Java Utililty Methods Reflection Primitive

void addPrimitiveToWrapperRelation(Class primitiveClass, Class wrapperClass)
add Primitive To Wrapper Relation

PRIMITIVE_TO_WRAPPERS_MAP.put(primitiveClass, wrapperClass);
WRAPPERS_TO_PRIMITIVE_MAP.put(wrapperClass, primitiveClass);

float calculateDistancePrimitive(Class a, Class b)
calculate Distance Primitive

if (b == Character.class || b == Boolean.class)
 return -1F;
if (a == Character.class)
 a = Short.class;
int indexA = PRIMITIVE_WIDENING.indexOf(a);
int indexB = PRIMITIVE_WIDENING.indexOf(b);
if (indexA < 0 || indexB < 0)
 return -1F;
...

boolean canCoerceLiteralNumberExpr(Class type)
can Coerce Literal Number Expr

final List<? extends Class<?>> classes = Arrays.asList(int.class, long.class, double.class);
return classes.contains(type);

T castToPrimitive(Object start, Class prim)
cast To Primitive

try {
 if (start == null) {
 return (T) defaultPrimitiveValues.get(prim);
 if (start instanceof Boolean) {
 start = ((Boolean) start) ? 1 : 0;
 if (start instanceof Character) {
...

Class convertPrimitiveToObjectClass(Class clazz)
The class equivalent of (manual) autoboxing.

if (isPrimitiveClass(clazz)) {
 return primitiveToObjectClassMap.get(clazz);
return clazz;

Class convertPrimitiveToWrapper(Class clazz)
Gets the equivalent class to convert to if the given clazz is a primitive.

if (clazz == null || !clazz.isPrimitive())
 return clazz;
return (Class) primativeToWrapperMap.get(clazz);

Class convertPrimitiveToWrapper(Class clazz)
Checks whether a given class object is a primitive and returns its wrapper class (except for void where always the primitive class is used).

Class<?> result = clazz;
if (clazz.isPrimitive()) {
 return primitiveWrapperClasses.get(clazz.getName());
return result;

Class convertToPrimitive(Class type)
convert To Primitive

if (type == null || type.isPrimitive()) {
 throw new IllegalArgumentException(
 "Given class type is wrong. Either it is null or is a primitive. given-class[" + type + "]");
return wrapperToprimitives.get(type);

Class convertWrapperToPrimitive(Class clazz)
convert Wrapper To Primitive

Class<?> result = clazz;
if (!clazz.isPrimitive()) {
 return wrapperPrimitiveClasses.get(clazz.getName());
return result;

K createDefaultPrimitive(Class type)
Returns the default value (JLS 4.12.5) of a primitive type.

return type.cast(PRIMITIVE_DEFAULTS.get(type));