NOISSUE Fail launch if minimum Java requirement is not met

This will fail launch in the following conditions:
  1. A version greater than or equal to Minecraft 17w13a, and less than
     21w19a - and the Java version is less than 8.
  2. A version greater than or equal to Minecraft 21w19a - and the Java
     version is less than 16.

6 files changed, 66 insertions, 0 deletions

diff --git a/api/logic/CMakeLists.txt b/api/logic/CMakeLists.txt
index 17e22458..6d269714 100644
--- a/api/logic/CMakeLists.txt
+++ b/api/logic/CMakeLists.txt
@@ -246,6 +246,8 @@ set(MINECRAFT_SOURCES
     minecraft/launch/ReconstructAssets.h
     minecraft/launch/ScanModFolders.cpp
     minecraft/launch/ScanModFolders.h
+    minecraft/launch/VerifyJavaInstall.cpp
+    minecraft/launch/VerifyJavaInstall.h
 
     minecraft/legacy/LegacyModList.h
     minecraft/legacy/LegacyModList.cpp
diff --git a/api/logic/minecraft/MinecraftInstance.cpp b/api/logic/minecraft/MinecraftInstance.cpp
index fdf9bd61..ea1e47b6 100644
--- a/api/logic/minecraft/MinecraftInstance.cpp
+++ b/api/logic/minecraft/MinecraftInstance.cpp
@@ -23,6 +23,7 @@
 #include "minecraft/launch/ClaimAccount.h"
 #include "minecraft/launch/ReconstructAssets.h"
 #include "minecraft/launch/ScanModFolders.h"
+#include "minecraft/launch/VerifyJavaInstall.h"
 #include "java/launch/CheckJava.h"
 #include "java/JavaUtils.h"
 #include "meta/Index.h"
@@ -915,6 +916,11 @@ shared_qobject_ptr<LaunchTask> MinecraftInstance::createLaunchTask(AuthSessionPt
         process->appendStep(new ReconstructAssets(pptr));
     }
 
+    // verify that minimum Java requirements are met
+    {
+        process->appendStep(new VerifyJavaInstall(pptr));
+    }
+
     {
         // actually launch the game
         auto method = launchMethod();
diff --git a/api/logic/minecraft/VersionFilterData.cpp b/api/logic/minecraft/VersionFilterData.cpp
index a47fc0a0..38e7b60c 100644
--- a/api/logic/minecraft/VersionFilterData.cpp
+++ b/api/logic/minecraft/VersionFilterData.cpp
@@ -65,4 +65,7 @@ VersionFilterData::VersionFilterData()
         QSet<QString>{"net.java.jinput:jinput",     "net.java.jinput:jinput-platform",
                       "net.java.jutils:jutils",     "org.lwjgl.lwjgl:lwjgl",
                       "org.lwjgl.lwjgl:lwjgl_util", "org.lwjgl.lwjgl:lwjgl-platform"};
+
+    java8BeginsDate  = timeFromS3Time("2017-03-30T09:32:19+00:00");
+    java16BeginsDate = timeFromS3Time("2021-05-12T11:19:15+00:00");
 }
diff --git a/api/logic/minecraft/VersionFilterData.h b/api/logic/minecraft/VersionFilterData.h
index afd4502b..d100acc3 100644
--- a/api/logic/minecraft/VersionFilterData.h
+++ b/api/logic/minecraft/VersionFilterData.h
@@ -23,5 +23,9 @@ struct VersionFilterData
     QDateTime legacyCutoffDate;
     // Libraries that belong to LWJGL
     QSet<QString> lwjglWhitelist;
+    // release date of first version to require Java 8 (17w13a)
+    QDateTime java8BeginsDate;
+    // release data of first version to require Java 16 (21w19a)
+    QDateTime java16BeginsDate;
 };
 extern VersionFilterData MULTIMC_LOGIC_EXPORT g_VersionFilterData;
diff --git a/api/logic/minecraft/launch/VerifyJavaInstall.cpp b/api/logic/minecraft/launch/VerifyJavaInstall.cpp
new file mode 100644
index 00000000..657669af
--- /dev/null
+++ b/api/logic/minecraft/launch/VerifyJavaInstall.cpp
@@ -0,0 +1,34 @@
+#include "VerifyJavaInstall.h"
+
+#include <launch/LaunchTask.h>
+#include <minecraft/MinecraftInstance.h>
+#include <minecraft/PackProfile.h>
+#include <minecraft/VersionFilterData.h>
+
+void VerifyJavaInstall::executeTask() {
+    auto m_inst = std::dynamic_pointer_cast<MinecraftInstance>(m_parent->instance());
+
+    auto javaVersion = m_inst->getJavaVersion();
+    auto minecraftComponent = m_inst->getPackProfile()->getComponent("net.minecraft");
+
+    // Java 16 requirement
+    if (minecraftComponent->getReleaseDateTime() >= g_VersionFilterData.java16BeginsDate) {
+        if (javaVersion.major() < 16) {
+            emit logLine("Minecraft 21w19a and above require the use of Java 16",
+                         MessageLevel::Fatal);
+            emitFailed(tr("Minecraft 21w19a and above require the use of Java 16"));
+            return;
+        }
+    }
+    // Java 8 requirement
+    else if (minecraftComponent->getReleaseDateTime() >= g_VersionFilterData.java8BeginsDate) {
+        if (javaVersion.major() < 8) {
+            emit logLine("Minecraft 17w13a and above require the use of Java 8",
+                         MessageLevel::Fatal);
+            emitFailed(tr("Minecraft 17w13a and above require the use of Java 8"));
+            return;
+        }
+    }
+
+    emitSucceeded();
+}
diff --git a/api/logic/minecraft/launch/VerifyJavaInstall.h b/api/logic/minecraft/launch/VerifyJavaInstall.h
new file mode 100644
index 00000000..a553106d
--- /dev/null
+++ b/api/logic/minecraft/launch/VerifyJavaInstall.h
@@ -0,0 +1,17 @@
+#pragma once
+
+#include <launch/LaunchStep.h>
+
+class VerifyJavaInstall : public LaunchStep {
+    Q_OBJECT
+
+public:
+    explicit VerifyJavaInstall(LaunchTask *parent) : LaunchStep(parent) {
+    };
+    ~VerifyJavaInstall() override = default;
+
+    void executeTask() override;
+    bool canAbort() const override {
+        return false;
+    }
+};