wicket.contrib.groovy.GroovyWarClassLoader.java Source code

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Here is the source code for wicket.contrib.groovy.GroovyWarClassLoader.java

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/*
 * $Id: GroovyWarClassLoader.java 524 2006-01-08 09:30:40Z jdonnerstag $
 * $Revision: 524 $ $Date: 2006-01-08 01:30:40 -0800 (Sun, 08 Jan 2006) $
 * 
 * ==================================================================== 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 wicket.contrib.groovy;

import groovy.lang.GroovyClassLoader;

import java.io.IOException;
import java.io.InputStream;
import java.net.URL;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.codehaus.groovy.control.CompilationFailedException;

import wicket.util.string.Strings;

/**
 * I had some issues with the GroovyClassLoader (1.0.7-beta) which failed to
 * load a groovy files contained in the same war file. E.g.
 * 
 * <pre>
 *  wicket-examples.war!/web-inf/classes/groovy/A.groovy
 *  wicket-examples.war!/web-inf/classes/groovy/B.groovy
 * 
 *  public class A {
 *     public A() {
 *        B b = new B()
 *     }
 *  }
 * </pre>
 * 
 * GroovyClassLoader did not load Groovy class B.
 * 
 * @author Juergen Donnerstag
 */
public class GroovyWarClassLoader extends GroovyClassLoader {
    /** Logger */
    final private static Log log = LogFactory.getLog(GroovyWarClassLoader.class);

    /**
     * Constructor
     * 
     * @param loader
     *            The servlet's class loader
     */
    public GroovyWarClassLoader(ClassLoader loader) {
        super(loader);
    }

    /**
     * First try parent's implementation. If it fails, it'll throw a
     * ClassCastException. Catch it and than apply additional means to load the
     * class.
     * 
     * @param name
     *            Class name incl. package
     * @return The Class loaded, if found
     * @throws ClassNotFoundException,
     *             if class could not be loaded
     */
    protected Class findClass(final String name) throws ClassNotFoundException {
        try {
            // Try Groovies default implementation first
            return super.findClass(name);
        } catch (ClassNotFoundException ex) {
            log.debug("class name: " + name);

            // classname => filename
            String filename = Strings.replaceAll(name, ".", "/") + ".groovy";

            // File exists?
            final URL url = getResource(filename);
            if (url != null) {
                try {
                    // Get Groovy to parse the file and create the Class
                    final InputStream in = url.openStream();
                    if (in != null) {
                        Class clazz = parseClass(in);
                        if (clazz != null) {
                            return clazz;
                        }
                    } else {
                        log.warn("Groovy file not found: " + filename);
                    }
                } catch (CompilationFailedException e) {
                    throw new ClassNotFoundException("Error parsing groovy file: " + filename, e);
                } catch (IOException e) {
                    throw new ClassNotFoundException("Error reading groovy file: " + filename, e);
                } catch (Throwable e) {
                    throw new ClassNotFoundException("Error while reading groovy file: " + filename, e);
                }
            }

            throw ex;
        }
    }
}