plugin: 'org.springframework.boot'
-apply plugin: "groovy"
 
-group 'examples'
+version = rootProject.version
+group = 'examples'
 
 dependencies {
-    implementation platform("org.grails:grails-bom:$grailsVersion")
-    implementation("org.springframework.boot:spring-boot-starter")
-    implementation("org.springframework.boot:spring-boot-starter-web")
-    implementation "org.springframework.boot:spring-boot-autoconfigure"
-    implementation "org.springframework.boot:spring-boot-starter-tomcat"
-    implementation project(":gorm-hibernate5-spring-boot")
-    implementation "org.hibernate:hibernate-core-jakarta:$hibernateVersion"
-    implementation "org.hibernate:hibernate-ehcache:$hibernateVersion"
-
-    runtimeOnly "com.h2database:h2"
-    runtimeOnly "org.apache.tomcat:tomcat-jdbc"
-    runtimeOnly "org.apache.tomcat.embed:tomcat-embed-logging-log4j:$tomcatLog4jVersion"
-    runtimeOnly "org.slf4j:slf4j-api"
 
-    testImplementation "org.spockframework:spock-core"
+    implementation project(':gorm-hibernate5-spring-boot')
+    implementation 'org.springframework.boot:spring-boot-starter-web'
 
-    testRuntimeOnly "org.slf4j:slf4j-simple"
+    runtimeOnly 'com.h2database:h2'
+    runtimeOnly 'com.zaxxer:HikariCP'
+    runtimeOnly 'org.springframework.boot:spring-boot-autoconfigure'
+    runtimeOnly 'org.springframework.boot:spring-boot-starter-logging'
+    runtimeOnly 'org.springframework.boot:spring-boot-starter-tomcat'
 
-    testImplementation('org.springframework.boot:spring-boot-starter-test')
+    testImplementation 'org.spockframework:spock-core'
 }

examples/spring-boot-hibernate5/src/main/groovy/example/Application.groovy

@@ -5,9 +5,10 @@ import groovy.transform.CompileStatic
 import org.springframework.boot.CommandLineRunner
 import org.springframework.boot.SpringApplication
 import org.springframework.boot.autoconfigure.SpringBootApplication
+import org.springframework.boot.autoconfigure.orm.jpa.HibernateJpaAutoConfiguration
 
-@SpringBootApplication
 @CompileStatic
+@SpringBootApplication(exclude = HibernateJpaAutoConfiguration)
 class Application implements CommandLineRunner {
 
     static void main(String[] args) throws Exception {

examples/spring-boot-hibernate5/src/main/groovy/example/BookController.groovy

@@ -1,18 +1,20 @@
 package example
 
+import grails.gorm.transactions.ReadOnly
 import groovy.transform.CompileStatic
 import org.springframework.beans.factory.annotation.Autowired
 import org.springframework.web.bind.annotation.PathVariable
 import org.springframework.web.bind.annotation.RequestMapping
 import org.springframework.web.bind.annotation.RestController
 
-@RestController
 @CompileStatic
+@RestController
 class BookController {
 
     @Autowired
     BookService bookService
 
+    @ReadOnly
     @RequestMapping("/books")
     List<Book> books() {
         Book.list()

examples/spring-boot-hibernate5/src/main/resources/application.yml

@@ -1,12 +1,10 @@
 hibernate:
-    cache:
-        queries: false
-        use_second_level_cache: true
-        use_query_cache: false
-        region.factory_class: 'org.hibernate.cache.ehcache.EhCacheRegionFactory'
+  cache:
+    queries: false
+    use_second_level_cache: false
+    use_query_cache: false
 dataSource:
-    pooled: true
-    jmxExport: true
-    driverClassName: org.h2.Driver
-    dbCreate: create-drop
-    url: jdbc:h2:mem:devDb;LOCK_TIMEOUT=10000;DB_CLOSE_ON_EXIT=FALSE
+  pooled: true
+  driverClassName: org.h2.Driver
+  dbCreate: create-drop
+  url: jdbc:h2:mem:devDb;LOCK_TIMEOUT=10000;DB_CLOSE_ON_EXIT=FALSE

gradle.properties

@@ -19,6 +19,7 @@ picocliVersion=4.7.6
 snakeYamlVersion=2.3
 slf4jVersion=2.0.16
 spockVersion=2.3-groovy-4.0
+springBootGradlePluginVersion=3.3.5
 testingSupportVersion=4.0.0-SNAPSHOT
 tomcatLog4jVersion=8.5.2
 tomcatVersion=10.1.31