io.atleon.util.Instantiation Maven / Gradle / Ivy
package io.atleon.util;
import java.lang.reflect.Constructor;
import java.lang.reflect.Modifier;
import java.util.Arrays;
import java.util.Collection;
import java.util.Map;
public final class Instantiation {
private Instantiation() {
}
public static T oneTyped(Class typeOrSubType, String qualifiedNameOfSubType, Object... parameters) {
return oneTyped(typeOrSubType, TypeResolution.classForQualifiedName(qualifiedNameOfSubType), parameters);
}
public static T oneTyped(Class typeOrSubType, Class subType, Object... parameters) {
if (typeOrSubType.isAssignableFrom(subType)) {
return typeOrSubType.cast(one(subType, parameters));
} else {
throw new IllegalArgumentException("Cannot instantiate type=" + typeOrSubType + " using subType=" + subType);
}
}
public static T one(Class clazz, Object... parameters) {
try {
Class[] parameterTypes = Arrays.stream(parameters)
.map(Instantiation::deduceParameterClass)
.toArray(Class[]::new);
Constructor constructor = clazz.getDeclaredConstructor(parameterTypes);
ensureConstructorAccessibility(constructor);
return constructor.newInstance(parameters);
} catch (Exception e) {
throw new IllegalArgumentException("Could not instantiate instance of Class: " + clazz, e);
}
}
private static Class deduceParameterClass(Object parameter) {
if (parameter instanceof Collection) {
return Collection.class;
} else {
return parameter instanceof Map ? Map.class : parameter.getClass();
}
}
private static void ensureConstructorAccessibility(Constructor constructor) {
if (!Modifier.isPublic(constructor.getModifiers()) && !constructor.isAccessible()) {
constructor.setAccessible(true);
}
}
}