OPENJPA-2632 use TCCL as fallback

openjpa-kernel/src/main/java/org/apache/openjpa/conf/OpenJPAConfiguration.java

@@ -219,6 +219,13 @@ public interface OpenJPAConfiguration
     public static final String OPTION_POSTLOAD_ON_MERGE =
         "openjpa.option.PostLoadOnMerge";
 
+    /**
+     * Option to enable TCCL if the result class for select new is not found
+     * in the entities classloader
+     */
+    public static final String OPTION_USE_TCCL_IN_SELECT_NEW =
+            "openjpa.option.UseTCCLinSelectNew";
+
     /**
      * Return the set of option strings supported by this runtime. This set
      * is mutable.
@@ -1949,5 +1956,32 @@ public interface OpenJPAConfiguration
       * @since 2.2.0
       */
       public void setOptimizeIdCopy(Boolean optimizeIds);
+
+      /**
+       * Indicates if the {@link Thread#contextClassLoader} should be used
+       * as fallback if the result class for {@code select new} is not found
+       * by the classloader of the entity.
+       *
+       * @since 2.4.2
+       */
+      public boolean getUseTCCLinSelectNew();
+
+      /**
+       * Indicates if the {@link Thread#contextClassLoader} should be used
+       * as fallback if the result class for {@code select new} is not found
+       * by the classloader of the entity.
+       *
+       * @since 2.4.2
+       */
+      public void setUseTCCLinSelectNew(boolean useTcclForSelectNew);
+
+      /**
+       * Indicates if the {@link Thread#contextClassLoader} should be used
+       * as fallback if the result class for {@code select new} is not found
+       * by the classloader of the entity.
+       *
+       * @since 2.4.2
+       */
+      public void setUseTCCLinSelectNew(Boolean useTcclForSelectNew);
 }
 

openjpa-kernel/src/main/java/org/apache/openjpa/conf/OpenJPAConfigurationImpl.java

@@ -177,6 +177,7 @@ public class OpenJPAConfigurationImpl
     public PluginListValue instrumentationProviders;
     public BooleanValue postLoadOnMerge;
     public BooleanValue optimizeIdCopy;
+    public BooleanValue useTcclForSelectNew;
 
     // custom values
     public BrokerFactoryValue brokerFactoryPlugin;
@@ -604,6 +605,10 @@ public OpenJPAConfigurationImpl(boolean derivations, boolean loadGlobals) {
         aliases = new String[] { "default", AuditLogger.class.getName(), };
         auditorPlugin.setAliases(aliases);
         auditorPlugin.setInstantiatingGetter("getAuditorInstance");
+
+        useTcclForSelectNew = addBoolean("UseTCCLinSelectNew");
+        useTcclForSelectNew.setDefault("false");
+        useTcclForSelectNew.set(false);
 
         // initialize supported options that some runtimes may not support
         supportedOptions.add(OPTION_NONTRANS_READ);
@@ -622,6 +627,7 @@ public OpenJPAConfigurationImpl(boolean derivations, boolean loadGlobals) {
         supportedOptions.add(OPTION_VALUE_INCREMENT);
         supportedOptions.add(OPTION_DATASTORE_CONNECTION);
         supportedOptions.add(OPTION_POSTLOAD_ON_MERGE);
+        supportedOptions.add(OPTION_USE_TCCL_IN_SELECT_NEW);
 
         if (derivations)
             ProductDerivations.beforeConfigurationLoad(this);
@@ -1873,5 +1879,22 @@ public void setOptimizeIdCopy(Boolean optimizeId) {
             setOptimizeIdCopy(optimizeId.booleanValue());
         }
     }
+
+    @Override
+    public boolean getUseTCCLinSelectNew() {
+        return useTcclForSelectNew.get();
+    }
+
+    @Override
+    public void setUseTCCLinSelectNew(boolean useTcclForSelectNew) {
+        this.useTcclForSelectNew.set(useTcclForSelectNew);
+    }
+
+    @Override
+    public void setUseTCCLinSelectNew(Boolean useTcclForSelectNew) {
+        if (useTcclForSelectNew != null) {
+            setUseTCCLinSelectNew(useTcclForSelectNew.booleanValue());
+        }
+    }
 }
 

openjpa-kernel/src/main/java/org/apache/openjpa/kernel/QueryImpl.java

@@ -1692,7 +1692,7 @@ else if (importName.endsWith(".*")) {
     private Class toClass(String name) {
         if (_loader == null)
             _loader = _broker.getConfiguration().getClassResolverInstance().
-                getClassLoader(_class, _broker.getClassLoader());
+                    getClassLoader(_class, _broker.getClassLoader());
         try {
             return Strings.toClass(name, _loader);
         } catch (RuntimeException re) {

openjpa-kernel/src/main/java/org/apache/openjpa/kernel/jpql/JPQLExpressionBuilder.java

@@ -22,6 +22,7 @@
 import java.io.Serializable;
 import java.lang.reflect.Field;
 import java.math.BigDecimal;
+import java.security.AccessController;
 import java.sql.Time;
 import java.sql.Timestamp;
 import java.util.ArrayList;
@@ -56,6 +57,7 @@
 import org.apache.openjpa.kernel.exps.Subquery;
 import org.apache.openjpa.kernel.exps.Value;
 import org.apache.openjpa.lib.log.Log;
+import org.apache.openjpa.lib.util.J2DoPrivHelper;
 import org.apache.openjpa.lib.util.Localizer;
 import org.apache.openjpa.lib.util.OrderedMap;
 import org.apache.openjpa.lib.util.Localizer.Message;
@@ -410,6 +412,22 @@ private void evalProjectionsResultShape(JPQLNode selectionsNode,
                     String baseName = left(node).getChild(n-1).text;
                     constructor = resolver.classForName(baseName, null);
                 }
+
+                if (constructor == null && resolver.getConfiguration().getUseTCCLinSelectNew()) {
+                    try {
+                        if (System.getSecurityManager() == null) {
+                            constructor = AccessController.doPrivileged(
+                                    J2DoPrivHelper.getForNameAction(resultClassName, false,
+                                        AccessController.doPrivileged(J2DoPrivHelper.getContextClassLoaderAction())));
+                        }
+                        else {
+                            constructor = Thread.currentThread().getContextClassLoader().loadClass(resultClassName);
+                        }
+                    } catch (Exception e) {
+                        // ignore
+                    }
+                }
+
                 if (constructor == null)
                     throw parseException(EX_USER, "no-constructor",
                             new Object[]{ resultClassName }, null);