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Small utilities and convenience wrappers.
There is a newer version: 2022.05.01-7057
package com.brambolt.lang.reflect;

import java.lang.reflect.Constructor;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;

/**
 * Porcelain for single line reflection without declared exceptions.
 */
public class Reflection {

    /**
     * Instantiates an object of the parameter class with the default constructor.
     *
     * @param  The type of the object to instantiate
     * @param className The class to instantiate
     * @param description The description to prefix exception messages with
     * @return The instantiated object
     * @throws IllegalStateException In case instantiation fails
     */
    public static  T instantiate(String className, String description) {
        return instantiate(className, new Class[] {}, new Object[] {}, description);
    }

    /**
     * Instantiates an object of the parameter class with the constructor
     * identified by the parameter types, using the parameter objects.
     *
     * @param  The type of the object to instantiate
     * @param className The class to instantiate
     * @param parameterTypes The parameter types of the constructor to use
     * @param parameters The parameter objects to pass
     * @param description The description to prefix exception messages with
     * @return The instantiated object
     * @throws IllegalStateException In case instantiation fails
     */
    public static  T instantiate(
        String className, Class[] parameterTypes, Object[] parameters, String description) {
        try {
            @SuppressWarnings("unchecked")
            Class clss = (Class) Class.forName(className);
            Constructor constructor = clss.getConstructor(parameterTypes);
            return constructor.newInstance(parameters);
        } catch (ClassNotFoundException x) {
            throw new IllegalStateException(
                description + " class [" + className + "] not available", x);
        } catch (NoSuchMethodException x) {
            throw new IllegalStateException("" +
                description + " constructor [" + className + "] not available", x);
        } catch (IllegalAccessException | InstantiationException | InvocationTargetException x) {
            throw new IllegalStateException(
                description + " [" + className + "] not instantiated", x);
        }
    }

    /**
     * Invokes a static method on a class as identified by the parameters.
     *
     * @param  The return type for the method to invoke
     * @param className The class to invoke
     * @param methodName The static method to invoke
     * @param parameterTypes The parameter types of the method
     * @param parameters The parameter objects to pass to the method
     * @param description The description to prefix exception messages with
     * @return The return value
     * @throws IllegalArgumentException If one or more parameters are missing
     * @throws IllegalStateException In case invocation fails
     */
    public static  T invoke(
        String className, String methodName,
        Class[] parameterTypes, Object[] parameters,
        String description) {
        return invoke(className, methodName, null, parameterTypes, parameters, description);
    }


    /**
     * Invokes a method on an object as identified by the parameters.
     *
     * @param  The return type for the method to invoke
     * @param className The class of the object to invoke
     * @param methodName The method to invoke
     * @param object The object to dispatch the method on
     * @param parameterTypes The parameter types of the constructor to use
     * @param parameters The parameter objects to pass
     * @param description The description to prefix exception messages with
     * @return The instantiated object
     * @throws IllegalArgumentException If one or more parameters are missing
     * @throws IllegalStateException In case instantiation fails
     */
    public static  T invoke(
        String className, String methodName, Object object,
        Class[] parameterTypes, Object[] parameters,
        String description) {
        if (null == className || className.trim().isEmpty())
            throw new IllegalArgumentException("No class name provided");
        if (null == methodName || methodName.trim().isEmpty())
            throw new IllegalArgumentException("No method name provided");
        try {
            Class clss = Class.forName(className);
            Method method = clss.getDeclaredMethod(methodName, parameterTypes);
            //noinspection unchecked
            return (T) method.invoke(object, parameters);
        } catch (ClassNotFoundException x) {
            throw new IllegalStateException(
                description + " class [" + className + "] not available", x);
        } catch (NoSuchMethodException x) {
            throw new IllegalStateException("" +
                description + " constructor [" + className + "] not available", x);
        } catch (IllegalAccessException | InvocationTargetException x) {
            throw new IllegalStateException(
                description + " [" + className + "] not instantiated", x);
        }
    }
}