Test with Java 20 in CI.

See #2536

Jenkinsfile

@@ -18,9 +18,9 @@ pipeline {
 	}
 
 	stages {
-		stage("Docker images") {
+		stage("Docker Images") {
 			parallel {
-				stage('Publish JDK 17 + Redis 6.2 Docker image') {
+				stage('Publish JDK 17 + Redis 6.2 Docker Image') {
 					when {
 						anyOf {
 							changeset "ci/openjdk17-redis-6.2/Dockerfile"
@@ -40,6 +40,26 @@ pipeline {
 						}
 					}
 				}
+				stage('Publish JDK 20 + Redis 6.2 Docker Image') {
+					when {
+						anyOf {
+							changeset "ci/openjdk20-redis-6.2/Dockerfile"
+							changeset "Makefile"
+							changeset "ci/pipeline.properties"
+						}
+					}
+					agent { label 'data' }
+					options { timeout(time: 20, unit: 'MINUTES') }
+
+					steps {
+						script {
+							def image = docker.build("springci/spring-data-with-redis-6.2:${p['java.next.tag']}", "--build-arg BASE=${p['docker.java.next.image']} --build-arg REDIS=${p['docker.redis.6.version']} -f ci/openjdk20-redis-6.2/Dockerfile .")
+							docker.withRegistry(p['docker.registry'], p['docker.credentials']) {
+								image.push()
+							}
+						}
+					}
+				}
 			}
 		}
 
@@ -67,7 +87,7 @@ pipeline {
 			}
 		}
 
-		stage("test: native-hints") {
+		stage("Test other configurations") {
         	when {
         		beforeAgent(true)
         		anyOf {
@@ -75,19 +95,39 @@ pipeline {
         			not { triggeredBy 'UpstreamCause' }
         		}
         	}
-        	agent {
-        		label 'data'
-        	}
-        	options { timeout(time: 30, unit: 'MINUTES') }
-        	environment {
-        		ARTIFACTORY = credentials("${p['artifactory.credentials']}")
-        	}
-        	steps {
-        		script {
-        			docker.image("harbor-repo.vmware.com/dockerhub-proxy-cache/springci/spring-data-with-redis-6.2:${p['java.main.tag']}").inside('-v $HOME:/tmp/jenkins-home') {
-        				sh 'PROFILE=runtimehints LONG_TESTS=false ci/test.sh'
-        			}
-        		}
+        	parallel {
+				stage("test: native-hints") {
+					agent {
+						label 'data'
+					}
+					options { timeout(time: 30, unit: 'MINUTES') }
+					environment {
+						ARTIFACTORY = credentials("${p['artifactory.credentials']}")
+					}
+					steps {
+						script {
+							docker.image("harbor-repo.vmware.com/dockerhub-proxy-cache/springci/spring-data-with-redis-6.2:${p['java.main.tag']}").inside('-v $HOME:/tmp/jenkins-home') {
+								sh 'PROFILE=runtimehints LONG_TESTS=false ci/test.sh'
+							}
+						}
+					}
+				}
+				stage("test: baseline (Java 20)") {
+					agent {
+						label 'data'
+					}
+					options { timeout(time: 30, unit: 'MINUTES') }
+					environment {
+						ARTIFACTORY = credentials("${p['artifactory.credentials']}")
+					}
+					steps {
+						script {
+							docker.image("harbor-repo.vmware.com/dockerhub-proxy-cache/springci/spring-data-with-redis-6.2:${p['java.next.tag']}").inside('-v $HOME:/tmp/jenkins-home') {
+								sh 'PROFILE=none LONG_TESTS=true ci/test.sh'
+							}
+						}
+					}
+				}
         	}
         }
 

ci/openjdk20-redis-6.2/Dockerfile

@@ -0,0 +1,16 @@
+ARG BASE
+FROM ${BASE}
+# Any ARG statements before FROM are cleared.
+ARG REDIS
+
+# Copy Spring Data Redis's Makefile into the container
+COPY ./Makefile /
+
+RUN set -eux; \
+#	sed -i -e 's/http/https/g' /etc/apt/sources.list ; \
+	apt-get update ; \
+	apt-get install -y build-essential ; \
+	make work/redis/bin/redis-cli work/redis/bin/redis-server REDIS_VERSION=${REDIS}; \
+	chmod -R o+rw work; \
+	apt-get clean; \
+	rm -rf /var/lib/apt/lists/*;