ClassResourceLoader.java

Violations

Source code

/*
 * hgcommons 9
 * Hammurapi Group Common Library
 * Copyright (C) 2003  Hammurapi Group
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2 of the License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 *
 * URL: http://www.hammurapi.biz/hammurapi-biz/ef/xmenu/hammurapi-group/products/products/hgcommons/index.html
 * e-Mail: support@hammurapi.biz
 */
package biz.hammurapi.util;

import java.io.IOException;
import java.io.InputStream;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Iterator;
import java.util.Locale;
import java.util.Map;
import java.util.Properties;

import biz.hammurapi.config.ConfigurationException;
import biz.hammurapi.config.Context;
import biz.hammurapi.config.DomConfigFactory;
import biz.hammurapi.config.RuntimeConfigurationException;

/**
 * Utility class which searches class hierarchy for a resource.
 * Resource shall be named after class name, profile name is separated from
 * class name by ! and locale separated from class name/profile by _.
 * @author Pavel Vlasov
 * @revision $Revision$
 */
public class ClassResourceLoader {
	private Visitable visitable;
	private Class clazz;
	
	/**
	 *
	 */
	public ClassResourceLoader(Class clazz) {
		this.visitable=new ClassHierarchyVisitable(clazz);
		this.clazz=clazz;
	}
	
	/**
	 *
	 * @param profile Profile, can be null
	 * @param extension Extension, can be null
	 * @return
	 */
	public InputStream getResourceAsStream(String profile, String extension) {
		return getResourceAsStream(profile, Locale.getDefault(), extension);
	}

	/**
	 * @param profile
	 * @param extension
	 * @return
	 */
	public InputStream getResourceAsStream(final String profile, final Locale locale, final String extension) {		
		final InputStream[] ret={null};
		visitable.accept(new Visitor() {
			Locale actualLocale = locale==null ? Locale.getDefault() : locale;

			public boolean visit(Object target) {
				Class currentClass=(Class) target;
				for (int i=0; i<4; i++) {
					String variant=currentClass.getName().replace('.','/');
					if (profile!=null) {
						variant+="!"+profile;
					}
					
					switch (i) {
						case 0:
							variant+="_"+actualLocale;
							break;
						case 1:
							variant+="_"+actualLocale.getLanguage();
							if (actualLocale.getCountry().length()!=0) {
								variant+="_"+actualLocale.getCountry();
							}
							break;
						case 2:
							variant+="_"+actualLocale.getLanguage();
							break;
						case 3:
							break;							
					}
					
					if (extension!=null) {
						variant+="."+extension;
					}
					
					
					ret[0]=clazz.getClassLoader().getResourceAsStream(variant);
					if (ret[0]!=null) {
						return false;
					}
				}
															
				return true;
			}
			
		});
		
		return ret[0];
	}

	/**
	 *
	 * @param profile Profile, can be null
	 * @param extension Extension, can be null
	 * @return
	 */
	public Properties getProperties(String profile, String extension) {
		return getProperties(profile, Locale.getDefault(), extension);
	}

	/**
	 * @param profile
	 * @param extension
	 * @return
	 */
	public Properties getProperties(final String profile, final Locale locale, final String extension) {
		final Properties ret=new Properties();
		visitable.accept(new Visitor() {

			public boolean visit(Object target) {
				Class currentClass=(Class) target;
				for (int i=0; i<4; i++) {
					String variant=currentClass.getName().replace('.','/');
					if (profile!=null) {
						variant+=profile;
					}
					
					switch (i) {
						case 0:
							variant+="_"+locale;
							break;
						case 1:
							variant+="_"+locale.getLanguage();
							if (locale.getCountry().length()!=0) {
								variant+="_"+locale.getCountry();
							}
							break;
						case 2:
							variant+="_"+locale.getLanguage();
							break;
						case 3:
							break;							
					}
					
					if (extension!=null) {
						variant+="."+extension;
					}
					
					
					InputStream s=clazz.getClassLoader().getResourceAsStream(variant);
					if (s!=null) {
						Properties cp=new Properties();
						try {
							cp.load(s);
							Iterator it=cp.entrySet().iterator();
							while (it.hasNext()) {
								Map.Entry entry=(Map.Entry) it.next();
								if (!ret.containsKey(entry.getKey())) {
									ret.setProperty((String) entry.getKey(), (String) entry.getValue());
								}
							}
						} catch (IOException e) {
							throw new RuntimeConfigurationException("Cannot load properties from resource "+variant, e);
						}
						
						break;
					}
				}
				
											
				return true;
			}
			
		});
		
		return ret;
	}
	
	/**
	 * @param profile
	 * @param extension
	 * @return
	 */
	public Context getContext(final String profile, Locale locale, final String extension) {
		final Locale actualLocale = locale==null ? Locale.getDefault() : locale;
		final Collection contexts=new ArrayList();
		final DomConfigFactory dcf=new DomConfigFactory();
		visitable.accept(new Visitor() {

			public boolean visit(Object target) {
				Class currentClass=(Class) target;
				for (int i=0; i<4; i++) {
					String variant=currentClass.getName().replace('.','/');
					if (profile!=null) {
						variant+=profile;
					}
					
					switch (i) {
						case 0:
							variant+="_"+actualLocale;
							break;
						case 1:
							variant+="_"+actualLocale.getLanguage();
							if (actualLocale.getCountry().length()!=0) {
								variant+="_"+actualLocale.getCountry();
							}
							break;
						case 2:
							variant+="_"+actualLocale.getLanguage();
							break;
						case 3:
							break;							
					}
					
					if (extension!=null) {
						variant+="."+extension;
					}
					
					
					InputStream s=clazz.getClassLoader().getResourceAsStream(variant);
					if (s!=null) {
						try {
							contexts.add(dcf.create(s, null));
						} catch (ConfigurationException e) {
							throw new RuntimeConfigurationException(e);
						} catch (IOException e) {
							throw new RuntimeConfigurationException(e);
						}
						break;
					}
				}
															
				return true;
			}
			
		});
		
		return contexts.isEmpty() ? null : new Context() {

			public Object get(String name) {
				Iterator it=contexts.iterator();
				while (it.hasNext()) {
					Object ret=((Context) it.next()).get(name);
					if (ret!=null) {
						return ret;
					}
				}
				return null;
			}
			
		};
	}	
}