Java Utililty Methods Reflection Generic Type

List of utility methods to do Reflection Generic Type

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Description

The list of methods to do Reflection Generic Type are organized into topic(s).

Method

ClassgetGenericType(Object target)
get Generic Type 
return getGenericType(target, 0);
ClassgetGenericType(Type genType, int index)
get Generic Type 
if (!(genType instanceof ParameterizedType)) {
    while (!Object.class.equals(genType) && !(genType instanceof ParameterizedType)) {
        genType = ((Class) genType).getGenericSuperclass();
    if (Object.class.equals(genType)) {
        return Object.class;
Type[] params = ((ParameterizedType) genType).getActualTypeArguments();
if (index >= params.length || index < 0) {
    return Object.class;
if (!(params[index] instanceof Class)) {
    return Object.class;
return (Class) params[index];
ClassgetGenericType(Type t, int index)
get Generic Type 
if (t == null) {
    return null;
if (!(t instanceof ParameterizedType)) {
    return null;
ParameterizedType ptype = (ParameterizedType) t;
if ((ptype.getActualTypeArguments() == null) || (ptype.getActualTypeArguments().length < (index + 1))) {
...
ClassgetGenericType(Type type)
get Generic Type 
return getGenericType(type, 0);
Type[]getGenericTypeArguments(Method m, int i)
get Generic Type Arguments 
try {
    Type t = m.getGenericParameterTypes()[i];
    if (t instanceof ParameterizedType) {
        ParameterizedType pt = (ParameterizedType) t;
        return pt.getActualTypeArguments();
} catch (Exception e) {
    System.out.println("Error probing generic type arguments!");
...
StringgetGenericTypeName(Method method)
Get generic type of specific method's return type in string. 
String genericTypeName = null;
String returnTypeName = method.getGenericReturnType().toString();
if (returnTypeName.matches(".*<.*>")) {
    genericTypeName = returnTypeName.substring(returnTypeName.indexOf("<") + 1,
            returnTypeName.indexOf(">"));
return genericTypeName;
Type[]getGenericTypes(Constructor targetConstructor, Integer constructorArgOrderingNumber)
Gets the generic types for a given constructor argument (specified by its ordering number). 
Type[] genericParameterTypes = targetConstructor.getGenericParameterTypes();
ParameterizedType type = (ParameterizedType) genericParameterTypes[constructorArgOrderingNumber - 1];
return type.getActualTypeArguments();
Type[]getGenericTypes(final Type type)
get Generic Types 
if (type instanceof ParameterizedType) {
    if (type != null) {
        return ((ParameterizedType) type).getActualTypeArguments();
return new Class[] { Object.class };