Java Class New Instance newInstance(Class<T> klass, Object... args)

Description

Uses the constructor represented by this Constructor object to create and initialize a new instance of the constructor's declaring class, with the specified initialization parameters.

License

Apache License

Parameter

Parameter	Description
T	type for the new instance
klass	the Class object.
args	array of objects to be passed as arguments to the constructor call.

Return

a new object created by calling the constructor this object represents.

Declaration

public static <T> T newInstance(Class<T> klass, Object... args)

Method Source Code

//package com.java2s;
/**//from  www .  java 2s .  c o m
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you 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.
 */

import java.lang.reflect.Constructor;

public class Main {
    /**
     * Uses the constructor represented by this {@code Constructor} object to
     * create and initialize a new instance of the constructor's declaring
     * class, with the specified initialization parameters.
     *
     * @param <T> type for the new instance
     * @param klass the Class object.
     * @param args array of objects to be passed as arguments to the constructor
     *        call.
     * @return a new object created by calling the constructor this object
     *         represents.
     */
    public static <T> T newInstance(Class<T> klass, Object... args) {
        try {
            Constructor<T> ctor;

            if (args.length == 0) {
                ctor = klass.getDeclaredConstructor();
            } else {
                Class<?>[] argClses = new Class[args.length];
                for (int i = 0; i < args.length; i++) {
                    argClses[i] = args[i].getClass();
                }
                ctor = klass.getDeclaredConstructor(argClses);
            }
            ctor.setAccessible(true);
            return ctor.newInstance(args);
        } catch (Exception e) {
            throw new RuntimeException(e);
        }
    }
}

Java Class New Instance newInstance(Class klass, Object... args)