Here you can find the source of getProperty(String propertyName)
| Parameter | Description |
|---|---|
| propertyName | The name of property. |
public static String getProperty(String propertyName)
//package com.java2s; /* MOD_V2.0/*from w ww .j ava 2 s.c o m*/ * Copyright (c) 2012 OpenDA Association * All rights reserved. * * This file is part of OpenDA. * * OpenDA 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 3 of * the License, or (at your option) any later version. * * OpenDA 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 OpenDA. If not, see <http://www.gnu.org/licenses/>. */ import java.io.File; import java.io.IOException; import java.net.URL; public class Main { /** Get the specified property from the environment. An empty string * is returned if the argument environment variable does not exist, * though if certain properties are not defined, then we * make various attempts to determine them and then set them. * See the javadoc page for java.util.System.getProperties() for * a list of system properties. * <p>The following properties are handled specially * <dl> * <dt> "ptolemy.ptII.dir" * <dd> vergil usually sets the ptolemy.ptII.dir property to the * value of $PTII. However, if we are running under Web Start, * then this property might not be set, in which case we look * for "ptolemy/kernel/util/NamedObj.class" and set the * property accordingly. * <dt> "ptolemy.ptII.dirAsURL" * <dd> Return $PTII as a URL. For example, if $PTII was c:\ptII, * then return file:/c:/ptII/. * <dt> "user.dir" * <dd> Return the canonical path name to the current working directory. * This is necessary because under JDK1.4.1 System.getProperty() * returns <code><b>c</b>:/<i>foo</i></code> * whereas most of the other methods that operate * on path names return <code><b>C</b>:/<i>foo</i></code>. * </dl> * @param propertyName The name of property. * @return A String containing the string value of the property. */ public static String getProperty(String propertyName) { // NOTE: getProperty() will probably fail in applets, which // is why this is in a try block. String property = null; try { property = System.getProperty(propertyName); } catch (SecurityException security) { if (!propertyName.equals("ptolemy.ptII.dir")) { throw new RuntimeException("Could not find '" + propertyName + "' System property", security); } } if (propertyName.equals("user.dir")) { try { File userDirFile = new File(property); return userDirFile.getCanonicalPath(); } catch (IOException ex) { return property; } } if (property != null) { return property; } if (propertyName.equals("ptolemy.ptII.dirAsURL")) { // Return $PTII as a URL. For example, if $PTII was c:\ptII, // then return file:/c:/ptII/ File ptIIAsFile = new File(getProperty("ptolemy.ptII.dir")); try { URL ptIIAsURL = ptIIAsFile.toURI().toURL(); return ptIIAsURL.toString(); } catch (java.net.MalformedURLException malformed) { throw new RuntimeException("While trying to find '" + propertyName + "', could not convert '" + ptIIAsFile + "' to a URL", malformed); } } if (propertyName.equals("ptolemy.ptII.dir")) { String namedObjPath = "ptolemy/kernel/util/NamedObj.class"; String home = null; // PTII variable was not set URL namedObjURL = Thread.currentThread().getContextClassLoader().getResource(namedObjPath); if (namedObjURL != null) { String namedObjFileName = namedObjURL.getFile().toString(); // FIXME: How do we get from a URL to a pathname? if (namedObjFileName.startsWith("file:")) { // We get rid of either file:/ or file:\ namedObjFileName = namedObjFileName.substring(6); } String abnormalHome = namedObjFileName.substring(0, namedObjFileName.length() - namedObjPath.length()); // abnormalHome will have values like: "/C:/ptII/" // which cause no end of trouble, so we construct a File // and call toString(). home = (new File(abnormalHome)).toString(); // If we are running under Web Start, then strip off // the trailing "!" if (home.endsWith("!")) { home = home.substring(0, home.length() - 1); } // Web Start String ptsupportJarName = File.separator + "DMptolemy" + File.separator + "RMptsupport.jar"; if (home.endsWith(ptsupportJarName)) { home = home.substring(0, home.length() - ptsupportJarName.length()); } ptsupportJarName = File.separator + "ptolemy" + File.separator + "ptsupport.jar"; if (home.endsWith(ptsupportJarName)) { home = home.substring(0, home.length() - ptsupportJarName.length()); } } if (home == null) { throw new RuntimeException( "Could not find " + "'ptolemy.ptII.dir'" + " property. Also tried loading '" + namedObjPath + "' as a resource and working from that. " + "Vergil should be " + "invoked with -Dptolemy.ptII.dir" + "=\"$PTII\""); } try { System.setProperty("ptolemy.ptII.dir", home); } catch (SecurityException security) { // Ignore, we are probably running as an applet or -sandbox } return home; } if (property == null) { return ""; } return property; } }