Fix #57 (NPE for @JsonAppend)

Author: cowtowncoder

release-notes/VERSION

@@ -8,6 +8,8 @@ Project: jackson-module-afterburner
 
 #56: Afterburner does not respect DeserializationFeature.UNWRAP_SINGLE_VALUE_ARRAYS
  (reported by shollander@github)
+#57: `@JsonAppend` causes `NullPointerException`
+ (reported by cleiner@github)
 
 2.6.1 (09-Aug-2015)
 

src/main/java/com/fasterxml/jackson/module/afterburner/ser/SerializerModifier.java

@@ -1,5 +1,6 @@
 package com.fasterxml.jackson.module.afterburner.ser;
 
+import java.lang.reflect.Member;
 import java.lang.reflect.Modifier;
 import java.util.*;
 
@@ -8,7 +9,6 @@
 import com.fasterxml.jackson.databind.introspect.AnnotatedMethod;
 import com.fasterxml.jackson.databind.ser.*;
 import com.fasterxml.jackson.databind.util.ClassUtil;
-
 import com.fasterxml.jackson.module.afterburner.util.MyClassLoader;
 
 public class SerializerModifier extends BeanSerializerModifier
@@ -78,8 +78,13 @@ protected PropertyAccessorCollector findProperties(Class<?> beanClass,
             Class<?> type = bpw.getPropertyType();
             AnnotatedMember member = bpw.getMember();
 
-            // First: we can't access private fields or methods....
-            if (Modifier.isPrivate(member.getMember().getModifiers())) {
+            Member jdkMember = member.getMember();
+            // 11-Sep-2015, tatu: Let's skip virtual members (related to #57)
+            if (jdkMember == null) {
+                continue;
+            }
+            // We can't access private fields or methods, skip:
+            if (Modifier.isPrivate(jdkMember.getModifiers())) {
                 continue;
             }
             // (although, interestingly enough, can seem to access private classes...)

src/test/java/com/fasterxml/jackson/module/afterburner/ser/JsonAppendTest.java

@@ -0,0 +1,49 @@
+package com.fasterxml.jackson.module.afterburner.ser;
+
+import com.fasterxml.jackson.core.JsonGenerator;
+import com.fasterxml.jackson.databind.*;
+import com.fasterxml.jackson.databind.annotation.JsonAppend;
+import com.fasterxml.jackson.databind.cfg.MapperConfig;
+import com.fasterxml.jackson.databind.introspect.AnnotatedClass;
+import com.fasterxml.jackson.databind.introspect.BeanPropertyDefinition;
+import com.fasterxml.jackson.databind.ser.VirtualBeanPropertyWriter;
+import com.fasterxml.jackson.databind.util.Annotations;
+import com.fasterxml.jackson.module.afterburner.AfterburnerTestBase;
+
+// most for [module-afterburner#57]
+public class JsonAppendTest extends AfterburnerTestBase
+{
+    @JsonAppend(props = @JsonAppend.Prop(name = "virtual", value = MyVirtualPropertyWriter.class))
+    public static class Pojo {
+        public final String name;
+        public Pojo(String name) {
+            this.name = name;
+        }
+    }
+
+    public static class MyVirtualPropertyWriter extends VirtualBeanPropertyWriter {
+        protected MyVirtualPropertyWriter() { }
+
+        protected MyVirtualPropertyWriter(BeanPropertyDefinition propDef, Annotations contextAnnotations,
+                JavaType declaredType) {
+            super(propDef, contextAnnotations, declaredType);
+        }
+        @Override
+        protected Object value(Object bean, JsonGenerator g, SerializerProvider prov) throws Exception {
+            return "bar";
+        }
+        @Override
+        public VirtualBeanPropertyWriter withConfig(MapperConfig<?> config, AnnotatedClass declaringClass,
+                BeanPropertyDefinition propDef, JavaType type) {
+            return new MyVirtualPropertyWriter(propDef, declaringClass.getAnnotations(), type);
+        }
+    }
+
+    public void testSimpleAppend() throws Exception
+    {
+        ObjectMapper mapper = mapperWithModule();
+//        ObjectMapper mapper = new ObjectMapper();
+        String json = mapper.writeValueAsString(new Pojo("foo"));
+        assertEquals("{\"name\":\"foo\",\"virtual\":\"bar\"}", json);
+    }
+}