io.github.selcukes.collections.Reflections Maven / Gradle / Ivy

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/*
 *  Copyright (c) Ramesh Babu Prudhvi.
 *
 *  Licensed under the Apache License, Version 2.0 (the "License");
 *  you may not use this file except in compliance with the License.
 *  You may obtain a copy of the License at
 *
 *         http://www.apache.org/licenses/LICENSE-2.0
 *
 *  Unless required by applicable law or agreed to in writing, software
 *  distributed under the License is distributed on an "AS IS" BASIS,
 *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *  See the License for the specific language governing permissions and
 *  limitations under the License.
 */

package io.github.selcukes.collections;

import lombok.SneakyThrows;
import lombok.experimental.UtilityClass;

import java.lang.reflect.Field;
import java.util.Arrays;

/**
 * Reflections is a class that provides a way to get a list of all the classes
 * in a package
 */
@UtilityClass
public class Reflections {
    /**
     * Creates a new instance of the class passed to it.
     *
     * @param  clazz                    the class to instantiate
     * @param  initArgs                 the arguments to pass to the constructor
     * @param                        the type of the class to instantiate
     * @return                          an instance of the class
     * @throws IllegalArgumentException if an error occurs while creating the
     *                                  instance
     */
    @SuppressWarnings("java:S3011")
    public static  T newInstance(final Class clazz, final Object... initArgs) {
        try {
            var constructor = clazz.getDeclaredConstructor(getClasses(initArgs));
            if (!constructor.canAccess(null)) {
                constructor.setAccessible(true);
            }
            return constructor.newInstance(initArgs);
        } catch (Exception e) {
            throw new IllegalArgumentException(e);
        }
    }

    /**
     * Sets the value of the field in the object.
     *
     * @param  object                   the object to modify
     * @param  fieldName                the name of the field to modify
     * @param  value                    the new value of the field
     * @throws IllegalArgumentException if an error occurs while setting the
     *                                  field
     */
    @SuppressWarnings("java:S3011")
    public static void setFieldValue(final Object object, final String fieldName, final Object value) {
        try {
            getField(object, fieldName).set(object, value);
        } catch (Exception e) {
            throw new IllegalArgumentException(e);
        }
    }

    /**
     * Returns the value of the specified field of the given object using
     * reflection.
     *
     * @param  object                   the object to get the field value from
     * @param  fieldName                the name of the field to get the value
     *                                  from
     * @return                          the value of the specified field
     * @throws IllegalArgumentException if the object is null or if the field
     *                                  cannot be accessed
     */
    @SuppressWarnings("java:S3011")
    public static Object getFieldValue(final Object object, final String fieldName) {
        try {
            return getField(object, fieldName).get(object);
        } catch (Exception e) {
            throw new IllegalArgumentException(e);
        }
    }

    @SneakyThrows
    @SuppressWarnings("squid:S3011")
    private static Field getField(final Object object, final String fieldName) {
        var clazz = object == null ? Object.class : object.getClass();
        var field = clazz.getDeclaredField(fieldName);
        field.setAccessible(true);
        return field;
    }

    /**
     * Invokes a method with the specified parameters on the specified object.
     *
     * @param  object     the object on which to invoke the method
     * @param  methodName the name of the method to invoke
     * @param  param      the parameters to pass to the method
     * @return            the result of the method invocation
     */
    @SuppressWarnings("squid:S3011")
    @SneakyThrows
    public static Object invokeMethod(final Object object, final String methodName, final Object... param) {
        var method = object.getClass().getDeclaredMethod(methodName, getClasses(param));
        method.setAccessible(true);
        return method.invoke(object, param);
    }

    /**
     * Invokes a static method with the specified parameters on the specified
     * class.
     *
     * @param  clazz      the class containing the static method
     * @param  methodName the name of the static method to invoke
     * @param  param      the parameters to pass to the method
     * @return            the result of the method invocation
     */
    @SuppressWarnings("squid:S3011")
    @SneakyThrows
    public static Object invokeStaticMethod(final Class clazz, final String methodName, final Object... param) {
        var method = clazz.getDeclaredMethod(methodName, getClasses(param));
        method.setAccessible(true);
        return method.invoke(null, param);
    }

    private Class[] getClasses(Object... objects) {
        return Arrays.stream(objects)
                .map(Object::getClass)
                .toArray(Class[]::new);
    }
}