update the Gradle build tool to v9.0.0, JDK 17+ required to build

Author: stephengold

.github/workflows/push.yml

@@ -5,25 +5,14 @@ name: CI at GitHub
 on: [push]
 
 jobs:
-  Java8-Linux:
-    if: contains(toJson(github.event.commits), '[ci skip] ') == false
-    runs-on: ubuntu-22.04
-    steps:
-      - uses: actions/setup-java@v4
-        with:
-          distribution: 'zulu'
-          java-version: 8
-      - uses: actions/checkout@v5
-      - run: ./gradlew build javadoc --console=plain --stacktrace
-
-  Java11-Linux:
+  Java17-Linux:
     if: contains(toJson(github.event.commits), '[ci skip] ') == false
     runs-on: ubuntu-24.04
     steps:
       - uses: actions/setup-java@v4
         with:
           distribution: 'zulu'
-          java-version: 11
+          java-version: 17
       - uses: actions/checkout@v5
       - uses: gradle/actions/wrapper-validation@v4
       - run: ./gradlew build javadoc --console=plain --stacktrace

README.md

@@ -27,6 +27,7 @@ DacWizard was designed for a desktop environment with:
 ## How to build and run DacWizard from source
 
 1. Install a 64-bit [Java Development Kit (JDK)][adoptium],
+   version 17 or higher,
    if you don't already have one.
 2. Point the `JAVA_HOME` environment variable to your JDK installation:
    (In other words, set it to the path of a directory/folder

build.gradle.kts

@@ -9,7 +9,6 @@ plugins {
 
 val isMacOS = DefaultNativePlatform.getCurrentOperatingSystem().isMacOsX()
 val javaVersion = JavaVersion.current()
-val enableNativeAccess = javaVersion.isCompatibleWith(JavaVersion.VERSION_17)
 
 java {
     sourceCompatibility = JavaVersion.VERSION_1_8
@@ -43,16 +42,14 @@ checkstyle {
 
 tasks.withType<JavaCompile>().all { // Java compile-time options:
     options.compilerArgs.add("-Xdiags:verbose")
-    if (javaVersion.isCompatibleWith(JavaVersion.VERSION_20)) {
-        // Suppress warnings that source value 8 is obsolete.
-        options.compilerArgs.add("-Xlint:-options")
-    }
+
+    // Suppress warnings that source value 8 is obsolete:
+    options.compilerArgs.add("-Xlint:-options")
+
     options.compilerArgs.add("-Xlint:unchecked")
     //options.setDeprecation(true) // to provide detailed deprecation warnings
     options.encoding = "UTF-8"
-    if (javaVersion.isCompatibleWith(JavaVersion.VERSION_1_10)) {
-        options.release = 8
-    }
+    options.release = 8
 }
 
 tasks.withType<JavaExec>().all { // Java runtime options:
@@ -63,9 +60,7 @@ tasks.withType<JavaExec>().all { // Java runtime options:
     //args("--verbose") // to enable additional log output
     classpath = sourceSets.main.get().getRuntimeClasspath()
     enableAssertions = true
-    if (enableNativeAccess) {
-        jvmArgs("--enable-native-access=ALL-UNNAMED") // suppress System::load() warning
-    }
+    jvmArgs("--enable-native-access=ALL-UNNAMED") // suppress System::load() warning
     //jvmArgs("-verbose:gc")
     jvmArgs("-Xms1024m", "-Xmx1024m") // to enlarge the Java heap
     //jvmArgs("-XX:+UseG1GC", "-XX:MaxGCPauseMillis=10")

gradle/wrapper/gradle-wrapper.jar

@@ -1,6 +1,6 @@
 distributionBase=GRADLE_USER_HOME
 distributionPath=wrapper/dists
-distributionUrl=https\://services.gradle.org/distributions/gradle-8.14.3-bin.zip
+distributionUrl=https\://services.gradle.org/distributions/gradle-9.0.0-bin.zip
 networkTimeout=10000
 validateDistributionUrl=true
 zipStoreBase=GRADLE_USER_HOME