src/java.base/share/classes/jdk/internal/loader/ClassLoaders.java

@@ -34,10 +34,11 @@
 import java.util.jar.Manifest;
 
 import jdk.internal.access.JavaLangAccess;
 import jdk.internal.access.SharedSecrets;
 import jdk.internal.misc.VM;
+import jdk.internal.vm.annotation.Stable;
 
 /**
  * Creates and provides access to the built-in platform and application class
  * loaders. It also creates the class loader that is used to locate resources
  * in modules defined to the boot class loader.

@@ -52,20 +53,49 @@
     // the built-in class loaders
     private static final BootClassLoader BOOT_LOADER;
     private static final PlatformClassLoader PLATFORM_LOADER;
     private static final AppClassLoader APP_LOADER;
 
+    static class ArchivedData {
+        private final BootClassLoader boot_loader;
+        private final PlatformClassLoader platform_loader;
+        private final AppClassLoader app_loader;
+
+        private ArchivedData() {
+            boot_loader = BOOT_LOADER;
+            platform_loader = PLATFORM_LOADER;
+            app_loader = APP_LOADER;
+        }
+
+        static void archive() {
+            singleton = new ArchivedData();
+        }
+
+        static ArchivedData get() {
+            return singleton;
+        }
+
+        private static ArchivedData singleton;
+    }
+
     // Creates the built-in class loaders.
     static {
+        VM.initializeFromArchive(ArchivedData.class);
+        ArchivedData archivedData = ArchivedData.get();
+        if (archivedData != null) {
+            // assert VM.getSavedProperty("jdk.boot.class.path.append") == null
+            BOOT_LOADER = archivedData.boot_loader;
+            PLATFORM_LOADER = archivedData.platform_loader;
+        } else {
         // -Xbootclasspath/a or -javaagent with Boot-Class-Path attribute
         String append = VM.getSavedProperty("jdk.boot.class.path.append");
         BOOT_LOADER =
             new BootClassLoader((append != null && !append.isEmpty())
                 ? new URLClassPath(append, true)
                 : null);
         PLATFORM_LOADER = new PlatformClassLoader(BOOT_LOADER);
-
+        }
         // A class path is required when no initial module is specified.
         // In this case the class path defaults to "", meaning the current
         // working directory.  When an initial module is specified, on the
         // contrary, we drop this historic interpretation of the empty
         // string and instead treat it as unspecified.

@@ -73,11 +103,17 @@
         if (cp == null || cp.isEmpty()) {
             String initialModuleName = System.getProperty("jdk.module.main");
             cp = (initialModuleName == null) ? "" : null;
         }
         URLClassPath ucp = new URLClassPath(cp, false);
+        if (archivedData != null) {
+            APP_LOADER = archivedData.app_loader;
+            APP_LOADER.setClassPath(ucp);
+        } else {
         APP_LOADER = new AppClassLoader(PLATFORM_LOADER, ucp);
+            ArchivedData.archive();
+        }
     }
 
     /**
      * Returns the class loader that is used to find resources in modules
      * defined to the boot class loader.

@@ -142,11 +178,15 @@
         static {
             if (!ClassLoader.registerAsParallelCapable())
                 throw new InternalError();
         }
 
-        final URLClassPath ucp;
+        @Stable URLClassPath ucp;
+        void setClassPath(URLClassPath ucp) {
+            super.setClassPath(ucp);
+            this.ucp = ucp;
+        }
 
         AppClassLoader(PlatformClassLoader parent, URLClassPath ucp) {
             super("app", parent, ucp);
             this.ucp = ucp;
         }

@@ -188,10 +228,15 @@
          * Called by the VM to support define package for AppCDS
          */
         protected Package defineOrCheckPackage(String pn, Manifest man, URL url) {
             return super.defineOrCheckPackage(pn, man, url);
         }
+
+        // Called from VM only, during -Xshare:dump
+        private void resetArchivedStates() {
+            ucp = null;
+        }
     }
 
     /**
      * Attempts to convert the given string to a file URL.
      *