Java Class New Instance newInstance(Class clazz)

Description

Create new instance.

License

Open Source License

Parameter

Parameter	Description
clazz	the class

Return

new instance

Declaration

public static <T> T newInstance(Class<T> clazz) 

Method Source Code

//package com.java2s;
/*//w  w w.ja v  a  2 s.co m
 * JBoss, Home of Professional Open Source.
 * Copyright 2011, Red Hat, Inc., and individual contributors
 * as indicated by the @author tags. See the copyright.txt file in the
 * distribution for a full listing of individual contributors.
 *
 * This is free software; you can redistribute it and/or modify it
 * under the terms of the GNU Lesser General Public License as
 * published by the Free Software Foundation; either version 2.1 of
 * the License, or (at your option) any later version.
 *
 * This software 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
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this software; if not, write to the Free
 * Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
 * 02110-1301 USA, or see the FSF site: http://www.fsf.org.
 */

import java.lang.reflect.Constructor;

public class Main {
    private static final Class[] EMPTY_CLASSES = new Class[0];
    private static final Object[] EMPTY_ARGS = new Object[0];

    /**
     * Create new instance.
     *
     * @param clazz the class
     * @return new instance
     */
    public static <T> T newInstance(Class<T> clazz) {
        return newInstance(clazz, EMPTY_CLASSES, EMPTY_ARGS);
    }

    /**
     * Create new instance.
     *
     * @param clazz the class
     * @param types the ctor types
     * @param args  the ctor args
     * @return new instance
     */
    public static <T> T newInstance(Class<T> clazz, Class[] types, Object[] args) {
        if (clazz == null)
            throw new IllegalArgumentException("Null class");

        try {
            Constructor<T> ctor = clazz.getDeclaredConstructor(types);
            ctor.setAccessible(true);
            return ctor.newInstance(args);
        } catch (Throwable t) {
            throw new RuntimeException(t);
        }
    }

    @SuppressWarnings("unchecked")
    public static <T> T newInstance(String className, Class[] types, Object[] args) {
        try {
            Class<?> clazz = Class.forName(className);
            return (T) newInstance(clazz, types, args);
        } catch (ClassNotFoundException e) {
            throw new RuntimeException(e);
        }
    }
}

Related

1. newInstance(Class classOf)
2. newInstance(Class clazz)
3. newInstance(Class clazz)
4. newInstance(Class clazz)
5. newInstance(Class clazz)
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7. newInstance(Class clazz)
8. newInstance(Class clazz)
9. newInstance(Class clazz)