scilab/modules/javasci/src/java/javasci/ClassPath.java

   1 /*--------------------------------------------------------------------------*/
   2 /*
   3  * Scilab ( http://www.scilab.org/ ) - This file is part of Scilab
   4  * Copyright (C) INRIA - Allan CORNET
   5  * Copyright (C) 2008 - INRIA - Sylvestre LEDRU
   6  *
   7  * This file must be used under the terms of the CeCILL.
   8  * This source file is licensed as described in the file COPYING, which
   9  * you should have received as part of this distribution.  The terms
  10  * are also available at
  11  * http://www.cecill.info/licences/Licence_CeCILL_V2-en.txt
  12  *
  13  */
  14
  15 /*--------------------------------------------------------------------------*/
  16 package javasci;
  17 /*--------------------------------------------------------------------------*/
  18 import java.lang.reflect.Method;
  19 import java.lang.reflect.InvocationTargetException;
  20 import java.io.File;
  21 import java.io.IOException;
  22 import java.net.URL;
  23 import java.net.URLClassLoader;
  24 import java.net.URI;
  25 import java.util.Iterator;
  26 import java.util.Vector;
  27 /*--------------------------------------------------------------------------*/
  28 /**
  29  * ClassPath to overload java classpath.
  30  */
  31 public class ClassPath {
  32
  33         private static final Class[] parameters = new Class[]{URL.class};
  34
  35         private static Vector<URL> queued = new Vector<URL>();
  36
  37         /**
  38          * add a filename to java classpath.
  39          * @param s a filename
  40          * @throws IOException if an error occurs
  41          */
  42         public static void addFile(final String s,int i) throws IOException {
  43                 addFile(new File(s), i);
  44         }
  45         /*-----------------------------------------------------------------------*/
  46         /**
  47          * add a file to java classpath.
  48          * @param  f a file
  49          * @throws IOException if an error occurs
  50          */
  51         public static void addFile(final File f, int i) throws IOException {
  52                 addURL(f.toURI().toURL(), i);
  53         }
  54
  55         /*-----------------------------------------------------------------------*/
  56         /**
  57          * Add a URL to classpath.
  58          * @param u URL of the classes (jar or path)
  59          * @param i the type of load: i=0 startup / i=1 background / i=2 onUse
  60          */
  61         public static void addURL(final URL u, int i) {
  62
  63                 final URLClassLoader sysloader = (URLClassLoader) ClassLoader.getSystemClassLoader();
  64                 Class sysclass = URLClassLoader.class;
  65
  66                 try {
  67
  68                         final Method method = sysclass.getDeclaredMethod("addURL", parameters);
  69                         method.setAccessible(true);
  70                         switch (i) {
  71                                 case 0: /* Load now */
  72                                         method.invoke(sysloader , new Object[] { u });
  73                                         break;
  74                                 case 1: /* Load later (background) */
  75                                         queued.add(u);
  76                                         break;
  77                         }
  78
  79                 } catch (NoSuchMethodException e) {
  80                         System.err.println("Error: Cannot find the declared method: " + e.getLocalizedMessage());
  81                 } catch (IllegalAccessException e) {
  82                         System.err.println("Error: Illegal access: " + e.getLocalizedMessage());
  83                 } catch (InvocationTargetException e) {
  84                         System.err.println("Error: Could not invocate target: " + e.getLocalizedMessage());
  85                 }
  86
  87         }
  88         /*-----------------------------------------------------------------------*/
  89         /**
  90          * Get the classpath loaded
  91          * @return classpath The list of the classpath
  92          */
  93         public static String[] getClassPath() {
  94
  95                 URLClassLoader sysloader = (URLClassLoader) ClassLoader.getSystemClassLoader();
  96                 URL[] path = sysloader.getURLs();
  97                 String[] paths = new String[path.length];
  98                 for (int i = 0; i < path.length; i++) {
  99                         paths[i] = path[i].getFile();
 100                 }
 101                 return paths;
 102         }
 103
 104
 105     /**
 106      * Load all the classpath in dedicated threads in background
 107      */
 108         public static void loadBackGroundClassPath(){
 109                 Thread backgroundLoader = new Thread() {
 110                                 public void run() {
 111                                         try {
 112
 113                                                 Iterator<URL> urlIt = queued.iterator();
 114
 115                                                 while (urlIt.hasNext()) {
 116                                                         ClassPath.addURL(urlIt.next(),0);
 117                                                 }
 118
 119                                         }catch (Exception e){
 120                                                 System.err.println("Error : "+e.getLocalizedMessage());
 121                                         }
 122                                 }
 123                         };
 124                 backgroundLoader.start();
 125         }
 126 }
 127 /*--------------------------------------------------------------------------*/
 128