(WIP) Reflection testing wrt #4907

src/main/java/com/fasterxml/jackson/databind/introspect/AnnotatedClass.java

@@ -86,6 +86,15 @@ public final class AnnotatedClass
      */
     protected final boolean _collectAnnotations;
 
+    /**
+     * Flag that indicates whether member (Field, Method, Constructor}
+     * detection should occur: starting with 2.19 is disabled for <b>core</b> JDK
+     * types {@link ClassUtil#isJDKCoreClass(Class)}).
+     *
+     * @since 2.20
+     */
+    protected final boolean _collectMembers;
+
     /*
     /**********************************************************
     /* Gathered information
@@ -152,6 +161,19 @@ public final class AnnotatedClass
         _mixInResolver = mir;
         _typeFactory = tf;
         _collectAnnotations = collectAnnotations;
+        // But need to collect for some JDK types:
+        //
+        // - Throwables
+        _collectMembers = (type != null)
+                && (!ClassUtil.isJDKCoreClass(rawType)
+                || type.hasRawClass(Optional.class)
+                || type.hasRawClass(StackTraceElement.class)
+                || Throwable.class.isAssignableFrom(rawType)
+                || type.hasRawClass(Thread.class)
+                || type.hasRawClass(ThreadGroup.class)
+                );
+
+System.out.println(" AnnotatedClass("+_type+"), coll anno? "+collectAnnotations+" coll mem? "+_collectMembers);
     }
 
     /**
@@ -171,6 +193,7 @@ public final class AnnotatedClass
         _mixInResolver = null;
         _typeFactory = null;
         _collectAnnotations = false;
+        _collectMembers = false;
     }
 
     /**
@@ -327,9 +350,12 @@ private final List<AnnotatedField> _fields() {
         List<AnnotatedField> f = _fields;
         if (f == null) {
             // 09-Jun-2017, tatu: _type only null for primordial, placeholder array types.
-            if (_type == null) {
+            // 26-Apr-2025, tatu: [databind#4907] Less introspection, skip for core JDK types
+            if (_type == null || !_collectMembers) {
+System.out.println("SKIP Collecting _fields() for "+_type);
                 f = Collections.emptyList();
             } else {
+System.out.println("Collecting _fields() for "+_type);
                 f = AnnotatedFieldCollector.collectFields(_annotationIntrospector,
                         this, _mixInResolver, _typeFactory, _type, _collectAnnotations);
             }
@@ -343,9 +369,11 @@ private final AnnotatedMethodMap _methods() {
         if (m == null) {
             // 09-Jun-2017, tatu: _type only null for primordial, placeholder array types.
             //    NOTE: would be great to have light-weight shareable maps; no such impl exists for now
-            if (_type == null) {
+            if (_type == null) { // || !_collectMembers) {
+System.out.println("SKIP Collecting _methods() for: "+_type);
                 m = new AnnotatedMethodMap();
             } else {
+System.out.println("Collecting _methods() for "+_type);
                 m = AnnotatedMethodCollector.collectMethods(_annotationIntrospector,
                         this,
                         _mixInResolver, _typeFactory,
@@ -359,9 +387,12 @@ private final AnnotatedMethodMap _methods() {
     private final Creators _creators() {
         Creators c = _creators;
         if (c == null) {
-            if (_type == null) {
+            // 26-Apr-2025, tatu: [databind#4907] Less introspection, skip for core JDK types
+            if (_type == null || !_collectMembers) {
+System.out.println("SKIP Collecting _creators() for: "+_type);
                 c = NO_CREATORS;
             } else {
+System.out.println("Collecting _creators() for "+_type);
                 c = AnnotatedCreatorCollector.collectCreators(_annotationIntrospector,
                         _typeFactory,
                         this, _type, _primaryMixIn, _collectAnnotations);

src/main/java/com/fasterxml/jackson/databind/introspect/AnnotatedClassResolver.java

@@ -132,6 +132,8 @@ static AnnotatedClass createArrayType(MapperConfig<?> config, Class<?> raw) {
     }
 
     AnnotatedClass resolveFully() {
+System.out.println(" AnnotatedClassResolver.resolveFully() for "+_type);
+
         List<JavaType> superTypes = new ArrayList<>(8);
         if (!_type.hasRawClass(Object.class)) {
             if (_type.isInterface()) {

src/main/java/com/fasterxml/jackson/databind/introspect/BasicClassIntrospector.java

@@ -83,6 +83,7 @@ public BasicBeanDescription forSerialization(SerializationConfig config,
             // structured types as well
             desc = _findStdJdkCollectionDesc(config, type);
             if (desc == null) {
+System.out.println("BasicBeanDescription.forSerialization() for "+type);
                 desc = BasicBeanDescription.forSerialization(collectProperties(config,
                         type, r, true));
             }
@@ -101,6 +102,7 @@ public BasicBeanDescription forDeserialization(DeserializationConfig config,
             // structured types as well
             desc = _findStdJdkCollectionDesc(config, type);
             if (desc == null) {
+System.out.println("BasicBeanDescription.forDeserialization() for "+type);
                 desc = BasicBeanDescription.forDeserialization(collectProperties(config,
                         type, r, false));
             }
@@ -127,6 +129,7 @@ public BasicBeanDescription forCreation(DeserializationConfig config,
             // structured types as well
             desc = _findStdJdkCollectionDesc(config, type);
             if (desc == null) {
+System.out.println("BasicBeanDescription.forCreation() for "+type);
                 desc = BasicBeanDescription.forDeserialization(
                         collectProperties(config, type, r, false));
             }
@@ -170,6 +173,7 @@ public BasicBeanDescription forDirectClassAnnotations(MapperConfig<?> config,
     protected POJOPropertiesCollector collectProperties(MapperConfig<?> config,
             JavaType type, MixInResolver r, boolean forSerialization)
     {
+System.out.println("  collectProperties() for "+type);
         final AnnotatedClass classDef = _resolveAnnotatedClass(config, type, r);
         final AccessorNamingStrategy accNaming = type.isRecordType()
                 ? config.getAccessorNaming().forRecord(config, classDef)

src/test/java/com/fasterxml/jackson/databind/misc/Reflection4907Test.java

@@ -0,0 +1,58 @@
+package com.fasterxml.jackson.databind.misc;
+
+import org.junit.jupiter.api.Test;
+
+import com.fasterxml.jackson.databind.*;
+import com.fasterxml.jackson.databind.testutil.DatabindTestUtil;
+
+import static org.junit.jupiter.api.Assertions.assertNotNull;
+
+public class Reflection4907Test extends DatabindTestUtil
+{
+    static class SqlDatePojo {
+        public String name;
+        public java.sql.Date date;
+
+        public SqlDatePojo() {
+        }
+
+        public SqlDatePojo(String name, java.sql.Date date) {
+            this.name = name;
+            this.date = date;
+        }
+
+        public SqlDatePojo(java.sql.Date date) {
+            this.date = date;
+        }
+
+        public java.sql.Date getDate() {
+            return date;
+        }
+
+        public void setDate(java.sql.Date date) {
+            this.date = date;
+        }
+    }
+
+    private final ObjectMapper MAPPER = newJsonMapper();
+
+    // [databind#4907]
+    @Test
+    public void test4907Read() throws Exception {
+System.err.println("<testRead>");
+        SqlDatePojo pojo = MAPPER.readValue(a2q("{'date':'2000-01-01', 'name':'foo'}"),
+                SqlDatePojo.class);
+System.err.println("</testRead>");
+        assertNotNull(pojo);
+    }
+
+    // [databind#4907]
+    @Test
+    public void test4907Write() throws Exception {
+System.err.println("<testWrite>");
+         String json = MAPPER.writeValueAsString(new SqlDatePojo("foobar",
+                 java.sql.Date.valueOf("2000-01-01")));
+ System.err.println("</testWrite>");
+         assertNotNull(json);
+    }
+}

src/test/java/com/fasterxml/jackson/databind/ser/jdk/JDKTypeSerializationTest.java

@@ -241,8 +241,8 @@ public void testNonStandardProperties() throws Exception
     public void testThreadSerialization() throws Exception
     {
         final Thread input = Thread.currentThread();
-//        String json = MAPPER.writerWithDefaultPrettyPrinter()
-//                .writeValueAsString(input);
+//      System.err.println("Thread -> "+MAPPER.writerWithDefaultPrettyPrinter().writeValueAsString(input));
+
         Map<?,?> asMap = MAPPER.convertValue(input, Map.class);
 //        System.err.println("PROPS -> "+asMap.keySet());