Java Utililty Methods Reflection Constructor Get

List of utility methods to do Reflection Constructor Get

Description

The list of methods to do Reflection Constructor Get are organized into topic(s).

Method

ConstructorgetConstructorOrFail(Class clazz, Class... argTypes)
Finds and returns the matching constructor in class clazz , or fails with a RuntimeException if the constructor cannot be found.
try {
    return clazz.getConstructor(argTypes);
} catch (Exception e) {
    throw new RuntimeException("Failed to get constructor '" + clazz.getSimpleName() + "' with args "
            + Arrays.asList(argTypes), e);
StringgetConstructors(Class cl)
Prints all constructors of a class
String clName = cl.getName();
Class superClass = cl.getSuperclass();
String superClassName = "";
if (superClass != null)
    superClassName = superClass.getName();
StringBuilder constr = new StringBuilder(
        "\n\nConstructors for class: " + clName + "  inherits  " + superClassName + " \n");
Constructor[] constructors = cl.getDeclaredConstructors();
...
String[]getConstructors(Class infoClass)
Gets constructors for a class.
String[] result = null;
Constructor[] constructors = null;
try {
    constructors = infoClass.getDeclaredConstructors();
} catch (SecurityException e) {
    return result;
if ((constructors == null) || (constructors.length == 0))
...
List>getConstructors(Class clazz)
get Constructors
List<Constructor<?>> lst = new ArrayList<Constructor<?>>();
Constructor<?>[] cotrs = clazz.getDeclaredConstructors();
for (Constructor<?> c : cotrs) {
    int im = c.getModifiers();
    if (!Modifier.isPublic(im))
        continue;
    lst.add(c);
return lst;
Constructor[]getConstructors(Class clazz, int args)
get Constructors
try {
    List<Constructor<?>> list = new ArrayList<Constructor<?>>();
    for (Constructor<?> constructor : clazz.getDeclaredConstructors()) {
        if (constructor.getParameterTypes().length == args) {
            constructor.setAccessible(true);
            list.add(constructor);
    for (Constructor<?> constructor : clazz.getDeclaredConstructors())
        if (constructor.getParameterTypes().length == args)
            list.add(constructor);
    return list.toArray(new Constructor<?>[list.size()]);
} catch (Throwable error) {
    return null;
Set>getConstructors(Class clazz)
get Constructors
return createConstructorList(clazz.getConstructors());
List>getConstructors(Class clazz, int modifier)
get Constructors
Constructor<?>[] constructors = clazz.getDeclaredConstructors();
List<Constructor<T>> ret = new ArrayList<Constructor<T>>(constructors.length);
for (Constructor<?> constructor : constructors) {
    if ((modifier & constructor.getModifiers()) != 0) {
        @SuppressWarnings("unchecked")
        Constructor<T> c = (Constructor<T>) constructor;
        ret.add(c);
return ret;
ListgetConstructors(final Class cl, final int params)
Gets all the constructors in the given class or super classes, even the redefined constructors are returned.
final List result = new LinkedList();
final Constructor[] ms = cl.getDeclaredConstructors();
for (int i = 0; i < ms.length; i++) {
    if (ms[i].getParameterTypes().length == params) {
        result.add(ms[i]);
return result;
...
StringgetConstructorSignature(final Constructor constructor)
Returns JVM type signature for a constructor.
return getMethodSignature(constructor.getParameterTypes(), Void.TYPE);
StringgetConstructorSignatureWithLongTypeNames(Constructor init)
get Constructor Signature With Long Type Names
return getSignature(init, true);