@Test
public void putAndGetInstance() {
// given
ClassToInstanceMap<Exception> map = MutableClassToInstanceMap.create();
// when
map.putInstance(RuntimeException.class, new RuntimeException());
map.putInstance(NullPointerException.class, new NullPointerException());
// then
assertThat(map.getInstance(RuntimeException.class), is(RuntimeException.class));
assertThat(map.getInstance(NullPointerException.class), is(NullPointerException.class));
}
/**
* Returns an arbitrary instance for {@code type}, or {@code null} if no arbitrary instance can be
* determined.
*/
@Nullable
public static <T> T get(Class<T> type) {
T defaultValue = DEFAULTS.getInstance(type);
if (defaultValue != null) {
return defaultValue;
}
Class<? extends T> implementation = getImplementation(type);
if (implementation != null) {
return get(implementation);
}
if (type.isEnum()) {
T[] enumConstants = type.getEnumConstants();
return (enumConstants.length == 0) ? null : enumConstants[0];
}
if (type.isArray()) {
return createEmptyArray(type);
}
T jvmDefault = Defaults.defaultValue(Primitives.unwrap(type));
if (jvmDefault != null) {
return jvmDefault;
}
if (Modifier.isAbstract(type.getModifiers()) || !Modifier.isPublic(type.getModifiers())) {
return arbitraryConstantInstanceOrNull(type);
}
final Constructor<T> constructor;
try {
constructor = type.getConstructor();
} catch (NoSuchMethodException e) {
return arbitraryConstantInstanceOrNull(type);
}
constructor.setAccessible(true); // accessibility check is too slow
try {
return constructor.newInstance();
} catch (InstantiationException impossible) {
throw new AssertionError(impossible);
} catch (IllegalAccessException impossible) {
throw new AssertionError(impossible);
} catch (InvocationTargetException e) {
logger.log(Level.WARNING, "Exception while invoking default constructor.", e.getCause());
return arbitraryConstantInstanceOrNull(type);
}
}
@Override
protected RpcConsumerRegistry createInstance(
final BindingToNormalizedNodeCodec codec, final ClassToInstanceMap<DOMService> delegates) {
final DOMRpcService domRpc = delegates.getInstance(DOMRpcService.class);
return new BindingDOMRpcServiceAdapter(domRpc, codec);
}
@Override
protected DataBroker createInstance(
final BindingToNormalizedNodeCodec codec, final ClassToInstanceMap<DOMService> delegates) {
final DOMDataBroker domDataBroker = delegates.getInstance(DOMDataBroker.class);
return new BindingDOMDataBrokerAdapter(domDataBroker, codec);
}
protected <T extends BrokerService> Optional<T> getGlobalService(final Class<T> service) {
return Optional.fromNullable(services.getInstance(service));
}
