Fix 1_16_R2 bukkit config reload error

- Refactored VersionParam to include patch version specification
- Added ConstructorParam to cache constructors & get the default constructor.

Common/src/main/java/net/frankheijden/serverutils/common/reflection/ConstructorParam.java

@@ -0,0 +1,14 @@
+package net.frankheijden.serverutils.common.reflection;
+
+public class ConstructorParam {
+
+    public final Class<?>[] params;
+
+    private ConstructorParam(Class<?>[] params) {
+        this.params = params;
+    }
+
+    public static ConstructorParam constructorOf(Class<?>... params) {
+        return new ConstructorParam(params);
+    }
+}

Common/src/main/java/net/frankheijden/serverutils/common/reflection/FieldParam.java

@@ -3,8 +3,9 @@ package net.frankheijden.serverutils.common.reflection;
 import static net.frankheijden.serverutils.common.reflection.VersionParam.ALL_VERSIONS;
 
 public class FieldParam {
-    public String field;
-    public VersionParam versionParam;
+
+    public final String field;
+    public final VersionParam versionParam;
 
     private FieldParam(String field, VersionParam versionParam) {
         this.field = field;

Common/src/main/java/net/frankheijden/serverutils/common/reflection/MethodParam.java

@@ -4,9 +4,9 @@ import static net.frankheijden.serverutils.common.reflection.VersionParam.ALL_VE
 
 public class MethodParam {
 
-    public String method;
-    public VersionParam versionParam;
-    public Class<?>[] params;
+    public final String method;
+    public final VersionParam versionParam;
+    public final Class<?>[] params;
 
     private MethodParam(String method, VersionParam versionParam, Class<?>... params) {
         this.method = method;

Common/src/main/java/net/frankheijden/serverutils/common/reflection/ReflectionUtils.java

@@ -1,9 +1,12 @@
 package net.frankheijden.serverutils.common.reflection;
 
+import java.lang.reflect.Constructor;
 import java.lang.reflect.Field;
 import java.lang.reflect.InvocationTargetException;
 import java.lang.reflect.Method;
+import java.util.ArrayList;
 import java.util.HashMap;
+import java.util.List;
 import java.util.Map;
 
 public abstract class ReflectionUtils {
@@ -122,6 +125,24 @@ public abstract class ReflectionUtils {
         return map;
     }
 
+    /**
+     * Fetches all constructors by their parameter input.
+     * @param clazz The class to find constructors on.
+     * @param constructorParams The constructor parameters.
+     * @return The list of constructors.
+     */
+    public static List<Constructor<?>> getAllConstructors(Class<?> clazz, ConstructorParam... constructorParams) {
+        List<Constructor<?>> constructors = new ArrayList<>();
+        for (ConstructorParam constructorParam : constructorParams) {
+            try {
+                constructors.add(clazz.getDeclaredConstructor(constructorParam.params));
+            } catch (NoSuchMethodException ignored) {
+                //
+            }
+        }
+        return constructors;
+    }
+
     /**
      * Invokes a method on an instance.
      * Will return null if method not present in map.

Common/src/main/java/net/frankheijden/serverutils/common/reflection/VersionParam.java

@@ -2,29 +2,73 @@ package net.frankheijden.serverutils.common.reflection;
 
 public class VersionParam {
 
-    public static VersionParam ALL_VERSIONS = new VersionParam(Integer.MIN_VALUE, Integer.MAX_VALUE);
+    public static final Version MIN_VERSION = new Version(Integer.MIN_VALUE, Integer.MIN_VALUE);
+    public static final Version MAX_VERSION = new Version(Integer.MAX_VALUE, Integer.MAX_VALUE);
+    public static final VersionParam ALL_VERSIONS = new VersionParam(MIN_VERSION, MAX_VERSION);
 
-    public int min;
-    public int max;
+    public final Version min;
+    public final Version max;
 
     private VersionParam(int min, int max) {
+        this(min, Integer.MIN_VALUE, max, Integer.MAX_VALUE);
+    }
+
+    private VersionParam(int min, int minPatch, int max, int maxPatch) {
+        this(new Version(min, minPatch), new Version(max, maxPatch));
+    }
+
+    private VersionParam(Version min, Version max) {
         this.min = min;
         this.max = max;
     }
 
-    public static VersionParam versionOf(int ver) {
+    public static VersionParam exact(int minor) {
+        return new VersionParam(minor, minor);
+    }
+
+    public static VersionParam exact(Version ver) {
         return new VersionParam(ver, ver);
     }
 
-    public static VersionParam between(int min, int max) {
+    public static VersionParam between(int minMinor, int maxMinor) {
+        return new VersionParam(minMinor, maxMinor);
+    }
+
+    public static VersionParam between(Version min, Version max) {
         return new VersionParam(min, max);
     }
 
-    public static VersionParam min(int min) {
-        return between(min, Integer.MAX_VALUE);
+    public static VersionParam min(int minMinor) {
+        return between(minMinor, Integer.MAX_VALUE);
     }
 
-    public static VersionParam max(int max) {
-        return between(Integer.MIN_VALUE, max);
+    public static VersionParam min(Version min) {
+        return between(min, MAX_VERSION);
+    }
+
+    public static VersionParam max(int maxMinor) {
+        return between(Integer.MIN_VALUE, maxMinor);
+    }
+
+    public static VersionParam max(Version max) {
+        return between(MIN_VERSION, max);
+    }
+
+    public static class Version {
+        public final int minor;
+        public final int patch;
+
+        public Version(int minor, int patch) {
+            this.minor = minor;
+            this.patch = patch;
+        }
+
+        public int getMinor() {
+            return minor;
+        }
+
+        public int getPatch() {
+            return patch;
+        }
     }
 }