// Copyright (c) 2000 Just Objects B.V. <just@justobjects.nl>// Distributable under LGPL license. See terms of license at gnu.org.package nl.justobjects.pushlet.util;import java.io.FileInputStream;import java.io.IOException;import java.text.CharacterIterator;import java.text.StringCharacterIterator;import java.util.Properties;/** * Utilities that interact with the underlying OS/JVM. * * @author Just van den Broecke * @version $Id: Sys.java,v 1.4 2007/11/10 14:17:18 justb Exp $ */public class Sys {	/**	 * Replace characters having special meaning <em>inside</em> HTML tags	 * with their escaped equivalents, using character entities such as <tt>'&amp;'</tt>.	 * <p/>	 * <P>The escaped characters are :	 * <ul>	 * <li> <	 * <li> >	 * <li> "	 * <li> '	 * <li> \	 * <li> &	 * </ul>	 * <p/>	 * <P>This method ensures that arbitrary text appearing inside a tag does not "confuse"	 * the tag. For example, <tt>HREF='Blah.do?Page=1&Sort=ASC'</tt>	 * does not comply with strict HTML because of the ampersand, and should be changed to	 * <tt>HREF='Blah.do?Page=1&amp;Sort=ASC'</tt>. This is commonly seen in building	 * query strings. (In JSTL, the c:url tag performs this task automatically.)	 */	static public String forHTMLTag(String aTagFragment) {		final StringBuffer result = new StringBuffer();		final StringCharacterIterator iterator = new StringCharacterIterator(aTagFragment);		char character = iterator.current();		while (character != CharacterIterator.DONE) {			if (character == '<') {				result.append("&lt;");			} else if (character == '>') {				result.append("&gt;");			} else if (character == '\"') {				result.append("&quot;");			} else if (character == '\'') {				result.append("&#039;");			} else if (character == '\\') {				result.append("&#092;");			} else if (character == '&') {				result.append("&amp;");			} else {				//the char is not a special one				//add it to the result as is				result.append(character);			}			character = iterator.next();		}		return result.toString();	}	/**	 * Load properties file from classpath.	 */	static public Properties loadPropertiesResource(String aResourcePath) throws IOException {		try {			// Use the class loader that loaded our class.			// This is required where for reasons like security			// multiple class loaders exist, e.g. BEA WebLogic.			// Thanks to Lutz Lennemann 29-aug-2000.			ClassLoader classLoader = Sys.class.getClassLoader();			Properties properties = new Properties();			// Try loading it.			properties.load(classLoader.getResourceAsStream(aResourcePath));			return properties;		} catch (Throwable t) {			throw new IOException("failed loading Properties resource from " + aResourcePath);		}	}	/**	 * Load properties file from file path.	 */	static public Properties loadPropertiesFile(String aFilePath) throws IOException {		try {			Properties properties = new Properties();			// Try loading it.			properties.load(new FileInputStream(aFilePath));			return properties;		} catch (Throwable t) {			throw new IOException("failed loading Properties file from " + aFilePath);		}	}	/**	 * Shorthand for current time.	 */	static public long now() {		return System.currentTimeMillis();	}}