InternalAssets.java

/*
 *    Copyright 2012 Jason Miller
 *
 * 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 jj.server;

import java.nio.file.FileSystem;
import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.Paths;
import java.util.Iterator;
import java.util.Set;

import jj.ResourceResolver;

/**
 * provides implementation for finding assets in module jars
 * 
 * public because mockito requires it
 * 
 * @author jason
 *
 */
public abstract class InternalAssets {

	protected static final Path NOT_FOUND = Paths.get("/jj/not-found-sentinel/");
	
	private final ResourceResolver resolver;
	private final Set<String> paths;

	InternalAssets(
		final ResourceResolver resolver,
		final Set<String> paths
	) {
		this.resolver = resolver;
		this.paths = paths;
	}

	public Path path(String name) {
		Path result = null;
		try {
			Iterator<String> iterator = paths.iterator();
			while (result == null && iterator.hasNext()) {
				String candidate = iterator.next();
				candidate = candidate + (candidate.endsWith("/") ? "" : "/") + name;
				Path path = resolver.pathForFile(candidate);
				if (path != null && Files.exists(path)) {
					result = path;
				}
			}
		} catch (Exception e) {
			e.printStackTrace();
		}
		
		// this is sort of an ugly solution but we have to return a path that doesn't
		// exist so we can be happy
		if (result == null) {
			result = NOT_FOUND;
		}
		
		return result.normalize().toAbsolutePath();
	}
}