[DROOLS-209] NoSuchMethodException when traiting a legacy class witho…

…ut a default constructor
apache · Jul 31, 2013 · 0e2f33f · 0e2f33f
1 parent c950014
commit 0e2f33f
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Showing 2 changed files with 70 additions and 2 deletions.
diff --git a/drools-compiler/src/test/java/org/drools/factmodel/traits/TraitTest.java b/drools-compiler/src/test/java/org/drools/factmodel/traits/TraitTest.java
@@ -4407,4 +4407,55 @@ public void traitLogicalRemovalSimple( ) {
     }
 
 
+
+    public static class TraitableFoo {
+
+        public TraitableFoo( String id, int x, Object k ) {
+
+        }
+
+    }
+
+    public static class XYZ extends TraitableFoo {
+
+        public XYZ() {
+            super( null, 0, null );
+        }
+
+    }
+
+
+    @Test
+    public void traitDonLegacyClassWithoutEmptyConstructor( ) {
+        String drl = "package org.drools.compiler.trait.test;\n" +
+                     "\n" +
+                     "import org.drools.factmodel.traits.TraitTest.TraitableFoo;\n" +
+                     "import org.drools.factmodel.traits.Traitable;\n" +
+                     "\n" +
+                     "\n" +
+                     "declare trait Bar\n" +
+                     "end\n" +
+                     "\n" +
+                     "rule \"Don\"\n" +
+                     "when\n" +
+                     " $f : TraitableFoo( )\n" +
+                     "then\n" +
+                     " Bar b = don( $f, Bar.class );\n" +
+                     "end";
+
+
+        StatefulKnowledgeSession ksession = getSessionFromString(drl);
+        TraitFactory.setMode( TraitFactory.VirtualPropertyMode.MAP, ksession.getKnowledgeBase() );
+
+        ksession.insert( new TraitableFoo( "xx", 0, null ) );
+        ksession.fireAllRules();
+
+        for ( Object o : ksession.getObjects() ) {
+            System.out.println( o );
+        }
+
+    }
+
+
+
 }
diff --git a/drools-core/src/main/java/org/drools/factmodel/traits/TraitCoreWrapperClassBuilderImpl.java b/drools-core/src/main/java/org/drools/factmodel/traits/TraitCoreWrapperClassBuilderImpl.java
@@ -25,6 +25,7 @@
 import java.io.IOException;
 import java.io.ObjectInput;
 import java.io.ObjectOutput;
+import java.lang.reflect.Constructor;
 import java.lang.reflect.InvocationTargetException;
 import java.lang.reflect.Method;
 import java.lang.reflect.Modifier;
@@ -84,8 +85,24 @@ public byte[] buildClass( ClassDefinition core ) throws IOException,
             mv = cw.visitMethod( ACC_PUBLIC, "<init>", "()V", null, null );
             mv.visitCode();
 
-            mv.visitVarInsn( ALOAD, 0 );
-            mv.visitMethodInsn( INVOKESPECIAL, BuildUtils.getInternalType( coreName ), "<init>", "()V" );
+            try {
+                coreKlazz.getConstructor();
+                mv.visitVarInsn( ALOAD, 0 );
+                mv.visitMethodInsn( INVOKESPECIAL, BuildUtils.getInternalType( coreName ), "<init>", "()V" );
+            } catch ( NoSuchMethodException nsme ) {
+                Constructor con = coreKlazz.getConstructors()[ 0 ];
+                Class[] params = con.getParameterTypes();
+
+                mv.visitVarInsn( ALOAD, 0 );
+                for ( Class param : params ) {
+                    mv.visitInsn( BuildUtils.zero( param.getName() ) );
+                }
+                mv.visitMethodInsn( INVOKESPECIAL,
+                                    BuildUtils.getInternalType( coreName ),
+                                    "<init>",
+                                    Type.getConstructorDescriptor( con ) );
+            }
+
 
 //            mv.visitVarInsn( ALOAD, 0 );
 //            mv.visitTypeInsn( NEW, Type.getInternalName( HashMap.class ) );