package liquibase.resource;

 import liquibase.util.StringUtils;

 import java.io.IOException;

 import java.io.InputStream;

 import java.net.URL;

 import java.net.URLClassLoader;

 import java.util.ArrayList;

 import java.util.Enumeration;

 import java.util.List;

 /**

  * An implementation of liquibase.FileOpener that opens file from the class loader.

  * 

  * @see ResourceAccessor

  */

 public class ClassLoaderResourceAccessor implements ResourceAccessor {

     private ClassLoader classLoader;

     public ClassLoaderResourceAccessor() {

         this.classLoader = getClass().getClassLoader();

     }

     public ClassLoaderResourceAccessor(ClassLoader classLoader) {

         this.classLoader = classLoader;

     }

     public InputStream getResourceAsStream(String file) throws IOException {

         return classLoader.getResourceAsStream(file);

     }

     public Enumeration<URL> getResources(String packageName) throws IOException {

         return classLoader.getResources(packageName);

     }

     public ClassLoader toClassLoader() {

         return classLoader;

     }

     @Override

     public String toString() {

         String description;

         if (classLoader instanceof URLClassLoader) {

             List<String> urls = new ArrayList<String>();

             for (URL url : ((URLClassLoader) classLoader).getURLs()) {

                 urls.add(url.toExternalForm());

             }

             description = StringUtils.join(urls, ",");

         } else {

             description = classLoader.getClass().getName();

         }

         return getClass().getName() + "(" + description + ")";

     }

 }