Call constructor. - Java Reflection

Java examples for Reflection:Constructor

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Description

Call constructor.

Demo Code

/*//from  w  w w .  j a  v  a 2  s.c  o m
 * NOTE: This is added by intellij IDE. Disregard this message if there is another copyright later in the file.
 * Copyright (C) 2014-2015  Will (n9Mtq4) Bresnahan
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
//package com.java2s;

import java.lang.reflect.Constructor;

public class Main {
    /**
     * Call constructor.
     *
     * @param clazz       the class
     * @param classParams the class params
     * @param params      the params
     * @return the object
     */
    public static <E> E callConstructor(Class clazz, Class[] classParams,
            Object[] params) {
        try {
            Constructor c = clazz.getDeclaredConstructor(classParams);
            c.setAccessible(true);
            return (E) c.newInstance(params);
        } catch (Exception e) {
            e.printStackTrace();
            return null;
        }
    }

    /**
     * Call constructor.
     *
     * @param clazz  the class
     * @param params the params
     * @return the object
     */
    public static <E> E callConstructor(Class clazz, Object... params) {
        return callConstructor(clazz, getClassParams(params), params);
    }

    /**
     * Get class params.
     *
     * @param params the params
     * @return the class [ ]
     */
    public static Class[] getClassParams(Object[] params) {
        Class[] classParams = new Class[params.length];
        for (int i = 0; i < classParams.length; i++) {
            classParams[i] = params[i].getClass();
        }
        return classParams;
    }
}

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