Update Jenkinsfile to use explicit JAVA_HOME

Author: vpavic

Jenkinsfile

@@ -15,7 +15,9 @@ try {
 				node('ubuntu1804') {
 					checkout scm
 					try {
-						sh './gradlew clean check --no-daemon --refresh-dependencies'
+						withEnv(["JAVA_HOME=${tool 'jdk8'}"]) {
+							sh './gradlew clean check --no-daemon --refresh-dependencies --stacktrace'
+						}
 					}
 					catch (e) {
 						currentBuild.result = 'FAILED: check'
@@ -35,7 +37,7 @@ try {
 					checkout scm
 					try {
 						withEnv(["JAVA_HOME=${tool 'jdk9'}"]) {
-							sh './gradlew clean test --no-daemon --refresh-dependencies'
+							sh './gradlew clean test --no-daemon --refresh-dependencies --stacktrace'
 						}
 					}
 					catch (e) {
@@ -53,7 +55,7 @@ try {
 					checkout scm
 					try {
 						withEnv(["JAVA_HOME=${tool 'jdk10'}"]) {
-							sh './gradlew clean test --no-daemon --refresh-dependencies'
+							sh './gradlew clean test --no-daemon --refresh-dependencies --stacktrace'
 						}
 					}
 					catch (e) {
@@ -71,7 +73,7 @@ try {
 					checkout scm
 					try {
 						withEnv(["JAVA_HOME=${tool 'jdk11'}"]) {
-							sh './gradlew clean test integrationTest --no-daemon --refresh-dependencies'
+							sh './gradlew clean test integrationTest --no-daemon --refresh-dependencies --stacktrace'
 						}
 					}
 					catch (e) {
@@ -89,7 +91,7 @@ try {
 					checkout scm
 					try {
 						withEnv(["JAVA_HOME=${tool 'openjdk12'}"]) {
-							sh './gradlew clean test integrationTest --no-daemon --refresh-dependencies'
+							sh './gradlew clean test integrationTest --no-daemon --refresh-dependencies --stacktrace'
 						}
 					}
 					catch (e) {
@@ -111,7 +113,9 @@ try {
 							withCredentials([string(credentialsId: 'spring-gpg-passphrase', variable: 'SIGNING_PASSWORD')]) {
 								withCredentials([usernamePassword(credentialsId: 'oss-token', passwordVariable: 'OSSRH_PASSWORD', usernameVariable: 'OSSRH_USERNAME')]) {
 									withCredentials([usernamePassword(credentialsId: '02bd1690-b54f-4c9f-819d-a77cb7a9822c', usernameVariable: 'ARTIFACTORY_USERNAME', passwordVariable: 'ARTIFACTORY_PASSWORD')]) {
-										sh './gradlew deployArtifacts finalizeDeployArtifacts --stacktrace --no-daemon --refresh-dependencies -Psigning.secretKeyRingFile=$SIGNING_KEYRING_FILE -Psigning.keyId=$SPRING_SIGNING_KEYID -Psigning.password=$SIGNING_PASSWORD -PossrhUsername=$OSSRH_USERNAME -PossrhPassword=$OSSRH_PASSWORD -PartifactoryUsername=$ARTIFACTORY_USERNAME -PartifactoryPassword=$ARTIFACTORY_PASSWORD'
+										withEnv(["JAVA_HOME=${tool 'jdk8'}"]) {
+											sh './gradlew deployArtifacts finalizeDeployArtifacts --no-daemon --refresh-dependencies --stacktrace -Psigning.secretKeyRingFile=$SIGNING_KEYRING_FILE -Psigning.keyId=$SPRING_SIGNING_KEYID -Psigning.password=$SIGNING_PASSWORD -PossrhUsername=$OSSRH_USERNAME -PossrhPassword=$OSSRH_PASSWORD -PartifactoryUsername=$ARTIFACTORY_USERNAME -PartifactoryPassword=$ARTIFACTORY_PASSWORD'
+										}
 									}
 								}
 							}
@@ -130,7 +134,9 @@ try {
 					checkout scm
 					try {
 						withCredentials([file(credentialsId: 'docs.spring.io-jenkins_private_ssh_key', variable: 'DEPLOY_SSH_KEY')]) {
-							sh './gradlew deployDocs --stacktrace --no-daemon --refresh-dependencies -PdeployDocsSshKeyPath=$DEPLOY_SSH_KEY -PdeployDocsSshUsername=$SPRING_DOCS_USERNAME'
+							withEnv(["JAVA_HOME=${tool 'jdk8'}"]) {
+								sh './gradlew deployDocs --no-daemon --refresh-dependencies --stacktrace -PdeployDocsSshKeyPath=$DEPLOY_SSH_KEY -PdeployDocsSshUsername=$SPRING_DOCS_USERNAME'
+							}
 						}
 					}
 					catch (e) {