chore: restructure 'platform' package and add 'jre' package

src/main/java/org/terasology/launcher/LauncherInitTask.java

@@ -24,7 +24,7 @@
 import org.terasology.launcher.util.LauncherDirectoryUtils;
 import org.terasology.launcher.util.LauncherManagedDirectory;
 import org.terasology.launcher.util.LauncherStartFailedException;
-import org.terasology.launcher.util.Platform;
+import org.terasology.launcher.platform.Platform;
 
 import java.io.IOException;
 import java.net.URI;

src/main/java/org/terasology/launcher/game/GameStarter.java

@@ -8,7 +8,7 @@
 import org.slf4j.LoggerFactory;
 import org.slf4j.event.Level;
 import org.terasology.launcher.util.JavaHeapSize;
-import org.terasology.launcher.util.Platform;
+import org.terasology.launcher.platform.Platform;
 
 import java.io.IOException;
 import java.nio.file.Path;

src/main/java/org/terasology/launcher/jre/JREArtefact.java

@@ -0,0 +1,22 @@
+// Copyright 2023 The Terasology Foundation
+// SPDX-License-Identifier: Apache-2.0
+
+package org.terasology.launcher.jre;
+
+import org.terasology.launcher.platform.Platform;
+
+//TODO(Java17): make this a 'record'
+public final class JREArtefact {
+
+    public final String url;
+    public final String checksum;
+    public final Platform platform;
+    public final int version;
+
+    public JREArtefact(int version, Platform platform,String url, String checksum) {
+        this.url = url;
+        this.checksum = checksum;
+        this.platform = platform;
+        this.version = version;
+    }
+}

src/main/java/org/terasology/launcher/jre/ManagedJRE.java

@@ -0,0 +1,88 @@
+// Copyright 2023 The Terasology Foundation
+// SPDX-License-Identifier: Apache-2.0
+
+package org.terasology.launcher.jre;
+
+import com.google.common.collect.Lists;
+import com.google.common.collect.Sets;
+import org.terasology.launcher.platform.Arch;
+import org.terasology.launcher.platform.OS;
+import org.terasology.launcher.platform.Platform;
+
+import java.util.HashSet;
+import java.util.Set;
+
+public final class ManagedJRE {
+
+    public static final Set<Integer> SUPPORTED_JAVA_VERSIONS = Sets.newHashSet(8, 11, 17);
+
+    private static final Set<JREArtefact> supportedJavaVersions;
+
+    static {
+        supportedJavaVersions = new HashSet<>();
+
+
+        supportedJavaVersions.addAll(
+                Lists.newArrayList(
+                        // Linux
+                        new JREArtefact(8,
+                                new Platform(OS.LINUX, Arch.X64),
+                                "https://github.com/adoptium/temurin8-binaries/releases/download/jdk8u392-b08/OpenJDK8U-jre_x64_linux_hotspot_8u392b08.tar.gz",
+                                "91d31027da0d985be3549714389593d9e0da3da5057d87e3831c7c538b9a2a0f"
+                        ),
+                        new JREArtefact(11,
+                                new Platform(OS.LINUX, Arch.X64),
+                                "https://github.com/adoptium/temurin11-binaries/releases/download/jdk-11.0.21%2B9/OpenJDK11U-jre_x64_linux_hotspot_11.0.21_9.tar.gz",
+                                "156861bb901ef18759e05f6f008595220c7d1318a46758531b957b0c950ef2c3"
+                        ),
+                        new JREArtefact(17,
+                                new Platform(OS.LINUX, Arch.X64),
+                                "https://github.com/adoptium/temurin17-binaries/releases/download/jdk-17.0.9%2B9.1/OpenJDK17U-jre_x64_linux_hotspot_17.0.9_9.tar.gz",
+                                "c37f729200b572884b8f8e157852c739be728d61d9a1da0f920104876d324733"
+                        ),
+                        // Mac
+                        new JREArtefact(8,
+                                new Platform(OS.MAC, Arch.X64),
+                                "https://github.com/adoptium/temurin8-binaries/releases/download/jdk8u392-b08/OpenJDK8U-jre_x64_mac_hotspot_8u392b08.tar.gz",
+                                "f1f15920ed299e10c789aef6274d88d45eb21b72f9a7b0d246a352107e344e6a"
+                        ),
+                        new JREArtefact(11,
+                                new Platform(OS.MAC, Arch.X64),
+                                "https://github.com/adoptium/temurin11-binaries/releases/download/jdk-11.0.21%2B9/OpenJDK11U-jre_x64_mac_hotspot_11.0.21_9.tar.gz",
+                                "43d29affe994a09de31bf2fb6f8ab6d6792ba4267b9a2feacaa1f6e042481b9b"
+                        ),
+                        new JREArtefact(17,
+                                new Platform(OS.MAC, Arch.X64),
+                                "https://github.com/adoptium/temurin17-binaries/releases/download/jdk-17.0.9%2B9.1/OpenJDK17U-jre_x64_mac_hotspot_17.0.9_9.tar.gz",
+                                "c69b37ea72136df49ce54972408803584b49b2c91b0fbc876d7125e963c7db37"
+                        ),
+                        // Window
+                        new JREArtefact(8,
+                                new Platform(OS.WINDOWS, Arch.X64),
+                                "https://github.com/adoptium/temurin8-binaries/releases/download/jdk8u392-b08/OpenJDK8U-jre_x64_mac_hotspot_8u392b08.tar.gz",
+                                "a6b7e671cc12f9fc16db59419bda8be00da037e14aaf5d5afb78042c145b76ed"
+                        ),
+                        new JREArtefact(11,
+                                new Platform(OS.WINDOWS, Arch.X64),
+                                "https://github.com/adoptium/temurin11-binaries/releases/download/jdk-11.0.21%2B9/OpenJDK11U-jre_x64_windows_hotspot_11.0.21_9.zip",
+                                "a93d8334a85f6cbb228694346aad0353a8cb9ff3c84b5dc3221daf2c54a11e54"
+                        ),
+                        new JREArtefact(17,
+                                new Platform(OS.WINDOWS, Arch.X64),
+                                "https://github.com/adoptium/temurin17-binaries/releases/download/jdk-17.0.9%2B9.1/OpenJDK17U-jre_x64_windows_hotspot_17.0.9_9.zip",
+                                "6c491d6f8c28c6f451f08110a30348696a04b009f8c58592191046e0fab1477b"
+                        )
+                ));
+
+        for (var v : supportedJavaVersions) {
+            System.out.println(v.url);
+        }
+    }
+
+    public static JREArtefact getJreFor(Platform platform, int version) throws UnsupportedJREException {
+        return supportedJavaVersions.stream()
+                .filter(jre -> jre.platform.equals(platform) && jre.version == version)
+                .findFirst()
+                .orElseThrow(() -> new UnsupportedJREException(platform, version));
+    }
+}

src/main/java/org/terasology/launcher/jre/UnsupportedJREException.java

@@ -0,0 +1,21 @@
+// Copyright 2023 The Terasology Foundation
+// SPDX-License-Identifier: Apache-2.0
+
+package org.terasology.launcher.jre;
+
+import org.terasology.launcher.platform.Platform;
+
+public class UnsupportedJREException extends Exception {
+    private Platform platform;
+    private int version;
+
+    public UnsupportedJREException(Platform platform, int version) {
+        this.platform = platform;
+        this.version = version;
+    }
+
+    @Override
+    public String getMessage() {
+        return "UnsupportedJre: No managed JRE supported for Java version " + version + " and platform " + platform;
+    }
+}

src/main/java/org/terasology/launcher/platform/Arch.java

@@ -0,0 +1,9 @@
+// Copyright 2023 The Terasology Foundation
+// SPDX-License-Identifier: Apache-2.0
+
+package org.terasology.launcher.platform;
+
+public enum Arch {
+    X64,
+    X86;
+}

src/main/java/org/terasology/launcher/platform/OS.java

@@ -0,0 +1,10 @@
+// Copyright 2023 The Terasology Foundation
+// SPDX-License-Identifier: Apache-2.0
+
+package org.terasology.launcher.platform;
+
+public enum OS {
+    WINDOWS,
+    MAC,
+    LINUX;
+}

src/main/java/org/terasology/launcher/util/Platform.java → src/main/java/org/terasology/launcher/platform/Platform.java

@@ -1,70 +1,87 @@
-// Copyright 2020 The Terasology Foundation
+// Copyright 2023 The Terasology Foundation
 // SPDX-License-Identifier: Apache-2.0
 
-package org.terasology.launcher.util;
+package org.terasology.launcher.platform;
+
+import com.google.common.collect.Lists;
+import com.google.common.collect.Sets;
+
+import java.util.List;
+import java.util.Set;
 
 /**
  * A simplified representation of a computer platform as `os` and `arch`
  */
 public final class Platform {
+    public static final Set<Platform> SUPPORTED_PLATFORMS = Sets.newHashSet(
+            new Platform(OS.WINDOWS, Arch.X64),
+            new Platform(OS.LINUX, Arch.X64),
+            new Platform(OS.MAC, Arch.X64)
+    );
 
     private static final Platform PLATFORM = new Platform();
 
-    private String os;
-    private String arch;
+    private final OS os;
+    private final Arch arch;
 
     /**
      * Constructs platform information for the current host system.
      * Simplifies operating system name to one of `linux`, `mac`, `windows` if applicable.
      * Simplifies operating system architecture to one of `32` and `64` if applicable.
      */
-    private Platform() {
+    private Platform() throws UnsupportedPlatformException{
         final String platformOs = System.getProperty("os.name").toLowerCase();
         // TODO: consider using regex
         if (platformOs.startsWith("linux")) {
-            os = "linux";
+            os = OS.LINUX;
         } else if (platformOs.startsWith("mac os")) {
-            os = "mac";
+            os = OS.MAC;
         } else if (platformOs.startsWith("windows")) {
-            os = "windows";
+            os = OS.WINDOWS;
         } else {
-            os = platformOs;
+            throw new UnsupportedPlatformException();
         }
 
         final String platformArch = System.getProperty("os.arch");
         if (platformArch.equals("x86_64") || platformArch.equals("amd64")) {
-            arch = "64";
+            arch = Arch.X64;
         } else if (platformArch.equals("x86") || platformArch.equals("i386")) {
-            arch = "32";
+            arch = Arch.X86;
         } else {
-            arch = platformArch;
+            arch = Arch.X64;
+            //TODO: throw new UnsupportedPlatformException();
         }
     }
 
+    public Platform(OS os, Arch arch) {
+        this.os = os;
+        this.arch = arch;
+    }
+
     /**
      * @return the simplified operating system name as platform os
      */
     public String getOs() {
-        return os;
+        return os.name().toLowerCase();
     }
 
     /**
      * @return the simplified operating system architecture as platform arch
      */
     public String getArch() {
-        return arch;
+        return arch.name().toLowerCase();
     }
 
     public boolean isLinux() {
-        return os.equals("linux");
+        return os.equals(OS.LINUX);
     }
 
     public boolean isMac() {
-        return os.equals("mac");
+        return os.equals(OS.MAC);
     }
 
     public boolean isWindows() {
-        return os.equals("windows");
+        return os.equals(OS.WINDOWS);
     }
 
     public String toString() {
@@ -79,4 +96,22 @@ public String toString() {
     public static Platform getPlatform() {
         return PLATFORM;
     }
+
+    @Override
+    public boolean equals(Object o) {
+        if (this == o) return true;
+        if (o == null || getClass() != o.getClass()) return false;
+
+        Platform platform = (Platform) o;
+
+        if (os != platform.os) return false;
+        return arch == platform.arch;
+    }
+
+    @Override
+    public int hashCode() {
+        int result = os != null ? os.hashCode() : 0;
+        result = 31 * result + (arch != null ? arch.hashCode() : 0);
+        return result;
+    }
 }

src/main/java/org/terasology/launcher/platform/UnsupportedPlatformException.java

@@ -0,0 +1,7 @@
+// Copyright 2023 The Terasology Foundation
+// SPDX-License-Identifier: Apache-2.0
+
+package org.terasology.launcher.platform;
+
+public class UnsupportedPlatformException extends RuntimeException {
+}

src/main/java/org/terasology/launcher/util/LauncherDirectoryUtils.java

@@ -5,6 +5,7 @@
 
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
+import org.terasology.launcher.platform.Platform;
 
 import java.io.IOException;
 import java.net.URISyntaxException;

src/test/java/org/terasology/launcher/jre/ManagedJRETest.java

@@ -0,0 +1,26 @@
+// Copyright 2023 The Terasology Foundation
+// SPDX-License-Identifier: Apache-2.0
+
+package org.terasology.launcher.jre;
+
+import org.junit.jupiter.params.ParameterizedTest;
+import org.junit.jupiter.params.provider.Arguments;
+import org.junit.jupiter.params.provider.MethodSource;
+import org.terasology.launcher.platform.Platform;
+
+import java.util.stream.Stream;
+
+import static org.junit.jupiter.api.Assertions.assertDoesNotThrow;
+
+class ManagedJRETest {
+
+    @ParameterizedTest(name = "JRE in version {1} available for platform {0}")
+    @MethodSource("provideSupportedPlatforms")
+    void testJresForAllSupportedPlatforms(Platform platform, Integer javaVersion) {
+        assertDoesNotThrow(() -> ManagedJRE.getJreFor(platform, javaVersion));
+    }
+
+    private static Stream<Arguments> provideSupportedPlatforms() {
+        return Platform.SUPPORTED_PLATFORMS.stream().flatMap(p -> ManagedJRE.SUPPORTED_JAVA_VERSIONS.stream().map(v -> Arguments.of(p, v)));
+    }
+}