Java Class New Instance newInstance(Class theClass, Object... initArgs)

Description

Create an object for the given class and initialize it from conf

License

Apache License

Parameter

Parameter	Description
theClass	class of which an object is created

Return

a new object

Declaration

@SuppressWarnings("unchecked")
public static <T> T newInstance(Class<T> theClass, Object... initArgs) 

Method Source Code

//package com.java2s;
/**// ww  w. j  ava2 s.  co  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;

import java.util.Map;
import java.util.concurrent.ConcurrentHashMap;

public class Main {
    private static final Class<?>[] EMPTY_CLASS_ARRAY = {};
    /**
     * Cache of constructors for each class. Pins the classes so they
     * can't be garbage collected until ReflectionUtils can be collected.
     */
    private static final Map<Class<?>, Constructor<?>> CONSTRUCTOR_CACHE = new ConcurrentHashMap<>();

    /**
     * Create an object for the given class and initialize it from conf
     *
     * @param theClass class of which an object is created
     * @return a new object
     */
    @SuppressWarnings("unchecked")
    public static <T> T newInstance(Class<T> theClass, Object... initArgs) {
        T result;
        try {
            Constructor<T> meth = (Constructor<T>) CONSTRUCTOR_CACHE
                    .get(theClass);
            if (meth == null) {
                meth = theClass.getDeclaredConstructor(EMPTY_CLASS_ARRAY);
                meth.setAccessible(true);
                CONSTRUCTOR_CACHE.put(theClass, meth);
            }
            result = meth.newInstance(initArgs);
        } catch (Exception e) {
            throw new RuntimeException(e);
        }
        return result;
    }
}

Related

1. newInstance(Class tClass, Object... initargs)
2. newInstance(Class theClass)
3. newInstance(Class theClass)
4. newInstance(Class theClass)
5. newInstance(Class theClass, Class[] parameterTypes, Object[] initargs)
6. newInstance(Class theClass, String className)
7. newInstance(Class theCls)
8. newInstance(Class type)
9. newInstance(Class type)