google · gchatelet · Dec 23, 2025 · Dec 20, 2025 · Dec 21, 2025 · Dec 22, 2025
diff --git a/.bazelrc b/.bazelrc
@@ -23,6 +23,10 @@ build --define absl=1
 # Fix the python version
 build --@rules_python//python/config_settings:python_version=3.12
 
+# Fix the Java version
+build --java_language_version=21 # Version of the source files
+build --java_runtime_version=remotejdk_21 # Hermetic JRE
+
 ###############################################################################
 # Per plaform options
 ###############################################################################

diff --git a/.github/workflows/amd64_macos_bazel.yml b/.github/workflows/amd64_macos_bazel.yml
@@ -33,11 +33,11 @@ jobs:
     runs-on: macos-15-intel
     steps:
       - uses: actions/checkout@v6
-      - name: Set Java to OpenJDK 17 (Temurin)
+      - name: Set Java to OpenJDK 21 (Temurin)
         uses: actions/setup-java@v5
         with:
           distribution: 'temurin'
-          java-version: '17'
+          java-version: '21'
       - name: Check mvn
         run: mvn --version
       - name: Setup Python

diff --git a/.github/workflows/amd64_windows_bazel.yml b/.github/workflows/amd64_windows_bazel.yml
@@ -36,7 +36,7 @@ jobs:
       - uses: actions/setup-java@v5
         with:
           distribution: 'temurin'
-          java-version: '17'
+          java-version: '21'
       - name: Check java
         run: java -version
       - name: Check mvn

diff --git a/.github/workflows/arm64_macos_bazel.yml b/.github/workflows/arm64_macos_bazel.yml
@@ -33,11 +33,11 @@ jobs:
     runs-on: macos-latest # macos arm64 based runner
     steps:
       - uses: actions/checkout@v6
-      - name: Set Java to OpenJDK 17 (Temurin)
+      - name: Set Java to OpenJDK 21 (Temurin)
         uses: actions/setup-java@v5
         with:
           distribution: 'temurin'
-          java-version: '17'
+          java-version: '21'
       - name: Check mvn
         run: mvn --version
       - name: Setup Python

diff --git a/.github/workflows/presubmit.yml b/.github/workflows/presubmit.yml
@@ -13,7 +13,7 @@ concurrency:
 env:
   PYTHON_VERSION: '3.12'
   JAVA_DISTRIBUTION: 'temurin'
-  JAVA_VERSION: '17'
+  JAVA_VERSION: '21'
 
 jobs:
 ###############################################################################
@@ -33,10 +33,6 @@ jobs:
     runs-on: ${{matrix.os}}
     steps:
     - uses: actions/checkout@v6
-    - uses: actions/setup-java@v5
-      with:
-        distribution: ${{env.JAVA_DISTRIBUTION}}
-        java-version: ${{env.JAVA_VERSION}}
     - uses: actions/setup-python@v6
       with:
         python-version: ${{env.PYTHON_VERSION}}

diff --git a/bazel/docker/fedora/Dockerfile b/bazel/docker/fedora/Dockerfile
@@ -36,7 +36,7 @@ COPY . .
 
 FROM devel AS build
 RUN bazel version
-RUN bazel build --java_runtime_version=remotejdk_21 --config=ci //ortools/... //examples/...
+RUN bazel build --config=ci //ortools/... //examples/...
 
 FROM build AS test
-RUN bazel test --java_runtime_version=remotejdk_21 --config=ci //ortools/... //examples/...
+RUN bazel test --config=ci //ortools/... //examples/...
diff --git a/bazel/docker/opensuse/Dockerfile b/bazel/docker/opensuse/Dockerfile
@@ -18,7 +18,7 @@ https://github.com/bazelbuild/bazelisk/releases/download/v1.27.0/bazelisk-linux-
 
 # Install Java JDK and Maven
 RUN zypper refresh \
-&& zypper install -y java-17-openjdk-devel maven \
+&& zypper install -y java-21-openjdk-devel maven \
 && zypper clean -a
 ENV PATH=/usr/share/maven/bin:$PATH
 

diff --git a/bazel/docker/rockylinux/Dockerfile b/bazel/docker/rockylinux/Dockerfile
@@ -22,7 +22,7 @@ https://github.com/bazelbuild/bazelisk/releases/download/v1.27.0/bazelisk-linux-
 
 # Install Java
 RUN dnf -y update \
-&& dnf -y install java-11-openjdk java-11-openjdk-devel maven \
+&& dnf -y install java-21-openjdk java-21-openjdk-devel maven \
 && dnf clean all
 ENV JAVA_HOME=/usr/lib/jvm/java-openjdk
 

diff --git a/cmake/docker/alpine/java.Dockerfile b/cmake/docker/alpine/java.Dockerfile
@@ -1,7 +1,7 @@
 FROM ortools/cmake:alpine_swig AS env
 
-ENV JAVA_HOME=/usr/lib/jvm/java-1.8-openjdk
-RUN apk add --no-cache openjdk8 maven
+ENV JAVA_HOME=/usr/lib/jvm/java-21-openjdk
+RUN apk add --no-cache openjdk21 maven
 
 FROM env AS devel
 WORKDIR /home/project

diff --git a/cmake/docker/opensuse/java.Dockerfile b/cmake/docker/opensuse/java.Dockerfile
@@ -2,7 +2,7 @@ FROM ortools/cmake:opensuse_swig AS env
 
 # Install Java JDK and Maven
 RUN zypper refresh \
-&& zypper install -y java-17-openjdk-devel maven \
+&& zypper install -y java-21-openjdk-devel maven \
 && zypper clean -a
 ENV PATH=/usr/share/maven/bin:$PATH
 

diff --git a/cmake/docker/rockylinux/java.Dockerfile b/cmake/docker/rockylinux/java.Dockerfile
@@ -1,11 +1,11 @@
 FROM ortools/cmake:rockylinux_swig AS env
 
 RUN dnf -y update \
-&& dnf -y install java-11-openjdk java-11-openjdk-devel maven \
+&& dnf -y install java-21-openjdk java-21-openjdk-devel maven \
 && dnf clean all \
 && rm -rf /var/cache/dnf
-RUN alternatives --set java /usr/lib/jvm/java-11-openjdk-11.*.x86_64/bin/java
-ENV JAVA_HOME=/usr/lib/jvm/java-11-openjdk
+RUN alternatives --set java /usr/lib/jvm/java-21-openjdk-21.*.x86_64/bin/java
+ENV JAVA_HOME=/usr/lib/jvm/java-21-openjdk
 
 FROM env AS devel
 WORKDIR /home/project

diff --git a/cmake/java.cmake b/cmake/java.cmake
@@ -35,7 +35,7 @@ endif()
 list(APPEND CMAKE_SWIG_FLAGS "-DOR_DLL=")
 
 # Find Java and JNI
-find_package(Java 1.8 COMPONENTS Development REQUIRED)
+find_package(Java 21 COMPONENTS Development REQUIRED)
 find_package(JNI REQUIRED)
 
 # Find maven

diff --git a/cmake/samples/java/pom.xml b/cmake/samples/java/pom.xml
@@ -14,8 +14,8 @@
 
   <properties>
     <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
-    <maven.compiler.source>1.8</maven.compiler.source>
-    <maven.compiler.target>1.8</maven.compiler.target>
+    <maven.compiler.source>21</maven.compiler.source>
+    <maven.compiler.target>21</maven.compiler.target>
   </properties>
 
   <dependencies>

diff --git a/tools/docker/Makefile b/tools/docker/Makefile
@@ -118,7 +118,7 @@ help:
 	@echo -e "\t${BOLD}<lang>${RESET}: Language to build"
 	@echo -e "\t\t${BOLD}cpp${RESET} C++"
 	@echo -e "\t\t${BOLD}dotnet${RESET} .Net 8.0 wrappers"
-	@echo -e "\t\t${BOLD}java${RESET} Java (JDK 8.0) wrappers"
+	@echo -e "\t\t${BOLD}java${RESET} Java (JDK 21) wrappers"
 	@echo -e "\t\t${BOLD}python${RESET} Python 3.9+ wrappers"
 	@echo
 	@echo -e "\te.g. 'make sh_amd64_ubuntu-22.04_cpp_build'"

diff --git a/tools/docker/images/almalinux-9.Dockerfile b/tools/docker/images/almalinux-9.Dockerfile
@@ -38,7 +38,7 @@ RUN dotnet --info
 
 # Install Java 8 SDK
 RUN dnf -y update \
-&& dnf -y install java-1.8.0-openjdk java-1.8.0-openjdk-devel maven \
+&& dnf -y install java-21-openjdk java-21-openjdk-devel maven \
 && dnf clean all \
 && rm -rf /var/cache/dnf
 

diff --git a/tools/docker/images/alpine-edge.Dockerfile b/tools/docker/images/alpine-edge.Dockerfile
@@ -19,8 +19,8 @@ RUN apk add --no-cache dotnet8-sdk
 RUN dotnet --info
 
 # Install Java
-ENV JAVA_HOME=/usr/lib/jvm/java-1.8-openjdk
-RUN apk add --no-cache openjdk8 maven
+ENV JAVA_HOME=/usr/lib/jvm/java-21-openjdk
+RUN apk add --no-cache openjdk-21-jdk maven
 
 # Install Python
 RUN apk add --no-cache python3-dev py3-pip py3-wheel \

diff --git a/tools/docker/images/fedora-40.Dockerfile b/tools/docker/images/fedora-40.Dockerfile
@@ -28,7 +28,7 @@ RUN dotnet --info
 
 # Install Java
 RUN dnf -y update \
-&& dnf -y install java-11-openjdk java-11-openjdk-devel maven \
+&& dnf -y install java-21-openjdk java-21-openjdk-devel maven \
 && dnf clean all
 ENV JAVA_HOME=/usr/lib/jvm/java-openjdk
 

diff --git a/tools/docker/images/fedora-41.Dockerfile b/tools/docker/images/fedora-41.Dockerfile
@@ -30,7 +30,7 @@ RUN dotnet --info
 
 # Install Java
 RUN dnf -y update \
-&& dnf -y install java-11-openjdk java-11-openjdk-devel maven \
+&& dnf -y install java-21-openjdk java-21-openjdk-devel maven \
 && dnf clean all
 ENV JAVA_HOME=/usr/lib/jvm/java-openjdk
 

diff --git a/tools/docker/images/opensuse-leap.Dockerfile b/tools/docker/images/opensuse-leap.Dockerfile
@@ -29,8 +29,8 @@ RUN wget -q "https://dot.net/v1/dotnet-install.sh" \
 # Trigger first run experience by running arbitrary cmd
 RUN dotnet --info
 
-# Install Java (openjdk-8)
-RUN zypper install -y java-1_8_0-openjdk java-1_8_0-openjdk-devel maven \
+# Install Java (openjdk-21)
+RUN zypper install -y java-21-openjdk java-21-openjdk-devel maven \
 && zypper clean -a
 
 # Install Python

diff --git a/tools/docker/images/rockylinux-9.Dockerfile b/tools/docker/images/rockylinux-9.Dockerfile
@@ -38,7 +38,7 @@ RUN dotnet --info
 
 # Install Java 8 SDK
 RUN dnf -y update \
-&& dnf -y install java-1.8.0-openjdk java-1.8.0-openjdk-devel maven \
+&& dnf -y install java-21-openjdk java-21-openjdk-devel maven \
 && dnf clean all \
 && rm -rf /var/cache/dnf
 

diff --git a/tools/docker/images/ubuntu-20.04.Dockerfile b/tools/docker/images/ubuntu-20.04.Dockerfile
@@ -39,12 +39,12 @@ RUN apt-get update -qq \
 # Trigger first run experience by running arbitrary cmd
 RUN dotnet --info
 
-# Install Java (openjdk-11)
+# Install Java (openjdk-21-jdk)
 RUN apt-get update -qq \
-&& apt-get install -yq default-jdk maven \
+&& apt-get install -yq openjdk-21-jdk maven \
 && apt-get clean \
 && rm -rf /var/lib/apt/lists/* /tmp/* /var/tmp/*
-ENV JAVA_HOME=/usr/lib/jvm/default-java
+ENV JAVA_HOME=/usr/lib/jvm/java-21-openjdk
 
 # Install Python
 RUN apt-get update -qq \

diff --git a/tools/docker/images/ubuntu-22.04.Dockerfile b/tools/docker/images/ubuntu-22.04.Dockerfile
@@ -37,12 +37,12 @@ RUN apt-get update -qq \
 # Trigger first run experience by running arbitrary cmd
 RUN dotnet --info
 
-# Install Java (openjdk-11)
+# Install Java (openjdk-21-jdk)
 RUN apt-get update -qq \
-&& apt-get install -yq default-jdk maven \
+&& apt-get install -yq openjdk-21-jdk maven \
 && apt-get clean \
 && rm -rf /var/lib/apt/lists/* /tmp/* /var/tmp/*
-ENV JAVA_HOME=/usr/lib/jvm/default-java
+ENV JAVA_HOME=/usr/lib/jvm/java-21-openjdk
 
 # Install Python
 RUN apt-get update -qq \

diff --git a/tools/docker/images/ubuntu-24.04.Dockerfile b/tools/docker/images/ubuntu-24.04.Dockerfile
@@ -29,12 +29,12 @@ RUN apt-get update -qq \
 # Trigger first run experience by running arbitrary cmd
 RUN dotnet --info
 
-# Install Java (openjdk-11)
+# Install Java (openjdk-21-jdk)
 RUN apt-get update -qq \
-&& apt-get install -yq default-jdk maven \
+&& apt-get install -yq openjdk-21-jdk maven \
 && apt-get clean \
 && rm -rf /var/lib/apt/lists/* /tmp/* /var/tmp/*
-ENV JAVA_HOME=/usr/lib/jvm/default-java
+ENV JAVA_HOME=/usr/lib/jvm/java-21-openjdk
 
 # Install Python
 RUN apt-get update -qq \

diff --git a/tools/docker/images/ubuntu-24.10.Dockerfile b/tools/docker/images/ubuntu-24.10.Dockerfile
@@ -29,12 +29,12 @@ RUN apt-get update -qq \
 # Trigger first run experience by running arbitrary cmd
 RUN dotnet --info
 
-# Install Java (openjdk-11)
+# Install Java (openjdk-21-jdk)
 RUN apt-get update -qq \
-&& apt-get install -yq default-jdk maven \
+&& apt-get install -yq openjdk-21-jdk maven \
 && apt-get clean \
 && rm -rf /var/lib/apt/lists/* /tmp/* /var/tmp/*
-ENV JAVA_HOME=/usr/lib/jvm/default-java
+ENV JAVA_HOME=/usr/lib/jvm/java-21-openjdk
 
 # Install Python
 RUN apt-get update -qq \

diff --git a/tools/docker/test/almalinux-9/java.Dockerfile b/tools/docker/test/almalinux-9/java.Dockerfile
@@ -13,7 +13,7 @@ RUN dnf -y update \
 
 # Install Java 8 SDK
 RUN dnf -y update \
-&& dnf -y install java-1.8.0-openjdk java-1.8.0-openjdk-devel maven \
+&& dnf -y install java-21-openjdk java-21-openjdk-devel maven \
 && dnf clean all \
 && rm -rf /var/cache/dnf
 #ENV JAVA_HOME=/usr/lib/jvm/java

diff --git a/tools/docker/test/alpine-edge/java.Dockerfile b/tools/docker/test/alpine-edge/java.Dockerfile
@@ -11,8 +11,8 @@ ENTRYPOINT ["/bin/sh", "-c"]
 CMD ["/bin/sh"]
 
 # Install Java
-ENV JAVA_HOME=/usr/lib/jvm/java-1.8-openjdk
-RUN apk add --no-cache openjdk8 maven
+ENV JAVA_HOME=/usr/lib/jvm/java-21-openjdk
+RUN apk add --no-cache openjdk-21-jdk maven
 
 WORKDIR /root
 ADD or-tools_amd64_alpine-edge_java_v*.tar.gz .

diff --git a/tools/docker/test/fedora-40/java.Dockerfile b/tools/docker/test/fedora-40/java.Dockerfile
@@ -10,7 +10,7 @@ RUN dnf -y update \
 
 # Java Install
 RUN dnf -y update \
-&& dnf -y install java-11-openjdk java-11-openjdk-devel maven \
+&& dnf -y install java-21-openjdk java-21-openjdk-devel maven \
 && dnf clean all
 ENV JAVA_HOME=/usr/lib/jvm/java-openjdk
 

diff --git a/tools/docker/test/fedora-41/java.Dockerfile b/tools/docker/test/fedora-41/java.Dockerfile
@@ -10,7 +10,7 @@ RUN dnf -y update \
 
 # Java Install
 RUN dnf -y update \
-&& dnf -y install java-11-openjdk java-11-openjdk-devel maven \
+&& dnf -y install java-21-openjdk java-21-openjdk-devel maven \
 && dnf clean all
 ENV JAVA_HOME=/usr/lib/jvm/java-openjdk
 

diff --git a/tools/docker/test/opensuse-leap/java.Dockerfile b/tools/docker/test/opensuse-leap/java.Dockerfile
@@ -13,7 +13,7 @@ ENTRYPOINT ["/usr/bin/bash", "-c"]
 CMD ["/usr/bin/bash"]
 
 # Java install (openjdk-8)
-RUN zypper install -y java-1_8_0-openjdk java-1_8_0-openjdk-devel maven \
+RUN zypper install -y java-21-openjdk java-21-openjdk-devel maven \
 && zypper clean -a
 
 WORKDIR /root

diff --git a/tools/docker/test/rockylinux-9/java.Dockerfile b/tools/docker/test/rockylinux-9/java.Dockerfile
@@ -13,7 +13,7 @@ RUN dnf -y update \
 
 # Install Java 8 SDK
 RUN dnf -y update \
-&& dnf -y install java-1.8.0-openjdk java-1.8.0-openjdk-devel maven \
+&& dnf -y install java-21-openjdk java-21-openjdk-devel maven \
 && dnf clean all \
 && rm -rf /var/cache/dnf
 #ENV JAVA_HOME=/usr/lib/jvm/java

diff --git a/tools/docker/test/ubuntu-20.04/java.Dockerfile b/tools/docker/test/ubuntu-20.04/java.Dockerfile
@@ -3,10 +3,10 @@ FROM ubuntu:20.04
 
 ENV DEBIAN_FRONTEND=noninteractive
 RUN apt-get update -qq \
-&& apt-get install -yq build-essential zlib1g-dev default-jdk maven \
+&& apt-get install -yq build-essential zlib1g-dev openjdk-21-jdk maven \
 && apt-get clean \
 && rm -rf /var/lib/apt/lists/* /tmp/* /var/tmp/*
-ENV JAVA_HOME=/usr/lib/jvm/default-java
+ENV JAVA_HOME=/usr/lib/jvm/java-openjdk
 
 #ENV TZ=America/Los_Angeles
 #RUN ln -snf /usr/share/zoneinfo/$TZ /etc/localtime && echo $TZ > /etc/timezone

diff --git a/tools/docker/test/ubuntu-22.04/java.Dockerfile b/tools/docker/test/ubuntu-22.04/java.Dockerfile
@@ -9,11 +9,10 @@ RUN apt-get update -qq \
 
 # Java/Maven Install
 RUN apt-get update -qq \
-&& DEBIAN_FRONTEND=noninteractive apt-get install -yq \
- default-jdk maven \
+&& DEBIAN_FRONTEND=noninteractive apt-get install -yq openjdk-21-jdk maven \
 && apt-get clean \
 && rm -rf /var/lib/apt/lists/* /tmp/* /var/tmp/*
-ENV JAVA_HOME=/usr/lib/jvm/default-java
+ENV JAVA_HOME=/usr/lib/jvm/java-openjdk
 
 WORKDIR /root
 ADD or-tools_amd64_ubuntu-22.04_java_v*.tar.gz .

diff --git a/tools/docker/test/ubuntu-24.04/java.Dockerfile b/tools/docker/test/ubuntu-24.04/java.Dockerfile
@@ -9,11 +9,10 @@ RUN apt-get update -qq \
 
 # Java/Maven Install
 RUN apt-get update -qq \
-&& DEBIAN_FRONTEND=noninteractive apt-get install -yq \
- default-jdk maven \
+&& DEBIAN_FRONTEND=noninteractive apt-get install -yq openjdk-21-jdk maven \
 && apt-get clean \
 && rm -rf /var/lib/apt/lists/* /tmp/* /var/tmp/*
-ENV JAVA_HOME=/usr/lib/jvm/default-java
+ENV JAVA_HOME=/usr/lib/jvm/java-openjdk
 
 WORKDIR /root
 ADD or-tools_amd64_ubuntu-24.04_java_v*.tar.gz .

diff --git a/tools/docker/test/ubuntu-24.10/java.Dockerfile b/tools/docker/test/ubuntu-24.10/java.Dockerfile
@@ -9,11 +9,10 @@ RUN apt-get update -qq \
 
 # Java/Maven Install
 RUN apt-get update -qq \
-&& DEBIAN_FRONTEND=noninteractive apt-get install -yq \
- default-jdk maven \
+&& DEBIAN_FRONTEND=noninteractive apt-get install -yq openjdk-21-jdk maven \
 && apt-get clean \
 && rm -rf /var/lib/apt/lists/* /tmp/* /var/tmp/*
-ENV JAVA_HOME=/usr/lib/jvm/default-java
+ENV JAVA_HOME=/usr/lib/jvm/java-openjdk
 
 WORKDIR /root
 ADD or-tools_amd64_ubuntu-24.10_java_v*.tar.gz .