src/share/classes/sun/misc/ClassFileTransformer.java

@@ -23,62 +23,48 @@
  * questions.
  */
 package sun.misc;
 
 import java.util.ArrayList;
+import java.util.List;
 
 /**
- * This is an abstract base class which is called by java.lang.ClassLoader
- * when ClassFormatError is thrown inside defineClass().
- *
- * The purpose of this class is to allow applications (e.g. Java Plug-in)
- * to have a chance to transform the byte code from one form to another
- * if necessary.
- *
- * One application of this class is used by Java Plug-in to transform
- * malformed JDK 1.1 class file into a well-formed Java 2 class file
- * on-the-fly, so JDK 1.1 applets with malformed class file in the
- * Internet may run in Java 2 after transformation.
+ * This is an abstract base class originally intended to be called by
+ * {@code java.lang.ClassLoader} when {@code ClassFormatError} is
+ * thrown inside {@code defineClass()}. It is no longer hooked into
+ * {@code ClassLoader} and will be removed in a future release.
  *
  * @author      Stanley Man-Kit Ho
  */
 
-public abstract class ClassFileTransformer
-{
-    // Singleton of ClassFileTransformer
-    //
-    private static ArrayList<ClassFileTransformer> transformerList
+@Deprecated
+public abstract class ClassFileTransformer {
+
+    private static final List<ClassFileTransformer> transformers
         = new ArrayList<ClassFileTransformer>();
-    private static ClassFileTransformer[] transformers
-        = new ClassFileTransformer[0];
 
     /**
      * Add the class file transformer object.
      *
      * @param t Class file transformer instance
      */
-    public static void add(ClassFileTransformer t)
-    {
-        synchronized(transformerList)
-        {
-            transformerList.add(t);
-            transformers = transformerList.toArray(new ClassFileTransformer[0]);
+    public static void add(ClassFileTransformer t) {
+        synchronized (transformers) {
+            transformers.add(t);
         }
     }
 
     /**
      * Get the array of ClassFileTransformer object.
      *
      * @return ClassFileTransformer object array
      */
-    public static ClassFileTransformer[] getTransformers()
-    {
-        // transformers is not intended to be changed frequently,
-        // so it is okay to not put synchronized block here
-        // to speed up performance.
-        //
-        return transformers;
+    public static ClassFileTransformer[] getTransformers() {
+        synchronized (transformers) {
+            ClassFileTransformer[] result = new ClassFileTransformer[transformers.size()];
+            return transformers.toArray(result);
+        }
     }
 
 
     /**
      * Transform a byte array from one to the other.