diff --git a/gradle/wrapper/gradle-wrapper.properties b/gradle/wrapper/gradle-wrapper.properties
index 070cb70..e411586 100644
--- a/gradle/wrapper/gradle-wrapper.properties
+++ b/gradle/wrapper/gradle-wrapper.properties
@@ -1,5 +1,5 @@
 distributionBase=GRADLE_USER_HOME
 distributionPath=wrapper/dists
-distributionUrl=https\://services.gradle.org/distributions/gradle-7.6-bin.zip
+distributionUrl=https\://services.gradle.org/distributions/gradle-8.4-bin.zip
 zipStoreBase=GRADLE_USER_HOME
 zipStorePath=wrapper/dists
diff --git a/projects/01-java-app/build.gradle b/projects/01-java-app/build.gradle
index b453883..5f7ce04 100644
--- a/projects/01-java-app/build.gradle
+++ b/projects/01-java-app/build.gradle
@@ -1,8 +1,3 @@
-//plugins {
-//    id 'soramitsu'
-//    id 'application'
-//}
-
 buildscript {
     repositories {
         mavenLocal()
@@ -11,6 +6,7 @@ buildscript {
         dependencies { classpath 'jp.co.soramitsu:sora-plugin:+' }
     }
 }
+
 apply plugin: 'jp.co.soramitsu.sora-plugin'
 apply plugin: 'application'
 apply plugin: 'java'
@@ -31,9 +27,9 @@ soramitsu {
         baseImage = 'openjdk:11-jre-slim'
         jar = new File("build/libs/${project.name}-${project.version}.jar")
         files = [
-                "build.gradle":"/build.gradle",
+                "build.gradle"   : "/build.gradle",
                 "settings.gradle": "/1/settings.gradle",
-                "gradlew": "/1/2/gradlew"
+                "gradlew"        : "/1/2/gradlew"
         ]
     }
 }
diff --git a/projects/01-java-app/gradle/wrapper/gradle-wrapper.properties b/projects/01-java-app/gradle/wrapper/gradle-wrapper.properties
index 070cb70..e411586 100644
--- a/projects/01-java-app/gradle/wrapper/gradle-wrapper.properties
+++ b/projects/01-java-app/gradle/wrapper/gradle-wrapper.properties
@@ -1,5 +1,5 @@
 distributionBase=GRADLE_USER_HOME
 distributionPath=wrapper/dists
-distributionUrl=https\://services.gradle.org/distributions/gradle-7.6-bin.zip
+distributionUrl=https\://services.gradle.org/distributions/gradle-8.4-bin.zip
 zipStoreBase=GRADLE_USER_HOME
 zipStorePath=wrapper/dists
diff --git a/projects/02-java-lib/gradle/wrapper/gradle-wrapper.properties b/projects/02-java-lib/gradle/wrapper/gradle-wrapper.properties
index 070cb70..e411586 100644
--- a/projects/02-java-lib/gradle/wrapper/gradle-wrapper.properties
+++ b/projects/02-java-lib/gradle/wrapper/gradle-wrapper.properties
@@ -1,5 +1,5 @@
 distributionBase=GRADLE_USER_HOME
 distributionPath=wrapper/dists
-distributionUrl=https\://services.gradle.org/distributions/gradle-7.6-bin.zip
+distributionUrl=https\://services.gradle.org/distributions/gradle-8.4-bin.zip
 zipStoreBase=GRADLE_USER_HOME
 zipStorePath=wrapper/dists
diff --git a/projects/03-kotlin-app/gradle/wrapper/gradle-wrapper.properties b/projects/03-kotlin-app/gradle/wrapper/gradle-wrapper.properties
index 070cb70..e411586 100644
--- a/projects/03-kotlin-app/gradle/wrapper/gradle-wrapper.properties
+++ b/projects/03-kotlin-app/gradle/wrapper/gradle-wrapper.properties
@@ -1,5 +1,5 @@
 distributionBase=GRADLE_USER_HOME
 distributionPath=wrapper/dists
-distributionUrl=https\://services.gradle.org/distributions/gradle-7.6-bin.zip
+distributionUrl=https\://services.gradle.org/distributions/gradle-8.4-bin.zip
 zipStoreBase=GRADLE_USER_HOME
 zipStorePath=wrapper/dists
diff --git a/projects/04-kotlin-lib/gradle/wrapper/gradle-wrapper.properties b/projects/04-kotlin-lib/gradle/wrapper/gradle-wrapper.properties
index 070cb70..e411586 100644
--- a/projects/04-kotlin-lib/gradle/wrapper/gradle-wrapper.properties
+++ b/projects/04-kotlin-lib/gradle/wrapper/gradle-wrapper.properties
@@ -1,5 +1,5 @@
 distributionBase=GRADLE_USER_HOME
 distributionPath=wrapper/dists
-distributionUrl=https\://services.gradle.org/distributions/gradle-7.6-bin.zip
+distributionUrl=https\://services.gradle.org/distributions/gradle-8.4-bin.zip
 zipStoreBase=GRADLE_USER_HOME
 zipStorePath=wrapper/dists
diff --git a/projects/05-java-spring-app/gradle/wrapper/gradle-wrapper.properties b/projects/05-java-spring-app/gradle/wrapper/gradle-wrapper.properties
index 070cb70..e411586 100644
--- a/projects/05-java-spring-app/gradle/wrapper/gradle-wrapper.properties
+++ b/projects/05-java-spring-app/gradle/wrapper/gradle-wrapper.properties
@@ -1,5 +1,5 @@
 distributionBase=GRADLE_USER_HOME
 distributionPath=wrapper/dists
-distributionUrl=https\://services.gradle.org/distributions/gradle-7.6-bin.zip
+distributionUrl=https\://services.gradle.org/distributions/gradle-8.4-bin.zip
 zipStoreBase=GRADLE_USER_HOME
 zipStorePath=wrapper/dists
diff --git a/src/main/groovy/jp/co/soramitsu/devops/docker/DockerPlugin.groovy b/src/main/groovy/jp/co/soramitsu/devops/docker/DockerPlugin.groovy
index f129d1d..622ee70 100644
--- a/src/main/groovy/jp/co/soramitsu/devops/docker/DockerPlugin.groovy
+++ b/src/main/groovy/jp/co/soramitsu/devops/docker/DockerPlugin.groovy
@@ -218,7 +218,7 @@ class DockerPlugin implements Plugin<Project> {
                 // setup tiny https://github.com/krallin/tini
                 t.runCommand "apk add --no-cache tini"
                 t.runCommand "addgroup -S appuser && adduser -S -G appuser appuser"
-            }  else {
+            } else {
                 // setup tiny https://github.com/krallin/tini
                 t.addFile "https://github.com/krallin/tini/releases/download/v0.19.0/tini", "/sbin/tini"
                 t.runCommand "chmod +x /sbin/tini"
@@ -277,6 +277,8 @@ class DockerPlugin implements Plugin<Project> {
                 flags << "-XX:MinRAMPercentage=50"
                 flags << "-XX:InitialRAMPercentage=50"
                 break
+            case 21:
+                break;
             default:
                 throw new IllegalStateException(format("undefined/unsupported java version: ${version}"))
         }
@@ -293,6 +295,8 @@ class DockerPlugin implements Plugin<Project> {
             return 'openjdk:13'
         } else if (javaVersion == 17) {
             return 'openjdk:17-jdk-slim'
+        } else if (javaVersion == 21) {
+            return 'amazoncorretto:21-alpine3.18-jdk'
         } else {
             // default fallback version
             return 'openjdk:8-jre-alpine'
diff --git a/src/test/groovy/jp/co/soramitsu/devops/utils/BaseIntegrationTest.groovy b/src/test/groovy/jp/co/soramitsu/devops/utils/BaseIntegrationTest.groovy
index cce066d..fa63116 100644
--- a/src/test/groovy/jp/co/soramitsu/devops/utils/BaseIntegrationTest.groovy
+++ b/src/test/groovy/jp/co/soramitsu/devops/utils/BaseIntegrationTest.groovy
@@ -8,7 +8,7 @@ import spock.lang.TempDir
 import java.nio.file.Path
 
 class BaseIntegrationTest extends Specification {
-    private static final String defaultGradleVersion = '7.4'
+    private static final String defaultGradleVersion = '8.4'
 
     @TempDir
     Path testProjectDir
diff --git a/src/test/groovy/jp/co/soramitsu/devops/utils/GradleProjectExecutor.groovy b/src/test/groovy/jp/co/soramitsu/devops/utils/GradleProjectExecutor.groovy
index cadbf8a..868dd5b 100644
--- a/src/test/groovy/jp/co/soramitsu/devops/utils/GradleProjectExecutor.groovy
+++ b/src/test/groovy/jp/co/soramitsu/devops/utils/GradleProjectExecutor.groovy
@@ -12,7 +12,7 @@ class GradleProjectExecutor {
 
     Logger logger = LoggerFactory.getLogger(GradleProjectExecutor.class)
 
-    private static final String defaultGradleVersion = '7.4'
+    private static final String defaultGradleVersion = '8.4'
 
     File projectDir
     protected File buildFile