98 
  99     // the URL class path or null if there is no class path
 100     private final URLClassPath ucp;
 101 
 102 
 103     /**
 104      * A module defined/loaded by a built-in class loader.
 105      *
 106      * A LoadedModule encapsulates a ModuleReference along with its CodeSource
 107      * URL to avoid needing to create this URL when define classes.
 108      */
 109     private static class LoadedModule {
 110         private final BuiltinClassLoader loader;
 111         private final ModuleReference mref;
 112         private final URL codeSourceURL;          // may be null
 113 
 114         LoadedModule(BuiltinClassLoader loader, ModuleReference mref) {
 115             URL url = null;
 116             if (mref.location().isPresent()) {
 117                 try {
 118                     url = mref.location().get().toURL();
 119                 } catch (MalformedURLException e) { }
 120             }
 121             this.loader = loader;
 122             this.mref = mref;
 123             this.codeSourceURL = url;
 124         }
 125 
 126         BuiltinClassLoader loader() { return loader; }
 127         ModuleReference mref() { return mref; }
 128         String name() { return mref.descriptor().name(); }
 129         URL codeSourceURL() { return codeSourceURL; }
 130     }
 131 
 132 
 133     // maps package name to loaded module for modules in the boot layer
 134     private static final Map<String, LoadedModule> packageToModule
 135         = new ConcurrentHashMap<>(1024);
 136 
 137     // maps a module name to a module reference
 138     private final Map<String, ModuleReference> nameToModule;

  98 
  99     // the URL class path or null if there is no class path
 100     private final URLClassPath ucp;
 101 
 102 
 103     /**
 104      * A module defined/loaded by a built-in class loader.
 105      *
 106      * A LoadedModule encapsulates a ModuleReference along with its CodeSource
 107      * URL to avoid needing to create this URL when define classes.
 108      */
 109     private static class LoadedModule {
 110         private final BuiltinClassLoader loader;
 111         private final ModuleReference mref;
 112         private final URL codeSourceURL;          // may be null
 113 
 114         LoadedModule(BuiltinClassLoader loader, ModuleReference mref) {
 115             URL url = null;
 116             if (mref.location().isPresent()) {
 117                 try {
 118                     url = mref.location().getWhenPresent().toURL();
 119                 } catch (MalformedURLException e) { }
 120             }
 121             this.loader = loader;
 122             this.mref = mref;
 123             this.codeSourceURL = url;
 124         }
 125 
 126         BuiltinClassLoader loader() { return loader; }
 127         ModuleReference mref() { return mref; }
 128         String name() { return mref.descriptor().name(); }
 129         URL codeSourceURL() { return codeSourceURL; }
 130     }
 131 
 132 
 133     // maps package name to loaded module for modules in the boot layer
 134     private static final Map<String, LoadedModule> packageToModule
 135         = new ConcurrentHashMap<>(1024);
 136 
 137     // maps a module name to a module reference
 138     private final Map<String, ModuleReference> nameToModule;