Java Utililty Methods Assert Null

void assertAllAreNull(String messageIfNull, Object... objects)
Asserts that all of the objects are null.

for (final Object object : objects) {
 if (object != null) {
 throw new IllegalArgumentException(messageIfNull);

void assertInstance(final Object object, final Class c, final boolean allowNull)
Asserts the the given object is an instance of the given class -- optionally allowing the object to be null.

if (object == null && allowNull) {
 return;
if (object == null || c == null) {
 throw new NullPointerException();
} else if (!c.isInstance(object)) {
 throw new IllegalArgumentException();

void assertIsNull(Object obj)
Asserts that the passed entry is null

if (obj != null) {
 throw new AssertionError(
 "Passed object: " + obj.getClass().getName() + " is not null while this was expected");

T assertNonNull(final T object, final String paramName)
Throws NullPointerException with message paramName if object is null.

if (object == null) {
 throw new NullPointerException(paramName + " must not be null");
return object;

void assertNonNull(String argumentName, Object argument)
assert Non Null

if (argument == null)
 throw new IllegalArgumentException("Argument '" + argumentName + "' is null.");

void assertNoNull(Object object, String paramName)
Assert that the given object parameter is not null.

if (object == null) {
 throw new NullPointerException(paramName + " cannot be null.");

void assertNull(final Object obj, final String msg)
assert Null

if (null != obj) {
 throw new IllegalArgumentException(msg);

void assertNull(final Object value, final String name)
Asserts that the parameter's value is null.

if (value != null) {
 throw new IllegalArgumentException(PREFIX + name + " is not null.");

void assertNull(Object o)
assert Null

if (o != null) {
 throw new AssertionError("Not null.");

void assertNull(Object obj)
assert Null

if (obj != null) {
 throw new IllegalArgumentException();