package liquibase.integration.commandline;

 import liquibase.resource.ResourceAccessor;

 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;

 /**

  * Implementation of liquibase.FileOpener for the command line app.

  * 

  * @see liquibase.resource.ResourceAccessor

  */

 public class CommandLineResourceAccessor implements ResourceAccessor {

     private ClassLoader loader;

     public CommandLineResourceAccessor(ClassLoader loader) {

         this.loader = loader;

     }

     public InputStream getResourceAsStream(String file) throws IOException {

         URL resource = loader.getResource(file);

         if (resource == null) {

             throw new IOException(file + " could not be found");

         }

         return resource.openStream();

     }

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

         return loader.getResources(packageName);

     }

     public ClassLoader toClassLoader() {

         return loader;

     }

     @Override

     public String toString() {

         String description;

         if (loader instanceof URLClassLoader) {

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

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

                 urls.add(url.toExternalForm());

             }

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

         } else {

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

         }

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

     }

 }