Upgrade to Spring Boot 2.7.1

- Fix H2 database support with Spring Boot 2.7+
 - Upgrade Gradle, Kotlin, Spring Mockk as well
 - Upate README.adoc accordingly

Closes gh-60
Closes gh-61

README.adoc

@@ -82,11 +82,11 @@ In order to be able to use Kotlin non-nullable properties with JPA, https://kotl
 import org.jetbrains.kotlin.gradle.tasks.KotlinCompile
 
 plugins {
-	kotlin("plugin.jpa") version "1.4.32"
-	id("org.springframework.boot") version "2.4.4"
+	kotlin("plugin.jpa") version "1.6.21"
+	id("org.springframework.boot") version "2.7.1"
 	id("io.spring.dependency-management") version "1.0.11.RELEASE"
-	kotlin("jvm") version "1.4.32"
-	kotlin("plugin.spring") version "1.4.32"
+	kotlin("jvm") version "1.6.21"
+	kotlin("plugin.spring") version "1.6.21"
 }
 ----
 
@@ -98,15 +98,12 @@ Although Java does not allow one to express null-safety in its type-system, Spri
 
 This feature can be enabled by adding the `-Xjsr305` compiler flag with the `strict` options.
 
-Notice also that Kotlin compiler is configured to generate Java 8 bytecode (Java 6 by default).
-
 `build.gradle.kts`
 [source,kotlin]
 ----
 tasks.withType<KotlinCompile> {
 	kotlinOptions {
 		freeCompilerArgs = listOf("-Xjsr305=strict")
-		jvmTarget = "1.8"
 	}
 }
 ----
@@ -135,6 +132,15 @@ dependencies {
 }
 ----
 
+Recent version of H2 requiring special configuration to properly escape reserved keywords like `user`.
+
+`src/main/resources/application.properties`
+[source,properties]
+----
+spring.jpa.properties.hibernate.globally_quoted_identifiers=true
+spring.jpa.properties.hibernate.globally_quoted_identifiers_skip_column_definitions = true
+----
+
 Spring Boot Gradle plugin automatically uses the Kotlin version declared via the Kotlin Gradle plugin.
 
 You can now take a <<understanding-generated-app, deeper look at the generated application>>.
@@ -423,7 +429,7 @@ Instead of using util classes with abstract methods like in Java, it is usual in
 `src/main/kotlin/com/example/blog/Extensions.kt`
 [source,kotlin]
 ----
-fun LocalDateTime.format() = this.format(englishDateFormatter)
+fun LocalDateTime.format(): String = this.format(englishDateFormatter)
 
 private val daysLookup = (1..31).associate { it.toLong() to getOrdinal(it) }
 
@@ -443,7 +449,7 @@ private fun getOrdinal(n: Int) = when {
 	else -> "${n}th"
 }
 
-fun String.toSlug() = toLowerCase()
+fun String.toSlug() = lowercase(Locale.getDefault())
 		.replace("\n", " ")
 		.replace("[^a-z\\d\\s]".toRegex(), " ")
 		.split(" ")
@@ -464,7 +470,7 @@ With Gradle:
 ----
 plugins {
 	...
-	kotlin("plugin.allopen") version "1.4.32"
+	kotlin("plugin.allopen") version "1.6.21"
 }
 
 allOpen {
@@ -908,7 +914,7 @@ To generate https://docs.spring.io/spring-boot/docs/current/reference/htmlsingle
 ----
 plugins {
 	...
-	kotlin("kapt") version "1.4.32"
+	kotlin("kapt") version "1.6.21"
 }
 
 dependencies {

build.gradle.kts

@@ -1,13 +1,13 @@
 import org.jetbrains.kotlin.gradle.tasks.KotlinCompile
 
 plugins {
-	id("org.springframework.boot") version "2.4.4"
+	id("org.springframework.boot") version "2.7.1"
 	id("io.spring.dependency-management") version "1.0.11.RELEASE"
-	kotlin("jvm") version "1.4.32"
-	kotlin("plugin.spring") version "1.4.32"
-	kotlin("plugin.allopen") version "1.4.32"
-	kotlin("plugin.jpa") version "1.4.32"
-	kotlin("kapt") version "1.4.32"
+	kotlin("jvm") version "1.6.21"
+	kotlin("plugin.spring") version "1.6.21"
+	kotlin("plugin.allopen") version "1.6.21"
+	kotlin("plugin.jpa") version "1.6.21"
+	kotlin("kapt") version "1.6.21"
 }
 
 group = "com.example"
@@ -34,13 +34,12 @@ dependencies {
 	}
 	testImplementation("org.junit.jupiter:junit-jupiter-api")
 	testRuntimeOnly("org.junit.jupiter:junit-jupiter-engine")
-	testImplementation("com.ninja-squad:springmockk:3.0.1")
+	testImplementation("com.ninja-squad:springmockk:3.1.1")
 }
 
 tasks.withType<KotlinCompile> {
 	kotlinOptions {
 		freeCompilerArgs = listOf("-Xjsr305=strict")
-		jvmTarget = "1.8"
 	}
 }
 

gradle/wrapper/gradle-wrapper.properties

@@ -1,5 +1,5 @@
 distributionBase=GRADLE_USER_HOME
 distributionPath=wrapper/dists
-distributionUrl=https\://services.gradle.org/distributions/gradle-6.8.3-bin.zip
+distributionUrl=https\://services.gradle.org/distributions/gradle-7.4.1-bin.zip
 zipStoreBase=GRADLE_USER_HOME
 zipStorePath=wrapper/dists

pom.xml

@@ -14,7 +14,7 @@
 	<parent>
 		<groupId>org.springframework.boot</groupId>
 		<artifactId>spring-boot-starter-parent</artifactId>
-		<version>2.4.4</version>
+		<version>2.7.1</version>
 		<relativePath/> <!-- lookup parent from repository -->
 	</parent>
 
@@ -22,7 +22,7 @@
 		<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
 		<project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
 		<java.version>1.8</java.version>
-		<kotlin.version>1.4.32</kotlin.version>
+		<kotlin.version>1.6.21</kotlin.version>
 	</properties>
 
 	<dependencies>
@@ -84,7 +84,7 @@
 		<dependency>
 			<groupId>com.ninja-squad</groupId>
 			<artifactId>springmockk</artifactId>
-			<version>3.0.1</version>
+			<version>3.1.1</version>
 			<scope>test</scope>
 		</dependency>
 	</dependencies>

src/main/kotlin/com/example/blog/Extensions.kt

@@ -5,7 +5,7 @@ import java.time.format.DateTimeFormatterBuilder
 import java.time.temporal.ChronoField
 import java.util.*
 
-fun LocalDateTime.format() = this.format(englishDateFormatter)
+fun LocalDateTime.format(): String = this.format(englishDateFormatter)
 
 private val daysLookup = (1..31).associate { it.toLong() to getOrdinal(it) }
 
@@ -25,9 +25,9 @@ private fun getOrdinal(n: Int) = when {
 	else -> "${n}th"
 }
 
-fun String.toSlug() = toLowerCase()
-		.replace("\n", " ")
-		.replace("[^a-z\\d\\s]".toRegex(), " ")
-		.split(" ")
+fun String.toSlug() = lowercase(Locale.getDefault())
+	.replace("\n", " ")
+	.replace("[^a-z\\d\\s]".toRegex(), " ")
+	.split(" ")
 		.joinToString("-")
 		.replace("-+".toRegex(), "-")

src/main/resources/application.properties

@@ -1,3 +1,6 @@
 blog.title=Blog
 blog.banner.title=Warning
 blog.banner.content=The blog will be down tomorrow.
+
+spring.jpa.properties.hibernate.globally_quoted_identifiers=true
+spring.jpa.properties.hibernate.globally_quoted_identifiers_skip_column_definitions = true