| /* |
| * 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. |
| */ |
| package org.apache.forrest.sourceexists; |
| |
| import java.net.MalformedURLException; |
| import java.util.Map; |
| |
| import java.io.IOException; |
| |
| import org.apache.cocoon.selection.Selector; |
| |
| import org.apache.avalon.framework.service.ServiceException; |
| import org.apache.avalon.framework.service.ServiceManager; |
| import org.apache.avalon.framework.service.Serviceable; |
| |
| import org.apache.avalon.framework.logger.AbstractLogEnabled; |
| import org.apache.avalon.framework.parameters.Parameters; |
| import org.apache.avalon.framework.thread.ThreadSafe; |
| |
| import org.apache.excalibur.source.Source; |
| import org.apache.excalibur.source.SourceResolver; |
| |
| /** |
| * Selects the first of a set of Sources that exists in the context. |
| * <p> |
| * For example, we could define a SourceExistsSelector with: |
| * <pre> |
| * <map:selector name="exists" |
| * logger="sitemap.selector.source-exists" |
| * src="org.apache.cocoon.selection.SourceExistsSelector" /> |
| * </pre> |
| * And use it to build a PDF from XSL:FO or a higher-level XML format with: |
| * |
| * <pre> |
| * <map:match pattern="**.pdf"> |
| * <map:select type="exists"> |
| * <map:when test="context/xdocs/{1}.fo"> |
| * <map:generate src="content/xdocs/{1}.fo" /> |
| * </map:when> |
| * <map:otherwise> |
| * <map:generate src="content/xdocs/{1}.xml" /> |
| * <map:transform src="stylesheets/document-to-fo.xsl" /> |
| * </map:otherwise> |
| * </map:select> |
| * <map:serialize type="fo2pdf" /> |
| * </pre> |
| */ |
| public class SourceExistsSelector extends AbstractLogEnabled |
| implements ThreadSafe, Selector, Serviceable { |
| |
| SourceResolver resolver = null; |
| |
| /** |
| * Set the current <code>ComponentManager</code> instance used by this |
| * <code>Composable</code>. |
| */ |
| public void service(ServiceManager manager) throws ServiceException { |
| this.resolver = (SourceResolver)manager.lookup(SourceResolver.ROLE); |
| } |
| |
| /** Return true if Source 'uri' resolves and exists. */ |
| public boolean select(String uri, Map objectModel, Parameters parameters) { |
| Source src = null; |
| |
| // The locationmap module will return null if there is no match for |
| // the supplied hint, without the following the URI will be resolved to |
| // the context root, which always exists, but does not contain a valid |
| // resource. |
| if (uri == null || uri == "") { |
| return false; |
| } |
| |
| try { |
| src = resolver.resolveURI(uri); |
| if (src.exists()) { |
| return true; |
| } else { |
| return false; |
| } |
| } catch (MalformedURLException e) { |
| getLogger().warn("Selector URL '"+uri+"' is not a valid Source URL"); |
| return false; |
| } catch (IOException e) { |
| getLogger().warn("Error reading from source '"+uri+"': "+e.getMessage()); |
| return false; |
| } finally { |
| resolver.release(src); |
| } |
| } |
| } |