Made build in extension registration more resistant:

- Attempt to reduce the amount of exceptions that might slip through
  and fail to start Plan

Affects issues:
- Close #1134

Plan/api/src/main/java/com/djrapitops/plan/extension/extractor/ExtensionExtractor.java

@@ -68,8 +68,13 @@ public final class ExtensionExtractor {
         }
     }
 
-    private <T extends Annotation> Optional<T> getClassAnnotation(Class<T> ofClass) {
+    private static <V extends DataExtension, T extends Annotation> Optional<T> getClassAnnotation(Class<V> from, Class<T> ofClass) {
-        return Optional.ofNullable(extension.getClass().getAnnotation(ofClass));
+        return Optional.ofNullable(from.getAnnotation(ofClass));
+    }
+
+    public static <T extends DataExtension> String getPluginName(Class<T> extensionClass) {
+        return getClassAnnotation(extensionClass, PluginInfo.class).map(PluginInfo::name)
+                .orElseThrow(() -> new IllegalArgumentException("Given class had no PluginInfo annotation"));
     }
 
     private Method[] getMethods() {
@@ -282,8 +287,13 @@ public final class ExtensionExtractor {
         }
     }
 
+    private <T extends Annotation> Optional<T> getClassAnnotation(Class<T> ofClass) {
+        return getClassAnnotation(extension.getClass(), ofClass);
+    }
+
     private void extractPluginInfo() {
-        pluginInfo = getClassAnnotation(PluginInfo.class).orElseThrow(() -> new IllegalArgumentException("Given class had no PluginInfo annotation"));
+        pluginInfo = getClassAnnotation(PluginInfo.class)
+                .orElseThrow(() -> new IllegalArgumentException("Given class had no PluginInfo annotation"));
 
         if (pluginInfo.name().length() > 50) {
             warnings.add(extensionName + " PluginInfo 'name' was over 50 characters.");

Plan/common/src/main/java/com/djrapitops/plan/data/plugin/PluginsConfigSection.java

@@ -20,6 +20,8 @@ import com.djrapitops.plan.system.settings.config.ConfigNode;
 import com.djrapitops.plan.system.settings.config.PlanConfig;
 
 import java.io.IOException;
+import java.util.HashSet;
+import java.util.Set;
 
 /**
  * Class responsible for generating and generating settings for PluginData
@@ -74,4 +76,16 @@ public class PluginsConfigSection {
         ConfigNode section = getPluginsSection();
         return section.getBoolean(pluginName + ".Enabled");
     }
+
+    public Set<String> getDisabled() {
+        ConfigNode section = getPluginsSection();
+
+        Set<String> disabledPlugins = new HashSet<>();
+        for (ConfigNode plugin : section.getChildren()) {
+            if (!plugin.getBoolean("Enabled")) {
+                disabledPlugins.add(plugin.getKey(false));
+            }
+        }
+        return disabledPlugins;
+    }
 }

Plan/common/src/main/java/com/djrapitops/plan/extension/ExtensionServiceImplementation.java

@@ -83,11 +83,11 @@ public class ExtensionServiceImplementation implements ExtensionService {
 
     public void register() {
         try {
-            extensionRegister.registerBuiltInExtensions();
+            extensionRegister.registerBuiltInExtensions(config.getPluginsConfigSection().getDisabled());
             if (Check.isBukkitAvailable()) extensionRegister.registerBukkitExtensions();
             if (Check.isBungeeAvailable()) extensionRegister.registerBungeeExtensions();
         } catch (IllegalStateException failedToRegisterOne) {
-            logger.warn("One or more extensions failed to register:");
+            logger.warn("One or more extensions failed to register, see suppressed exceptions.");
             errorHandler.log(L.WARN, this.getClass(), failedToRegisterOne);
         }
     }

Plan/common/src/main/java/com/djrapitops/plan/system/settings/config/ConfigNode.java

@@ -349,6 +349,10 @@ public class ConfigNode {
         return nodeOrder;
     }
 
+    public Collection<ConfigNode> getChildren() {
+        return childNodes.values();
+    }
+
     @Override
     public boolean equals(Object o) {
         if (this == o) return true;

Plan/extensions/src/main/java/com/djrapitops/plan/extension/implementation/ExtensionRegister.java

@@ -19,10 +19,12 @@ package com.djrapitops.plan.extension.implementation;
 import com.djrapitops.extension.*;
 import com.djrapitops.plan.extension.DataExtension;
 import com.djrapitops.plan.extension.ExtensionService;
+import com.djrapitops.plan.extension.extractor.ExtensionExtractor;
 
 import javax.inject.Inject;
 import javax.inject.Singleton;
 import java.util.Optional;
+import java.util.Set;
 import java.util.function.Supplier;
 
 /**
@@ -34,47 +36,49 @@ import java.util.function.Supplier;
 public class ExtensionRegister {
 
     private IllegalStateException registerException;
+    private Set<String> disabledExtensions;
 
     @Inject
     public ExtensionRegister() {
         /* Required for dagger injection */
     }
 
-    public void registerBuiltInExtensions() {
+    public void registerBuiltInExtensions(Set<String> disabledExtensions) {
+        this.disabledExtensions = disabledExtensions;
         // No need to catch exceptions here,
         // registerBuiltInExtensions method will not be called unless Plan has enabled properly
         ExtensionService extensionService = ExtensionService.getInstance();
 
-        register(new AACExtensionFactory()::createExtension);
+        register(new AACExtensionFactory()::createExtension, AACExtensionFactory.class);
-        register(new AdvancedAchievementsExtensionFactory()::createExtension);
+        register(new AdvancedAchievementsExtensionFactory()::createExtension, AdvancedAchievementsExtensionFactory.class);
-        register(new AdvancedBanExtensionFactory()::createExtension);
+        register(new AdvancedBanExtensionFactory()::createExtension, AdvancedBanExtensionFactory.class);
-        register(new ASkyBlockExtensionFactory()::createExtension);
+        register(new ASkyBlockExtensionFactory()::createExtension, ASkyBlockExtensionFactory.class);
-        register(new BanManagerExtensionFactory()::createExtension);
+        register(new BanManagerExtensionFactory()::createExtension, BanManagerExtensionFactory.class);
-        register(new CoreProtectExtensionFactory()::createExtension);
+        register(new CoreProtectExtensionFactory()::createExtension, CoreProtectExtensionFactory.class);
-        register(new DiscordSRVExtensionFactory()::createExtension);
+        register(new DiscordSRVExtensionFactory()::createExtension, DiscordSRVExtensionFactory.class);
         registerEssentialsExtension(extensionService);
-        register(new GriefPreventionExtensionFactory()::createExtension);
+        register(new GriefPreventionExtensionFactory()::createExtension, GriefPreventionExtensionFactory.class);
-        register(new GriefPreventionSpongeExtensionFactory()::createExtension);
+        register(new GriefPreventionSpongeExtensionFactory()::createExtension, GriefPreventionSpongeExtensionFactory.class);
-        register(new GriefPreventionPlusExtensionFactory()::createExtension);
+        register(new GriefPreventionPlusExtensionFactory()::createExtension, GriefPreventionPlusExtensionFactory.class);
-        register(new McMMOExtensionFactory()::createExtension);
+        register(new McMMOExtensionFactory()::createExtension, McMMOExtensionFactory.class);
         registerMinigameLibExtensions(extensionService);
-        register(new NucleusExtensionFactory()::createExtension);
+        register(new NucleusExtensionFactory()::createExtension, NucleusExtensionFactory.class);
-        register(new NuVotifierExtensionFactory()::createExtension);
+        register(new NuVotifierExtensionFactory()::createExtension, NuVotifierExtensionFactory.class);
-        register(new ProtocolSupportExtensionFactory()::createExtension);
+        register(new ProtocolSupportExtensionFactory()::createExtension, ProtocolSupportExtensionFactory.class);
-        register(new RedProtectExtensionFactory()::createExtension);
+        register(new RedProtectExtensionFactory()::createExtension, RedProtectExtensionFactory.class);
-        register(new SpongeEconomyExtensionFactory()::createExtension);
+        register(new SpongeEconomyExtensionFactory()::createExtension, SpongeEconomyExtensionFactory.class);
-        register(new SuperbVoteExtensionFactory()::createExtension);
+        register(new SuperbVoteExtensionFactory()::createExtension, SuperbVoteExtensionFactory.class);
-        register(new VaultExtensionFactory()::createExtension);
+        register(new VaultExtensionFactory()::createExtension, VaultExtensionFactory.class);
 
         if (registerException != null) throw registerException;
     }
 
     public void registerBukkitExtensions() {
-        register(new ViaVersionBukkitExtensionFactory()::createExtension);
+        register(new ViaVersionBukkitExtensionFactory()::createExtension, ViaVersionBukkitExtensionFactory.class);
     }
 
     public void registerBungeeExtensions() {
-        register(new ViaVersionBungeeExtensionFactory()::createExtension);
+        register(new ViaVersionBungeeExtensionFactory()::createExtension, ViaVersionBungeeExtensionFactory.class);
     }
 
     private void registerEssentialsExtension(ExtensionService extensionService) {
@@ -90,16 +94,26 @@ public class ExtensionRegister {
         }
     }
 
-    private void register(Supplier<Optional<DataExtension>> extension) {
+    private void register(Supplier<Optional<DataExtension>> extension, Class factory) {
         ExtensionService extensionService = ExtensionService.getInstance();
         try {
-            extension.get().ifPresent(extensionService::register);
+            Optional<DataExtension> optional = extension.get();
-        } catch (IllegalStateException e) {
+            if (!optional.isPresent()) return;
+            DataExtension dataExtension = optional.get();
+
+            String extensionName = ExtensionExtractor.getPluginName(dataExtension.getClass());
+            if (disabledExtensions.contains(extensionName)) return;
+
+            extensionService.register(dataExtension);
+        } catch (IllegalStateException | NoClassDefFoundError | IncompatibleClassChangeError e) {
+            // Places all exceptions to one exception with plugin information so that they can be reported.
             if (registerException == null) {
-                registerException = e;
+                registerException = new IllegalStateException("One or more extensions failed to register:");
-            } else {
+                registerException.setStackTrace(new StackTraceElement[0]);
-                registerException.addSuppressed(e);
             }
+            IllegalStateException info = new IllegalStateException(factory.getSimpleName() + " ran into exception when creating Extension", e);
+            info.setStackTrace(new StackTraceElement[0]);
+            registerException.addSuppressed(info);
         }
     }
 }