Create a new instance given a class name : Class Method Field Name « Reflection « Java

1. Java
2. Reflection
3. Class Method Field Name

Create a new instance given a class name

 
/*
 * 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.net.MalformedURLException;
import java.net.URL;

/**
 * A collection of class management utility methods.
 *
 * @version $Id: ClassUtils.java 587751 2007-10-24 02:41:36Z vgritsenko $
 */
public class ClassUtils {

    /**
     * Create a new instance given a class name
     *
     * @param className A class name
     * @return A new instance
     * @exception Exception If an instantiation error occurs
     */
    public static Object newInstance(String className) throws Exception {
        return loadClass(className).newInstance();
    }

    /**
     * Load a class given its name.
     * BL: We wan't to use a known ClassLoader--hopefully the heirarchy
     *     is set correctly.
     *
     * @param className A class name
     * @return The class pointed to by <code>className</code>
     * @exception ClassNotFoundException If a loading error occurs
     */
    public static Class loadClass(String className) throws ClassNotFoundException {
        return getClassLoader().loadClass(className);
    }

    /**
     * Return a resource URL.
     * BL: if this is command line operation, the classloading issues
     *     are more sane.  During servlet execution, we explicitly set
     *     the ClassLoader.
     *
     * @return The context classloader.
     * @exception MalformedURLException If a loading error occurs
     */
    public static URL getResource(String resource) throws MalformedURLException {
        return getClassLoader().getResource(resource);
    }

    /**
     * Return the context classloader.
     * BL: if this is command line operation, the classloading issues
     *     are more sane.  During servlet execution, we explicitly set
     *     the ClassLoader.
     *
     * @return The context classloader.
     */
    public static ClassLoader getClassLoader() {
        return Thread.currentThread().getContextClassLoader();
    }
}

   
  

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