chore: drop support for java 8.

.github/RELEASE_TEMPLATE.md

@@ -25,7 +25,7 @@ conda install -c conda-forge neqsim=<version>
 Requirements:
 
 - Python 3.9 or newer.
-- Java 8 or newer for pip installs.
+- Java 11 or newer for pip installs.
 - Conda installs include OpenJDK through conda-forge.
 
 Verify the installed package version without starting the JVM:

.github/workflows/generate-stubs.yml

@@ -4,7 +4,7 @@ on:
   # Run when JAR files are updated
   push:
     paths:
-      - 'src/neqsim/lib/**/*.jar'
+      - 'src/neqsim/lib/*.jar'
   # Run on release
   release:
     types: [published]
@@ -16,18 +16,18 @@ jobs:
     runs-on: ubuntu-latest
 
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v7
 
       - name: Set up Python
-        uses: actions/setup-python@v5
+        uses: actions/setup-python@v6
         with:
-          python-version: '3.11'
+          python-version: '3.13'
 
       - name: Set up Java
-        uses: actions/setup-java@v4
+        uses: actions/setup-java@v5
         with:
           distribution: 'temurin'
-          java-version: '17'
+          java-version: '21'
 
       - name: Install dependencies
         run: |
@@ -39,7 +39,7 @@ jobs:
           poetry run python scripts/generate_stubs.py
 
       - name: Commit updated stubs
-        uses: stefanzweifel/git-auto-commit-action@v5
+        uses: stefanzweifel/git-auto-commit-action@v7
         with:
           commit_message: "chore: regenerate Java stubs"
           file_pattern: "src/jneqsim-stubs/**"

.github/workflows/pre-commit.yaml

@@ -10,10 +10,10 @@ jobs:
   main:
     runs-on: ubuntu-latest
     steps:
-    - uses: actions/checkout@v4
-    - uses: actions/setup-python@v5
+    - uses: actions/checkout@v7
+    - uses: actions/setup-python@v6
       with:
-        python-version: "3.12"
+        python-version: "3.13"
     - uses: pre-commit/action@v3.0.1
     - uses: pre-commit-ci/lite-action@v1.1.0
       if: always()

.github/workflows/publish-to-test-pypi.yml

@@ -14,15 +14,15 @@ jobs:
       id-token: write
       contents: read
     steps:
-    - uses: actions/checkout@v4
+    - uses: actions/checkout@v7
 
     - name: Install poetry
       run: pipx install poetry
 
     - name: Setup python
-      uses: actions/setup-python@v5
+      uses: actions/setup-python@v6
       with:
-        python-version: 3.11
+        python-version: 3.13
 
     - name: Install dependencies
       run: poetry install --no-interaction

.github/workflows/runtests.yml

@@ -14,13 +14,13 @@ jobs:
         version: [3.9, 3.12, 3.13]
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v7
 
       - name: Install poetry
         run: pipx install poetry
 
       - name: Setup Python
-        uses: actions/setup-python@v5
+        uses: actions/setup-python@v6
         with:
           python-version: ${{ matrix.version }}
 

README.md

@@ -46,7 +46,7 @@ It provides Python toolboxes such as [thermoTools](https://github.com/equinor/ne
 ### Install
 
 <table>
-<tr><td><strong>pip</strong> (requires Java 8+)</td><td><strong>conda</strong> (Java included)</td></tr>
+<tr><td><strong>pip</strong> (requires Java 11+)</td><td><strong>conda</strong> (Java included)</td></tr>
 <tr>
 <td>
 
@@ -65,7 +65,7 @@ conda install -c conda-forge neqsim
 </tr>
 </table>
 
-> **Prerequisites:** Python 3.9+ and Java 8+. The conda package automatically installs OpenJDK — no separate Java setup needed. For pip, install Java from [Adoptium](https://adoptium.net/).
+> **Prerequisites:** Python 3.9+ and Java 11+. The conda package automatically installs OpenJDK — no separate Java setup needed. For pip, install Java from [Adoptium](https://adoptium.net/).
 
 ### Try it now
 

docs/release-notes/v3.10.0.md

@@ -57,4 +57,4 @@ printFrame(natural_gas)
 - Documentation: https://equinor.github.io/neqsimhome/
 - Python examples: https://github.com/equinor/neqsim-python/tree/master/examples
 - Java engine: https://github.com/equinor/neqsim
-- Discussions: https://github.com/equinor/neqsim/discussions
+- Discussions: https://github.com/equinor/neqsim/discussions

docs/release-notes/v3.11.0.md

@@ -57,4 +57,4 @@ printFrame(natural_gas)
 - Documentation: https://equinor.github.io/neqsimhome/
 - Python examples: https://github.com/equinor/neqsim-python/tree/master/examples
 - Java engine: https://github.com/equinor/neqsim
-- Discussions: https://github.com/equinor/neqsim/discussions
+- Discussions: https://github.com/equinor/neqsim/discussions

examples/equationOfState.py

@@ -212,7 +212,8 @@ def create_wet_gas(eos_name):
 # =============================================================================
 print("\n6. EOS-CG FOR CO2 AND COMBUSTION GASES")
 print("-" * 40)
-print("""
+print(
+    """
 EOS-CG (Equation of State for Combustion Gases) is based on GERG-2008
 but optimized for CO2-rich mixtures and combustion product gases.
 
@@ -224,7 +225,8 @@ def create_wet_gas(eos_name):
   - Blue/green hydrogen with CO2
 
 Components: CO2, N2, O2, Ar, H2O, CO, H2, H2S, SO2, CH4
-""")
+"""
+)
 
 # Create a typical flue gas / CCS mixture
 print("Example: CO2-rich CCS mixture")
@@ -261,7 +263,8 @@ def create_wet_gas(eos_name):
 # =============================================================================
 print("\n7. GUIDELINES FOR EoS SELECTION")
 print("-" * 40)
-print("""
+print(
+    """
 Application                          | Recommended EoS
 -------------------------------------|----------------------
 Natural gas properties               | GERG-2008 (most accurate)
@@ -286,5 +289,6 @@ def create_wet_gas(eos_name):
 Gas hydrates                         | CPA with hydrate model
                                      |
 Electrolyte solutions (brine)        | Electrolyte-CPA
-""")
+"""
+)
 print("=" * 70)

examples/flashCalculations.py

@@ -189,7 +189,8 @@
 print("\n" + "=" * 70)
 print("FLASH CALCULATION SUMMARY")
 print("=" * 70)
-print("""
+print(
+    """
 Flash Type | Given          | Find           | Application
 -----------|----------------|----------------|---------------------------
 TPflash    | T, P           | Phases, comp.  | General equilibrium
@@ -198,5 +199,6 @@
 TVflash    | T, V           | P, phases      | Closed vessels
 VHflash    | V, H           | T, P, phases   | Adiabatic closed systems
 VUflash    | V, U           | T, P, phases   | Isolated systems
-""")
+"""
+)
 print("=" * 70)

examples/fluidCreation.py

@@ -272,7 +272,8 @@
 # =============================================================================
 print("\n9. COMMONLY USED COMPONENTS")
 print("-" * 40)
-print("""
+print(
+    """
 Category           | Component Names
 -------------------|------------------------------------------------
 Light gases        | nitrogen, oxygen, argon, helium, hydrogen, H2S
@@ -287,7 +288,8 @@
 
 Note: For components not in database, use addTBPfraction() or
       addPlusFraction() with MW and density.
-""")
+"""
+)
 
 # =============================================================================
 # 10. ELECTROLYTE FLUIDS

examples/hydrateCalculations.py

@@ -31,7 +31,8 @@
 # =============================================================================
 print("\n1. INTRODUCTION TO GAS HYDRATES")
 print("-" * 40)
-print("""
+print(
+    """
 Gas hydrates form when water and light gases (C1, C2, C3, CO2, H2S)
 combine under high pressure and low temperature conditions.
 
@@ -43,7 +44,8 @@
   - Temperature: Typically < 25°C
   - Pressure: Typically > 10-20 bara
   - Presence of free water
-""")
+"""
+)
 
 # =============================================================================
 # 2. HYDRATE FORMATION TEMPERATURE
@@ -114,14 +116,16 @@
 # =============================================================================
 print("\n4. SUBCOOLING - HYDRATE RISK ASSESSMENT")
 print("-" * 40)
-print("""
+print(
+    """
 Subcooling (ΔT) = Hydrate formation T - Operating T
 
 Interpretation:
   ΔT > 0: Operating BELOW hydrate T → HIGH RISK
   ΔT = 0: At hydrate equilibrium → BORDERLINE
   ΔT < 0: Operating ABOVE hydrate T → SAFE
-""")
+"""
+)
 
 # Example calculation
 gas.setPressure(100.0, "bara")
@@ -224,7 +228,8 @@
 # =============================================================================
 print("\n7. INHIBITOR SELECTION GUIDELINES")
 print("-" * 40)
-print("""
+print(
+    """
 ┌─────────────────────────────────────────────────────────────────┐
 │ Inhibitor Comparison                                            │
 ├────────────┬──────────────────────────────────────────────────┐
@@ -251,14 +256,16 @@
 │            │ ✗ Cannot be regenerated                         │
 │            │ → Best for: Drilling fluids, completion ops     │
 └────────────┴──────────────────────────────────────────────────┘
-""")
+"""
+)
 
 # =============================================================================
 # 8. KINETIC HYDRATE INHIBITORS (KHI)
 # =============================================================================
 print("\n8. KINETIC HYDRATE INHIBITORS (KHI)")
 print("-" * 40)
-print("""
+print(
+    """
 Unlike thermodynamic inhibitors (MEG, MeOH) that shift equilibrium,
 KHIs work by slowing hydrate formation kinetics.
 
@@ -273,22 +280,25 @@
 
 Note: NeqSim primarily calculates thermodynamic equilibrium.
       KHI effects require separate kinetic models.
-""")
+"""
+)
 
 # =============================================================================
 # 9. PRACTICAL EXAMPLE: PIPELINE HYDRATE ASSESSMENT
 # =============================================================================
 print("\n9. PRACTICAL EXAMPLE: PIPELINE HYDRATE ASSESSMENT")
 print("-" * 40)
 
-print("""
+print(
+    """
 Scenario: Subsea pipeline from wellhead to platform
   - Wellhead: 150 bara, 80°C
   - Pipeline arrival: 80 bara, 5°C
   - Gas is water-saturated
 
 Question: Will hydrates form? How much MEG is needed?
-""")
+"""
+)
 
 # Check hydrate risk
 pipeline_gas = fluid("cpa")