ServletContextLoader.java

/*
 * JBoss, Home of Professional Open Source
 * Copyright 2011, Red Hat, Inc. and/or its affiliates, and individual
 * contributors by the @authors tag. See the copyright.txt in the
 * distribution for a full listing of individual contributors.
 *
 * 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 org.jboss.solder.resourceLoader.servlet;

import java.io.InputStream;
import java.net.MalformedURLException;
import java.net.URL;
import java.util.Collection;
import java.util.Set;

import javax.servlet.ServletContext;

import org.jboss.solder.resourceLoader.ResourceLoader;

import static java.util.Collections.emptySet;
import static java.util.Collections.singleton;

/**
 * Implementation of ResourceLoader that can load from the servlet context. It
 * is not used directly but is called by DelegatingResourceLoader
 *
 * @author stuart
 */
class ServletContextLoader implements ResourceLoader {

    private final ServletContext context;

    ServletContextLoader(ServletContext context) {
        this.context = context;
    }

    public URL getResource(String resource) {
        if (!resource.startsWith("/")) {
            resource = "/" + resource;
        }
        try {
            return context.getResource(resource);
        } catch (MalformedURLException e) {
            throw new RuntimeException(e);
        }
    }

    public InputStream getResourceAsStream(String resource) {
        if (!resource.startsWith("/")) {
            resource = "/" + resource;
        }
        return context.getResourceAsStream(resource);
    }

    public Set<URL> getResources(String name) {
        URL resource = getResource(name);
        if (resource != null) {
            return singleton(resource);
        }
        return emptySet();
    }

    public Collection<InputStream> getResourcesAsStream(String name) {
        InputStream resource = getResourceAsStream(name);
        if (resource != null) {
            return singleton(resource);
        } else {
            return emptySet();
        }
    }

    /**
     * <p>
     * This loader has precedence 5, and so is searched after the classpath.
     * </p>
     *
     * @return a precedence of 5
     */
    // NB This is currently not used due to the interference of DelegatingResourceLoader
    public int getPrecedence() {
        return 5;
    }

    @Override
    public String toString() {
        return getClass().getName() + " [" + context.getContextPath() + "]";
    }

}