Update to JDK21 - both JDK and language level

.devcontainer/devcontainer.json

@@ -31,9 +31,9 @@
         // Install java.
         // See https://github.com/devcontainers/features/tree/main/src/java#options for details.
         "ghcr.io/devcontainers/features/java:1": {
-            "version": "20.0.2-tem",
+            "version": "21.0.1-librca",
             "installGradle": false,
-            "jdkDistro": "tem"
+            "jdkDistro": "librca"
         }
     }
 }

.github/workflows/deployment-arm64.yml

@@ -61,23 +61,9 @@ jobs:
       - name: Setup JDK
         uses: actions/setup-java@v3
         with:
-          java-version: 20
-          distribution: 'temurin'
+          java-version: 21.0.1
+          distribution: 'liberica'
           cache: 'gradle'
-      - name: Setup JDK jabref-fix macOS
-        shell: bash
-        run: |
-            mkdir ${{runner.temp}}/jdk
-            wget -qO- https://files.jabref.org/jdks/jdk-macos-aarch64.tar.gz | tar xz -C ${{runner.temp}}/jdk
-            mv ${{runner.temp}}/jdk/jdk-21.jdk ${{runner.temp}}/jdk/jdk-21
-            echo "JDK21=${{runner.temp}}/jdk/jdk-21" >> "$GITHUB_ENV"
-            ls ${{runner.temp}}/jdk
-
-            echo "org.gradle.java.installations.paths=${{runner.temp}}/jdk/jdk-21" >> gradle.properties
-            echo "org.gradle.java.installations.auto-detect=false" >> gradle.properties
-            cat gradle.properties
-
-            sed -i'.bak' -e "s/JavaLanguageVersion.of(20)/JavaLanguageVersion.of(21)/" build.gradle
       - name: Clean up keychain
         run: |
          security delete-keychain signing_temp.keychain ${{runner.temp}}/keychain/notarization.keychain || true
@@ -104,9 +90,9 @@ jobs:
       - name: Build dmg (macOS)
         shell: bash
         run: |
-          ${{env.JDK21}}/Contents/Home/bin/jpackage \
+          jpackage \
           --module org.jabref/org.jabref.cli.Launcher \
-          --module-path ${{env.JDK21}}/Contents/Home/jmods/:build/jlinkbase/jlinkjars \
+          --module-path ${{env.JAVA_HOME}}/jmods/:build/jlinkbase/jlinkjars \
           --add-modules org.jabref,org.jabref.merged.module  \
           --dest build/distribution \
           --app-content buildres/mac/jabrefHost.py \
@@ -128,9 +114,9 @@ jobs:
       - name: Build pkg (macOS)
         shell: bash
         run: |
-          ${{env.JDK21}}/Contents/Home/bin/jpackage \
+          jpackage \
           --module org.jabref/org.jabref.cli.Launcher \
-          --module-path ${{env.JDK21}}/Contents/Home/jmods/:build/jlinkbase/jlinkjars \
+          --module-path ${{env.JAVA_HOME}}/jmods/:build/jlinkbase/jlinkjars \
           --add-modules org.jabref,org.jabref.merged.module  \
           --dest build/distribution \
           --app-content buildres/mac/jabrefHost.py \

.github/workflows/deployment.yml

@@ -92,52 +92,9 @@ jobs:
       - name: Setup JDK
         uses: actions/setup-java@v3
         with:
-          java-version: 20
-          distribution: 'temurin'
+          java-version: 21.0.1
+          distribution: 'liberica'
           cache: 'gradle'
-      - name: Setup JDK jabref-fix (Windows)
-        if: (matrix.os == 'windows-latest')
-        shell: bash
-        run: |
-         mkdir ${{runner.temp}}\jdk
-         curl -kLsS ${{matrix.eaJDK}} -o temp.zip && 7z x temp.zip -o"$(cygpath -u "$RUNNER_TEMP\jdk")"
-         echo "JDK21=${{runner.temp}}\jdk\jdk-21" >> "$GITHUB_ENV"
-         ls "$(cygpath -u "$RUNNER_TEMP\jdk\jdk-21")"
-
-         echo "org.gradle.java.installations.paths=${{runner.temp}}\jdk\jdk-21" | sed "s/\\\\/\\\\\\\\/g" >> gradle.properties
-         echo "org.gradle.java.installations.auto-detect=false" >> gradle.properties
-         cat gradle.properties
-
-         sed -i "s/JavaLanguageVersion.of(20)/JavaLanguageVersion.of(21)/" build.gradle
-      - name: Setup JDK jabref-fix (linux)
-        if: (matrix.os == 'ubuntu-latest')
-        shell: bash
-        run: |
-          mkdir ${{runner.temp}}/jdk
-          wget -qO- ${{matrix.eaJDK}} | tar xz -C ${{runner.temp}}/jdk
-          echo "JDK21=${{runner.temp}}/jdk/jdk-21" >> "$GITHUB_ENV"
-          ls ${{runner.temp}}/jdk
-
-          echo "org.gradle.java.installations.paths=${{runner.temp}}/jdk/jdk-21" >> gradle.properties
-          echo "org.gradle.java.installations.auto-detect=false" >> gradle.properties
-          cat gradle.properties
-
-          sed -i "s/JavaLanguageVersion.of(20)/JavaLanguageVersion.of(21)/" build.gradle
-      - name: Setup JDK jabref-fix (macOS)
-        if: (matrix.os == 'macos-latest')
-        shell: bash
-        run: |
-          mkdir ${{runner.temp}}/jdk
-          wget -qO- ${{matrix.eaJDK}} | tar xz -C ${{runner.temp}}/jdk
-          mv ${{runner.temp}}/jdk/jdk-21.jdk ${{runner.temp}}/jdk/jdk-21
-          echo "JDK21=${{runner.temp}}/jdk/jdk-21" >> "$GITHUB_ENV"
-          ls ${{runner.temp}}/jdk
-
-          echo "org.gradle.java.installations.paths=${{runner.temp}}/jdk/jdk-21" >> gradle.properties
-          echo "org.gradle.java.installations.auto-detect=false" >> gradle.properties
-          cat gradle.properties
-
-          sed -i'.bak' -e "s/JavaLanguageVersion.of(20)/JavaLanguageVersion.of(21)/" build.gradle
       - name: Prepare merged jars and modules dir (macOS)
         if: (matrix.os == 'macos-latest') || (steps.checksecrets.outputs.secretspresent == 'NO')
         run: ./gradlew -i -PprojVersion="${{ steps.gitversion.outputs.AssemblySemVer }}" -PprojVersionInfo="${{ steps.gitversion.outputs.InformationalVersion }}" prepareModulesDir
@@ -160,9 +117,9 @@ jobs:
         if: (matrix.os == 'macos-latest') && (steps.checksecrets.outputs.secretspresent == 'YES')
         shell: bash
         run: |
-          ${{env.JDK21}}/Contents/Home/bin/jpackage \
+          jpackage \
           --module org.jabref/org.jabref.cli.Launcher \
-          --module-path ${{env.JDK21}}/Contents/Home/jmods/:build/jlinkbase/jlinkjars \
+          --module-path ${{env.JAVA_HOME}}/jmods/:build/jlinkbase/jlinkjars \
           --add-modules org.jabref,org.jabref.merged.module  \
           --dest build/distribution \
           --app-content buildres/mac/jabrefHost.py \
@@ -185,9 +142,9 @@ jobs:
         if: (matrix.os == 'macos-latest') && (steps.checksecrets.outputs.secretspresent == 'YES')
         shell: bash
         run: |
-          ${{env.JDK21}}/Contents/Home/bin/jpackage \
+          jpackage \
           --module org.jabref/org.jabref.cli.Launcher \
-          --module-path ${{env.JDK21}}/Contents/Home/jmods/:build/jlinkbase/jlinkjars \
+          --module-path ${{env.JAVA_HOME}}/jmods/:build/jlinkbase/jlinkjars \
           --add-modules org.jabref,org.jabref.merged.module  \
           --dest build/distribution \
           --app-content buildres/mac/jabrefHost.py \

.github/workflows/refresh-journal-lists.yml

@@ -30,8 +30,8 @@ jobs:
       - name: Set up JDK
         uses: actions/setup-java@v3
         with:
-          java-version: 20
-          distribution: 'temurin'
+          java-version: 21.0.1
+          distribution: 'liberica'
           cache: 'gradle'
       - name: Check whether journal-list.mv can be generated (the "real" generation is done inside JabRef's build process)
         run: |

.github/workflows/tests-fetchers.yml

@@ -48,8 +48,8 @@ jobs:
       - name: Set up JDK
         uses: actions/setup-java@v3
         with:
-          java-version: 20
-          distribution: 'temurin'
+          java-version: 21.0.1
+          distribution: 'liberica'
           cache: 'gradle'
       - name: Run fetcher tests
         run: ./gradlew fetcherTest

.github/workflows/tests.yml

@@ -29,13 +29,13 @@ jobs:
       - name: Checkout source
         uses: actions/checkout@v4
         with:
-          submodules: 'false'
+          submodules: 'true'
           show-progress: 'false'
       - name: Set up JDK
         uses: actions/setup-java@v3
         with:
-          java-version: 20
-          distribution: 'temurin'
+          java-version: 21.0.1
+          distribution: 'liberica'
           cache: 'gradle'
       - name: Run checkstyle reporter
         uses: nikitasavinov/checkstyle-action@master
@@ -103,8 +103,8 @@ jobs:
       - name: Set up JDK
         uses: actions/setup-java@v3
         with:
-          java-version: 20
-          distribution: 'temurin'
+          java-version: 21.0.1
+          distribution: 'liberica'
           cache: 'gradle'
       - name: Run tests
         run: xvfb-run --auto-servernum ./gradlew check -x checkstyleJmh -x checkstyleMain -x checkstyleTest -x modernizer
@@ -138,8 +138,8 @@ jobs:
       - name: Set up JDK
         uses: actions/setup-java@v3
         with:
-          java-version: 20
-          distribution: 'temurin'
+          java-version: 21.0.1
+          distribution: 'liberica'
           cache: 'gradle'
       - name: Run tests on PostgreSQL
         run: ./gradlew databaseTest --rerun-tasks
@@ -175,8 +175,8 @@ jobs:
       - name: Set up JDK
         uses: actions/setup-java@v3
         with:
-          java-version: 20
-          distribution: 'temurin'
+          java-version: 21.0.1
+          distribution: 'liberica'
           cache: 'gradle'
       - name: Run GUI tests
         run: xvfb-run --auto-servernum ./gradlew guiTest
@@ -216,8 +216,8 @@ jobs:
       - name: Set up JDK
         uses: actions/setup-java@v3
         with:
-          java-version: 20
-          distribution: 'temurin'
+          java-version: 21.0.1
+          distribution: 'liberica'
           cache: 'gradle'
       - name: Update test coverage metrics
         if: steps.checksecrets.outputs.secretspresent == 'YES'

build.gradle

@@ -5,7 +5,7 @@ import org.jabref.build.xjc.XjcTask
 plugins {
     id 'application'
 
-    id 'com.github.andygoossens.modernizer' version '1.8.0'
+    id 'com.github.andygoossens.modernizer' version '1.9.0'
 
     id 'me.champeau.jmh' version '0.7.1'
 
@@ -41,15 +41,15 @@ group = "org.jabref"
 version = project.findProperty('projVersion') ?: '100.0.0'
 
 java {
-    sourceCompatibility = JavaVersion.VERSION_19
-    targetCompatibility = JavaVersion.VERSION_19
+    sourceCompatibility = JavaVersion.VERSION_21
+    targetCompatibility = JavaVersion.VERSION_21
     // Workaround needed for Eclipse, probably because of https://github.com/gradle/gradle/issues/16922
     // Should be removed as soon as Gradle 7.0.1 is released ( https://github.com/gradle/gradle/issues/16922#issuecomment-828217060 )
     modularity.inferModulePath.set(false)
 
     toolchain {
         // If this is updated, also update .devcontainer/devcontainer.json#L34
-        languageVersion = JavaLanguageVersion.of(20)
+        languageVersion = JavaLanguageVersion.of(21)
     }
 }
 

docs/getting-into-the-code/guidelines-for-setting-up-a-local-workspace/intellij-12-build.md

@@ -6,24 +6,24 @@ nav_order: 12
 
 # Step 2: Setup the build system: JDK and Gradle
 
-## Ensure that JDK 20 is available to IntelliJ
+## Ensure that JDK 21 is available to IntelliJ
 
-Ensure you have a Java 20 SDK configured by navigating to **File > Project Structure... > Platform Settings > SDKs**.
+Ensure you have a Java 21 SDK configured by navigating to **File > Project Structure... > Platform Settings > SDKs**.
 
-{% figure caption:"JDKs 11, 14, and 15 shown in available SDKs. JDK 20 is missing." %}
+{% figure caption:"JDKs 11, 14, and 15 shown in available SDKs. JDK 21 is missing." %}
 ![Plattform Settings - SDKs](intellij-choose-jdk-adoptopenjdk-on-windows-project-settings.png)
 {% endfigure %}
 
-If there is another JDK than JDK 20 selected, click on the plus button and choose "Download JDK..."
+If there is another JDK than JDK 21 selected, click on the plus button and choose "Download JDK..."
 
 {% figure caption:"Download JDK..." %}
 ![Plattform Settings - SDKs - plus button - Download JDK...](guidelines-select-download-jdk.png)
 {% endfigure %}
 
-Select JDK version 20 and then Eclipse Temurin (showing JDK 18 as example).
+Select JDK version 21 and then Eclipse Temurin.
 
-{% figure caption:"Example for JDK 18 - Choose Eclipse Temurin" %}
-![Download Eclipse Temurin](guidelines-select-jdk-18-eclipse-temurin.png)
+{% figure caption:"Example for JDK 21 - Choose Eclipse Temurin" %}
+![Download Eclipse Temurin](guidelines-intellij-select-jdk-eclipse-temurin.png)
 {% endfigure %}
 
 After clicking "Download", IntelliJ installs Eclipse Temurin:
@@ -32,20 +32,26 @@ After clicking "Download", IntelliJ installs Eclipse Temurin:
 ![IntelliJ installs Eclipse Temurin](guidelines-intellij-installs-temurin.png)
 {% endfigure %}
 
-Navigate to **Project Settings > Project** and ensure that the projects' SDK is Java 20
+Open the module settings: Right click on "JabRef" and select "Open Module Settings":
 
-{% figure caption:"Project SDK is pinned to the downloaded SDK (showing JDK 18 as example)" %}
-![Project SDK is JDK 18](guidelines-intellij-project-settings-jdk18.png)
+{% figure caption:"Open IntelliJ Module Settings" %}
+![IntelliJ Module Settings](guidelines-intellij-open-module-settings.png)
+{% endfigure %}
+
+Navigate to **Project Settings > Project** and ensure that the projects' SDK is Java 21.
+
+{% figure caption:"Project SDK is pinned to the downloaded SDK (showing JDK 21 as example)" %}
+![Project SDK is JDK 21](guidelines-intellij-project-settings-jdk.png)
 {% endfigure %}
 
 Click "OK" to store the changes.
 
 ## Configure the Build System
 
-Navigate to **File > Settings... > Build, Execution, Deployment > Build Tools > Gradle** and select the "Project SDK" as the Gradle JVM at the bottom. If that does not exist, just select a JDK 20.
+Navigate to **File > Settings... > Build, Execution, Deployment > Build Tools > Gradle** and select the "Project SDK" as the Gradle JVM at the bottom. If that does not exist, just select a JDK 21.
 
-{% figure caption:"Gradle JVM is project SDK (showing JDK 18 as example)" %}
-![Gradle JVM is project SDK](guidelines-settings-gradle-gradlejvm-is-projectjvm.png)
+{% figure caption:"Gradle JVM is project SDK (showing JDK 21 as example)" %}
+![Gradle JVM is project SDK](guidelines-intellij-settings-gradle-gradlejvm-is-projectjvm.png)
 {% endfigure %}
 
 To prepare IntelliJ's build system additional steps are required:

src/main/java/org/jabref/logic/bst/BstFunctions.java

@@ -1,9 +1,9 @@
 package org.jabref.logic.bst;
 
+import java.util.Deque;
 import java.util.HashMap;
 import java.util.Map;
 import java.util.Optional;
-import java.util.Stack;
 import java.util.regex.Matcher;
 import java.util.regex.Pattern;
 
@@ -30,7 +30,7 @@ public class BstFunctions {
     private final Map<String, BstFunction> functions;
     private final String preamble;
 
-    private final Stack<Object> stack;
+    private final Deque<Object> stack;
     private final StringBuilder bbl;
 
     private int bstWarning = 0;
@@ -670,7 +670,7 @@ private void bstSkip(BstVMVisitor visitor, ParserRuleContext ctx) {
      * designers while debugging.
      */
     private void bstStack(BstVMVisitor visitor, ParserRuleContext ctx) {
-        while (!stack.empty()) {
+        while (!stack.isEmpty()) {
             LOGGER.debug("Stack entry {}", stack.pop());
         }
     }

src/main/java/org/jabref/logic/bst/BstVM.java

@@ -4,9 +4,9 @@
 import java.nio.file.Path;
 import java.util.ArrayList;
 import java.util.Collection;
+import java.util.Deque;
 import java.util.List;
 import java.util.Objects;
-import java.util.Stack;
 
 import org.jabref.model.database.BibDatabase;
 import org.jabref.model.entry.BibEntry;
@@ -93,7 +93,7 @@ public String render(Collection<BibEntry> bibEntries) {
         return render(bibEntries, null);
     }
 
-    protected Stack<Object> getStack() {
+    protected Deque<Object> getStack() {
         if (latestContext != null) {
             return latestContext.stack();
         } else {

src/main/java/org/jabref/logic/bst/BstVMContext.java

@@ -1,22 +1,24 @@
 package org.jabref.logic.bst;
 
 import java.nio.file.Path;
+import java.util.Deque;
 import java.util.HashMap;
+import java.util.LinkedList;
 import java.util.List;
 import java.util.Map;
 import java.util.Optional;
-import java.util.Stack;
 
 import org.jabref.model.database.BibDatabase;
 
 public record BstVMContext(List<BstEntry> entries,
                            Map<String, String> strings,
                            Map<String, Integer> integers,
                            Map<String, BstFunctions.BstFunction> functions,
-                           Stack<Object> stack,
+                           Deque<Object> stack,
                            BibDatabase bibDatabase,
                            Optional<Path> path) {
     public BstVMContext(List<BstEntry> entries, BibDatabase bibDatabase, Path path) {
-        this(entries, new HashMap<>(), new HashMap<>(), new HashMap<>(), new Stack<>(), bibDatabase, Optional.ofNullable(path));
+        // LinkedList instead of ArrayDeque, because we (currently) need null support
+        this(entries, new HashMap<>(), new HashMap<>(), new HashMap<>(), new LinkedList<>(), bibDatabase, Optional.ofNullable(path));
     }
 }