WebAppPathResolver.java

/**
 *
 * Copyright 2015 Kamran Zafar
 *
 * 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.xeustechnologies.jcl.web;

import java.io.InputStream;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;
import java.util.Set;

import javax.servlet.ServletContext;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.xeustechnologies.jcl.utils.PathResolver;

/**
 * Resolves path to jar files and folder in a web application. The path must
 * starts with <b>webapp:</b>
 * 
 * @author Kamran
 * 
 */
public class WebAppPathResolver implements PathResolver {

    private final transient Logger logger = LoggerFactory.getLogger(WebAppPathResolver.class);

    private static final String JAR = ".jar";
    private static final String WEB_APP = "webapp:";
    private final ServletContext servletContext;

    public WebAppPathResolver(ServletContext servletContext) {
        this.servletContext = servletContext;
    }

    /**
     * Resolves path to jar files and folder in a web application
     * 
     * @see org.xeustechnologies.jcl.utils.PathResolver#resolvePath(java.lang.String)
     */
    @SuppressWarnings("unchecked")
    public Object[] resolvePath(String path) {
        if (path.startsWith( WEB_APP )) {
            String webpath = "/" + path.split( ":" )[1];

            if (isJar( webpath )) {
                logger.debug( "Found jar: {}", webpath );

                return new InputStream[] { servletContext.getResourceAsStream( webpath ) };
            }

            Set<String> paths = servletContext.getResourcePaths( webpath );

            if (paths.size() > 0) {
                Iterator<String> itr = paths.iterator();
                List<InputStream> streams = new ArrayList<InputStream>();

                while (itr.hasNext()) {
                    String source = itr.next();

                    if (isJar( source )) {
                        InputStream stream = servletContext.getResourceAsStream( source );

                        if (stream != null) {
                            logger.debug( "Found jar: {}", source );

                            streams.add( stream );
                        }
                    }
                }

                return streams.toArray( new InputStream[streams.size()] );
            }

        }

        return null;
    }

    private boolean isJar(String path) {
        return path.toLowerCase().endsWith( JAR );
    }
}