/*
* Copyright (C) 2010 Google Inc.
*
* 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 com.google.clearsilver.jsilver.resourceloader;
import com.google.clearsilver.jsilver.exceptions.JSilverTemplateNotFoundException;
import java.io.File;
import java.io.FileInputStream;
import java.io.InputStreamReader;
import java.io.IOException;
import java.io.Reader;
/**
* Loads resources from a directory.
*
* @see ResourceLoader
*/
public class FileSystemResourceLoader extends BufferedResourceLoader {
private final File rootDir;
public FileSystemResourceLoader(File rootDir) {
this.rootDir = rootDir;
}
public FileSystemResourceLoader(String rootDir) {
this(new File(rootDir));
}
@Override
public Reader open(String name) throws IOException {
File file = new File(rootDir, name);
// Check for non-directory rather than is-file so that reads from
// e.g. pipes work.
if (file.exists() && !file.isDirectory() && file.canRead()) {
return buffer(new InputStreamReader(new FileInputStream(file), getCharacterSet()));
} else {
return null;
}
}
@Override
public Reader openOrFail(String name) throws JSilverTemplateNotFoundException, IOException {
Reader reader = open(name);
if (reader == null) {
throw new JSilverTemplateNotFoundException("No file '" + name + "' inside directory '"
+ rootDir + "'");
} else {
return reader;
}
}
/**
* Some applications, e.g. online help, need to know when a file has changed due to a symlink
* modification hence the use of {@link File#getCanonicalFile()}, if possible.
*/
@Override
public Object getResourceVersionId(String filename) {
File file = new File(rootDir, filename);
// Check for non-directory rather than is-file so that reads from
// e.g. pipes work.
if (file.exists() && !file.isDirectory() && file.canRead()) {
String fullPath;
try {
fullPath = file.getCanonicalPath();
} catch (IOException e) {
fullPath = file.getAbsolutePath();
}
return String.format("%s@%s", fullPath, file.lastModified());
} else {
return null;
}
}
}