ReflectionUtils.java

// Copyright 2016 Twitter. All rights reserved.
//
// 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 com.twitter.heron.spi.utils;

public final class ReflectionUtils {
  private ReflectionUtils() {

  }

  @SuppressWarnings("unchecked") // we don't know what T is until runtime
  public static <T> T newInstance(String className)
      throws ClassNotFoundException, InstantiationException, IllegalAccessException {
    return newInstance(ClassLoader.getSystemClassLoader(), className);
  }

  @SuppressWarnings("unchecked") // we don't know what T is until runtime
  public static <T> T newInstance(ClassLoader classLoader, String className)
      throws ClassNotFoundException, IllegalAccessException, InstantiationException {
    if (className == null) {
      throw new ClassNotFoundException("Can not instantiate class. className must not be null");
    }
    return (T) classLoader.loadClass(className).newInstance();
  }
}