diff options
Diffstat (limited to 'velocity-engine-core/src/main/java/org/apache/velocity/runtime/resource/loader/URLResourceLoader.java')
| -rw-r--r-- | velocity-engine-core/src/main/java/org/apache/velocity/runtime/resource/loader/URLResourceLoader.java | 214 |
1 files changed, 214 insertions, 0 deletions
diff --git a/velocity-engine-core/src/main/java/org/apache/velocity/runtime/resource/loader/URLResourceLoader.java b/velocity-engine-core/src/main/java/org/apache/velocity/runtime/resource/loader/URLResourceLoader.java new file mode 100644 index 00000000..81fe33b9 --- /dev/null +++ b/velocity-engine-core/src/main/java/org/apache/velocity/runtime/resource/loader/URLResourceLoader.java @@ -0,0 +1,214 @@ +package org.apache.velocity.runtime.resource.loader; + +/* + * 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 org.apache.commons.lang3.StringUtils; +import org.apache.velocity.exception.ResourceNotFoundException; +import org.apache.velocity.runtime.resource.Resource; +import org.apache.velocity.util.ExtProperties; + +import java.io.IOException; +import java.io.InputStream; +import java.io.Reader; +import java.net.URL; +import java.net.URLConnection; +import java.util.HashMap; +import java.util.Map; + +/** + * This is a simple URL-based loader. + * + * @author <a href="mailto:geirm@apache.org">Geir Magnusson Jr.</a> + * @author <a href="mailto:nbubna@apache.org">Nathan Bubna</a> + * @version $Id: URLResourceLoader.java 191743 2005-06-21 23:22:20Z dlr $ + * @since 1.5 + */ +public class URLResourceLoader extends ResourceLoader +{ + private String[] roots = null; + protected Map<String, String> templateRoots = null; + private int timeout = -1; + + /** + * @param configuration + * @see ResourceLoader#init(org.apache.velocity.util.ExtProperties) + */ + @Override + public void init(ExtProperties configuration) + { + log.trace("URLResourceLoader: initialization starting."); + + roots = configuration.getStringArray("root"); + if (log.isDebugEnabled()) + { + for (String root : roots) + { + log.debug("URLResourceLoader: adding root '{}'", root); + } + } + + timeout = configuration.getInt("timeout", -1); + + // init the template paths map + templateRoots = new HashMap<>(); + + log.trace("URLResourceLoader: initialization complete."); + } + + /** + * Get a Reader so that the Runtime can build a + * template with it. + * + * @param name name of template to fetch bytestream of + * @param encoding asked encoding + * @return InputStream containing the template + * @throws ResourceNotFoundException if template not found + * in the file template path. + * @since 2.0 + */ + @Override + public synchronized Reader getResourceReader(String name, String encoding) + throws ResourceNotFoundException + { + if (StringUtils.isEmpty(name)) + { + throw new ResourceNotFoundException("URLResourceLoader: No template name provided"); + } + + Reader reader = null; + Exception exception = null; + for (String root : roots) + { + InputStream rawStream = null; + try + { + URL u = new URL(root + name); + URLConnection conn = u.openConnection(); + conn.setConnectTimeout(timeout); + conn.setReadTimeout(timeout); + rawStream = conn.getInputStream(); + reader = buildReader(rawStream, encoding); + + if (reader != null) + { + log.debug("URLResourceLoader: Found '{}' at '{}'", name, root); + + // save this root for later re-use + templateRoots.put(name, root); + break; + } + } + catch (IOException ioe) + { + if (rawStream != null) + { + try + { + rawStream.close(); + } + catch (IOException e) + { + } + } + log.debug("URLResourceLoader: Exception when looking for '{}' at '{}'", name, root, ioe); + + // only save the first one for later throwing + if (exception == null) + { + exception = ioe; + } + } + } + + // if we never found the template + if (reader == null) + { + String msg; + if (exception == null) + { + msg = "URLResourceLoader: Resource '" + name + "' not found."; + } + else + { + msg = exception.getMessage(); + } + // convert to a general Velocity ResourceNotFoundException + throw new ResourceNotFoundException(msg); + } + + return reader; + } + + /** + * Checks to see if a resource has been deleted, moved or modified. + * + * @param resource Resource The resource to check for modification + * @return boolean True if the resource has been modified, moved, or unreachable + */ + @Override + public boolean isSourceModified(Resource resource) + { + long fileLastModified = getLastModified(resource); + // if the file is unreachable or otherwise changed + return fileLastModified == 0 || + fileLastModified != resource.getLastModified(); + } + + /** + * Checks to see when a resource was last modified + * + * @param resource Resource the resource to check + * @return long The time when the resource was last modified or 0 if the file can't be reached + */ + @Override + public long getLastModified(Resource resource) + { + // get the previously used root + String name = resource.getName(); + String root = templateRoots.get(name); + + try + { + // get a connection to the URL + URL u = new URL(root + name); + URLConnection conn = u.openConnection(); + conn.setConnectTimeout(timeout); + conn.setReadTimeout(timeout); + return conn.getLastModified(); + } + catch (IOException ioe) + { + // the file is not reachable at its previous address + String msg = "URLResourceLoader: '"+name+"' is no longer reachable at '"+root+"'"; + log.error(msg, ioe); + throw new ResourceNotFoundException(msg, ioe, rsvc.getLogContext().getStackTrace()); + } + } + + /** + * Returns the current, custom timeout setting. If negative, there is no custom timeout. + * @return timeout + * @since 1.6 + */ + public int getTimeout() + { + return timeout; + } +} |