ResourceUtils.java

/*
 * 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.asual.summer.core.util;

import java.io.File;
import java.io.FileInputStream;
import java.net.URL;
import java.net.URLDecoder;
import java.util.ArrayList;
import java.util.Collections;
import java.util.Comparator;
import java.util.Enumeration;
import java.util.HashMap;
import java.util.List;
import java.util.Locale;
import java.util.Map;
import java.util.jar.Manifest;

import javax.inject.Named;

import org.springframework.context.NoSuchMessageException;
import org.springframework.context.i18n.LocaleContextHolder;
import org.springframework.core.OrderComparator;

import com.asual.summer.core.resource.MessageResource;
import com.asual.summer.core.resource.PropertyResource;
import com.asual.summer.core.resource.ScriptResource;
import com.asual.summer.core.resource.StyleResource;

/**
 * 
 * @author Rostislav Hristov
 *
 */
@Named
public class ResourceUtils {
	
	private static Map<String, String> attributes = new HashMap<String, String>();
	
	private static List<MessageResource> messages = null;
	private static List<PropertyResource> properties = null;
	private static List<StyleResource> styles = null;
	private static List<ScriptResource> scripts = null;
	
	/** Constant for the file URL protocol.*/
    private static final String PROTOCOL_FILE = "file";
	
	public static String getMessage(String key) {
		return getMessage(key, new Object[] {}, LocaleContextHolder.getLocale());
	}
	
	public static String getMessage(String key, Locale locale) {
		return getMessage(key, new Object[] {}, locale);
	}

	public static String getMessage(String key, Object[] args) {
		return getMessage(key, args, LocaleContextHolder.getLocale());
	}
	
	public static String getMessage(String key, Object[] args, Locale locale) {
	
		if (messages == null) {
			messages = getResources(MessageResource.class);
		}
		
		if (messages != null) {
			for (MessageResource bean : messages) {
				try {
					return bean.getMessage(key, args, locale);
				} catch (NoSuchMessageException e) {
				}
			}
		}
		
		return null;
	}

	public static Object getProperty(String key) {
		
		if (properties == null) {
			properties = getResources(PropertyResource.class);
		}
		
		Object property = null;

		if (properties != null) {
			for (PropertyResource bean : properties) {
				property = bean.getProperty(key);
				if (property != null) {
					break;
				}
			}
		}
		
		if (property != null) {
			if (property instanceof String) {
				return ObjectUtils.convert((String) property);
			} else {
				return property;
			}
		}
		
		return null;
	}
	
	public static List<ScriptResource> getScripts() {
		if (scripts == null) {
			scripts = getResources(ScriptResource.class);
		}
		return scripts;
	}

	public static List<StyleResource> getStyles() {
		if (styles == null) {
			styles = getResources(StyleResource.class);
		}
		return styles;
	}
	
	public static String getManifestAttribute(String key) {
		try {
			if (!attributes.containsKey(key)) {
				String path = "META-INF/MANIFEST.MF";
				Manifest mf = new Manifest();
				URL resource = RequestUtils.getServletContext().getResource("/" + path);
				if (resource == null) {
					resource = getClasspathResources(path, false).get(0);
				}
				mf.read(new FileInputStream(resource.getFile()));
				attributes.put(key, mf.getMainAttributes().getValue(key));
			}
			return attributes.get(key);
		} catch (Exception e) {
			return "";
		}
	}
	
	public static boolean exists(String name) {
		return getClasspathResource(name) != null;
	}
	
	public static URL getClasspathResource(String name) {
		return getClasspathResource(name, true);
	}
	
	public static URL getClasspathResource(String name, boolean jarURL) {
		List<URL> list = getClasspathResources(name, jarURL);
		if (list.size() != 0) {
			return getClasspathResources(name, jarURL).get(0);
		}
		return null;
	}
	
	public static List<URL> getClasspathResources(String name) {
		return getClasspathResources(name, true);
	}
	
	public static List<URL> getClasspathResources(String name, boolean jarURL) {
		
		List<URL> list = new ArrayList<URL>();
		try {
			Enumeration<URL> resources = RequestUtils.class.getClassLoader().getResources(name);
			while(resources.hasMoreElements()) {
				URL resource = resources.nextElement();
				if (jarURL || jarURL == org.springframework.util.ResourceUtils.isJarURL(resource)) {
					list.add(resource);
				}
			}
		} catch (Exception e) {
		}
		
		Collections.sort(list, new Comparator<URL>() {
			
			private static final String PREFIX = "/summer-";
			
			public int compare(URL o1, URL o2) {
				return o1.getPath().indexOf(PREFIX) - o2.getPath().indexOf(PREFIX);
			}
			
		});
		
		return list;
	}

	@SuppressWarnings("unchecked")
	private static <T> List<T> getResources(Class<T> clazz) {
		
		String[] names = BeanUtils.getBeanNames(clazz);
		
		if (names != null) {
			List<T> resources = new ArrayList<T>();
			for (String name : names) {
				T bean = (T) BeanUtils.getBean(name);
				if (!resources.contains(bean)) {
					resources.add(bean);
				}
			}
			OrderComparator.sort(resources);
			return resources;			
		}
		
		return null;
	}
	
	/**
     * Tries to convert the specified URL to a file object. If this fails,
     * <b>null</b> is returned.
     *
     * @param url the URL
     * @return the resulting file object
     */
    @SuppressWarnings("deprecation")
	public static File fileFromURL(URL url)
    {
        if (PROTOCOL_FILE.equals(url.getProtocol()))
        {
            return new File(URLDecoder.decode(url.getPath()));
        }
        else
        {
            return null;
        }
    }
	
}