WELD-2744 Change how we create ClassFile instances to avoid instantia…

…ting DefaultClassFactory.INSTANCE

impl/src/main/java/org/jboss/weld/bean/proxy/DummyClassFactoryImpl.java

@@ -0,0 +1,28 @@
+package org.jboss.weld.bean.proxy;
+
+import org.jboss.classfilewriter.ClassFactory;
+import org.jboss.weld.bean.proxy.util.WeldDefaultProxyServices;
+
+import java.security.ProtectionDomain;
+
+/**
+ * A dummy implementation which has only one purpose - to avoid instantiating {@code DefaultClassFactory.INSTANCE}.
+ * The sole method in this class is never used as we define classes using different means that further vary
+ * between in-container (such as WildFly) and SE setups.
+ * <p>
+ * See {@link WeldDefaultProxyServices#defineClass(Class, String, byte[], int, int)} for details on how we define
+ * classes.
+ */
+class DummyClassFactoryImpl implements ClassFactory {
+
+    private DummyClassFactoryImpl() {
+    }
+
+    // final so that there's only one instance that's being referenced from anywhere
+    static final DummyClassFactoryImpl INSTANCE = new DummyClassFactoryImpl();
+
+    @Override
+    public Class<?> defineClass(ClassLoader loader, String name, byte[] b, int off, int len, ProtectionDomain protectionDomain) throws ClassFormatError {
+        throw new UnsupportedOperationException("DummyClasFactoryImpl should not be used to define classes");
+    }
+}

impl/src/main/java/org/jboss/weld/bean/proxy/ProxyFactory.java

@@ -499,7 +499,10 @@ private Class<T> createProxyClass(Class<?> originalClass, String proxyClassName)
 
     private ClassFile newClassFile(String name, int accessFlags, String superclass, String... interfaces) {
         try {
-            return new ClassFile(name, accessFlags, superclass, interfaces);
+            // We need to use a (non-deprecated) method that avoids instantiating DefaultClassFactory.INSTANCE
+            // If that happens, we will have module accessibility issues and the need to use --add-opens clausules
+            // NOTE: the CL and ClassFactory are never really used to define the class, see WeldDefaultProxyServices
+            return new ClassFile(name, accessFlags, superclass, ProxyFactory.class.getClassLoader(), DummyClassFactoryImpl.INSTANCE, interfaces);
         } catch (Exception e) {
             throw BeanLogger.LOG.unableToCreateClassFile(name, e.getCause());
         }

impl/src/main/java/org/jboss/weld/bean/proxy/util/WeldDefaultProxyServices.java

@@ -46,7 +46,7 @@ public Class<?> defineClass(Class<?> originalClass, String className, byte[] cla
         ClassLoader originalLoader = originalClass.getClassLoader();
         if (originalLoader == null) {
             originalLoader = Thread.currentThread().getContextClassLoader();
-            // is it's still null we cannot solve this issue and we need to throw an exception
+            // if it's still null we cannot solve this issue, and we need to throw an exception
             if (originalLoader == null) {
                 throw BeanLogger.LOG.cannotDetermineClassLoader(className, originalClass);
             }