EgovObjectUtil.java

/*
 * Copyright 2008-2009 MOPAS(Ministry of Public Administration and Security).
 *
 * 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 egovframework.rte.fdl.string;

import java.lang.reflect.Constructor;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/**
 * 객체의 로딩을 지원하는 유틸 클래스
 * 
 * <p><b>NOTE:</b> Class 로딩 등의 객체관련 기능을 제공하는 유틸이다.</p>
 * 
 * @author 실행환경 개발팀 윤성종
 * @since 2009.06.01
 * @version 1.0
 * @see <pre>
 *  == 개정이력(Modification Information) ==
 *
 *   수정일      수정자           수정내용
 *  -------    --------    ---------------------------
 *   2009.06.01  윤성종           최초 생성
 *
 * </pre>
 */
public final class EgovObjectUtil {

	private static final Logger LOGGER = LoggerFactory.getLogger(EgovObjectUtil.class);

    private EgovObjectUtil() {

    }

    /**
     * 클래스명으로 객체를 로딩한다.
     * 
     * @param className
     * @return
     * @throws ClassNotFoundException
     * @throws Exception
     */
	public static Class<?> loadClass(String className) throws ClassNotFoundException, Exception {

		Class<?> clazz = Thread.currentThread().getContextClassLoader().loadClass(className);

		if (clazz == null) {
			clazz = Class.forName(className);
		}

		return clazz;
	}

    /**
     * 클래스명으로 객체를 로드한 후 인스턴스화 한다.
     * 
     * @param className
     * @return
     * @throws ClassNotFoundException
     * @throws InstantiationException
     * @throws IllegalAccessException
     * @throws Exception
     */
	public static Object instantiate(String className) throws ClassNotFoundException, InstantiationException, IllegalAccessException, Exception {
		Class<?> clazz;

		try {
			clazz = loadClass(className);
			return clazz.newInstance();
		} catch (ClassNotFoundException e) {
			LOGGER.error("{} : Class is can not instantialized.", className);
			throw new ClassNotFoundException();
		} catch (InstantiationException e) {
			LOGGER.error("{} : Class is can not instantialized.", className);
			throw new InstantiationException();
		} catch (IllegalAccessException e) {
			LOGGER.error("{} : Class is not accessed.", className);
			throw new IllegalAccessException();
		} catch (Exception e) {
			LOGGER.error("{} : Class is not accessed.", className);
			throw new Exception(e);
		}
	}

    /**
     * 클래스명으로 파라매터가 있는 클래스의 생성자를 인스턴스화 한다.
     * 예) Class <?> clazz = EgovObjectUtil.loadClass(this.mapClass);
     * Constructor <?> constructor = clazz.getConstructor(new Class[]{DataSource.class, String.class});
     * Object [] params = new Object [] {
     *     getDataSource(), getUsersByUsernameQuery()
     *  };
     * this.usersByUsernameMapping = (EgovUsersByUsernameMapping)constructor.newInstance(params);
     * 
     * @param className
     * @return
     * @throws ClassNotFoundException
     * @throws InstantiationException
     * @throws IllegalAccessException
     * @throws Exception
     */
	public static Object instantiate(String className, String[] types, Object[] values) throws ClassNotFoundException, InstantiationException, IllegalAccessException, Exception {
		Class<?> clazz;
		Class<?>[] classParams = new Class[values.length];
		Object[] objectParams = new Object[values.length];

		try {
			clazz = loadClass(className);

			for (int i = 0; i < values.length; i++) {
				classParams[i] = loadClass(types[i]);
				objectParams[i] = values[i];
			}

			Constructor<?> constructor = clazz.getConstructor(classParams);
			return constructor.newInstance(values);

		} catch (ClassNotFoundException e) {
			LOGGER.error("{} : Class is can not instantialized.", className);
			throw new ClassNotFoundException();
		} catch (InstantiationException e) {
			LOGGER.error("{} : Class is can not instantialized.", className);
			throw new InstantiationException();
		} catch (IllegalAccessException e) {
			LOGGER.error("{} : Class is not accessed.", className);
			throw new IllegalAccessException();
		} catch (Exception e) {
			LOGGER.error("{} : Class is not accessed.", className);
			throw new Exception(e);
		}
	}

    /**
     * 객체가 Null 인지 확인한다.
     * 
     * @param object
     * @return Null인경우 true / Null이 아닌경우 false
     */
    public static boolean isNull(Object object) {
        return ((object == null) || object.equals(null));
    }
}