scilab/modules/javasci/src/java/javasci/LibraryPath.java

   1 /*-----------------------------------------------------------------------------------*/\r
   2 /**\r
   3 * Modify java.library.path at runtime.\r
   4 * @author Allan CORNET - INRIA 2007\r
   5 */\r
   6 /*-----------------------------------------------------------------------------------*/\r
   7 package org.scilab.modules.jvm;\r
   8 /*-----------------------------------------------------------------------------------*/\r
   9 import java.io.IOException;\r
  10 import java.io.File;\r
  11 import java.lang.reflect.Field;\r
  12 /*-----------------------------------------------------------------------------------*/\r
  13 /*http://forum.java.sun.com/thread.jspa?threadID=135560&start=15&tstart=0 */\r
  14 /*-----------------------------------------------------------------------------------*/\r
  15 \r
  16 /**\r
  17  * LibraryPath to overload java.library.path.\r
  18  */\r
  19 public class LibraryPath {\r
  20 \r
  21         private static final String JAVALIBRARYPATH = "java.library.path";\r
  22         /**\r
  23          * Constructor\r
  24          */\r
  25         protected LibraryPath() {\r
  26                 /*  indicate that the requested operation is not supported */\r
  27                 throw new UnsupportedOperationException();              \r
  28         }\r
  29 /*--------------------------------------------------------------------------*/  \r
  30         /**\r
  31          * checks if pathToAdd already exists\r
  32      * @param currentpaths list of current paths\r
  33      * @param pathToAdd path to add\r
  34      * @return a boolean true if path already exists\r
  35      */\r
  36         private static boolean pathAlreadyExists(String currentpaths, String pathToAdd) {\r
  37     String[] paths = currentpaths.split("" + File.pathSeparatorChar);\r
  38         for (String libraryPath : paths) {\r
  39             if (libraryPath.equalsIgnoreCase(pathToAdd)) { return true; }\r
  40         }\r
  41         return false;\r
  42     }\r
  43 /*--------------------------------------------------------------------------*/\r
  44         /**\r
  45          * add a path to java.library.path \r
  46          * @param p path to add\r
  47          * @throws IOException return a exception\r
  48          */\r
  49         public static void addPath(final String p) throws IOException {\r
  50         if (!pathAlreadyExists(System.getProperty(JAVALIBRARYPATH), p)) {\r
  51                 String newLibPath = p + File.pathSeparator + System.getProperty(JAVALIBRARYPATH);\r
  52                 System.setProperty(JAVALIBRARYPATH, newLibPath);\r
  53                 try {\r
  54                         Field fieldSysPath = ClassLoader.class.getDeclaredField("sys_paths");\r
  55                         fieldSysPath.setAccessible(true);\r
  56                         if (fieldSysPath != null) {\r
  57                 fieldSysPath.set(System.class.getClassLoader(), null);\r
  58                 }\r
  59             } catch (NoSuchFieldException e) {\r
  60                 throw new IOException("Error NoSuchFieldException, could not add path to " + JAVALIBRARYPATH);\r
  61             } catch (IllegalAccessException e) {\r
  62                 throw new IOException("Error IllegalAccessException, could not add path to " + JAVALIBRARYPATH);\r
  63             }\r
  64                 }\r
  65   }\r
  66  \r
  67 /*--------------------------------------------------------------------------*/\r
  68 /**\r
  69  * get the scilab java.library.path.\r
  70  * @return librarypath\r
  71  */\r
  72         public static String[] getLibraryPath() {\r
  73                 String librarypath = System.getProperty(JAVALIBRARYPATH);\r
  74                 String[] paths = librarypath.split("" + File.pathSeparatorChar);\r
  75                 return paths;\r
  76         }\r
  77 }\r
  78 /*-----------------------------------------------------------------------------------*/\r