Skipping over groovy metadata class + groovy test. (FasterXML#118)

jr-objects/pom.xml

@@ -40,6 +40,12 @@ has no other dependencies, and provides additional builder-style content generat
       <artifactId>jackson-core</artifactId>
       <version>${jackson.version.core}</version>
     </dependency>
+    <dependency>
+      <groupId>org.apache.groovy</groupId>
+      <artifactId>groovy</artifactId>
+      <version>4.0.18</version>
+      <scope>test</scope>
+    </dependency>
   </dependencies>
 
   <build>
@@ -54,6 +60,21 @@ has no other dependencies, and provides additional builder-style content generat
         </configuration>
 
       </plugin>
+
+      <!-- 20-Feb-2024, tatu: Need Groovy compilation for one test
+	-->
+      <plugin>
+        <groupId>org.codehaus.gmaven</groupId>
+        <artifactId>gmaven-plugin</artifactId>
+        <version>1.5</version>
+        <executions>
+          <execution>
+           <goals>
+             <goal>testCompile</goal>
+           </goals>
+          </execution>
+        </executions>
+      </plugin>
       <plugin>
         <groupId>com.google.code.maven-replacer-plugin</groupId>
         <artifactId>replacer</artifactId>

jr-objects/src/main/java/com/fasterxml/jackson/jr/ob/impl/BeanPropertyIntrospector.java

@@ -116,8 +116,7 @@ private static void _introspect(Class<?> currType, Map<String, PropBuilder> prop
             final int flags = m.getModifiers();
             // 13-Jun-2015, tatu: Skip synthetic, bridge methods altogether, for now
             //    at least (add more complex handling only if absolutely necessary)
-            if (Modifier.isStatic(flags)
-                    || m.isSynthetic() || m.isBridge()) {
+            if (Modifier.isStatic(flags) || m.isSynthetic() || m.isBridge() || isGroovyMetaClass(m.getReturnType())) {
                 continue;
             }
             Class<?> argTypes[] = m.getParameterTypes();
@@ -158,12 +157,7 @@ private static void _introspect(Class<?> currType, Map<String, PropBuilder> prop
     }
 
     private static PropBuilder _propFrom(Map<String,PropBuilder> props, String name) {
-        PropBuilder prop = props.get(name);
-        if (prop == null) {
-            prop = Prop.builder(name);
-            props.put(name, prop);
-        }
-        return prop;
+        return props.computeIfAbsent(name, Prop::builder);
     }
 
     private static String decap(String name) {
@@ -182,4 +176,13 @@ private static String decap(String name) {
         return name;
     }
 
+    /**
+     * Helper method to detect Groovy's problematic metadata accessor type.
+     *
+     * @implNote Groovy MetaClass have cyclic reference, and hence the class containing it should not be serialised without
+     * either removing that reference, or skipping over such references.
+     */
+    protected static boolean isGroovyMetaClass(Class<?> clazz) {
+        return "groovy.lang.MetaClass".equals(clazz.getName());
+    }
 }

jr-objects/src/test/groovy/com/fasterxml/jackson/jr/GroovyTest.groovy

@@ -0,0 +1,62 @@
+package com.fasterxml.jackson.jr
+
+import org.junit.Test
+import org.junit.Assert
+
+import com.fasterxml.jackson.jr.ob.JSON
+import com.fasterxml.jackson.jr.ob.TestBase
+
+class GroovyTest
+{
+    @Test
+    void testSimpleGroovyObject() throws Exception {
+        def json = JSON.std.asString(new GroovyOb())
+        def expected = """{"AAAAA_A_Field_Starting_With_Two_Capital_Letters":"XYZ","aDouble":0.0,"aPublicInitializedInteger":56,"aPublicInitializedIntegerObject":1516,"aPublicUninitializedInteger":0,"anInitializedIntegerObject":1112,"anInitializedPublicString":"stringData","anInitializedString":"ABC","anInteger":0,"anIntegerWithValue":12}"""
+        Assert.assertEquals(json, expected)
+    }
+}
+
+class GroovyOb {
+        int anInteger
+        int anIntegerWithValue = 12
+
+        static int anStaticInteger = 34
+        static int anStaticIntegerWithValue = 34
+
+        public int aPublicUninitializedInteger
+        public int aPublicInitializedInteger = 56
+
+        private int aPrivateUninitializedInteger
+        private int aPrivateInitializedInteger = 78
+
+        public static int aPublicStaticUninitializedInteger
+        public static int aPublicStaticInitializedInteger = 910
+
+        Integer anIntegerObject
+        Integer anInitializedIntegerObject = 1112
+
+        static Integer aStaticIntegerObject
+        static Integer aStaticInitializedIntegerObject = 1314
+
+        public Integer aPublicUninitializedIntegerObject
+        public Integer aPublicInitializedIntegerObject = 1516
+
+        public static Integer aPublicStaticUninitializedIntegerObject
+        public static Integer aPublicStaticInitializedIntegerObject = 1718
+
+        String aString
+        String anInitializedString = "ABC"
+
+        static String aStaticString = "jacksonJR"
+
+        public String aPublicString
+        public String anInitializedPublicString = "stringData"
+
+        public String AAAAA_A_Field_Starting_With_Two_Capital_Letters = "XYZ"
+        //Other Items
+        public static String staticStr = "jacksonJR"        // Public Static Object
+        static int anStaticInt                              // Uninitialized Static Object
+        public double aDouble                               // uninitialized primitive
+        public Double aDoubleObject                         // testing boxing object
+        private int hiddenvalue = 123                       // private value
+}

jr-stree/src/main/java/com/fasterxml/jackson/jr/stree/util/JrsTreeTraversingParser.java

@@ -193,10 +193,16 @@ public boolean isClosed() {
      */
 
     @Override
-    public String getCurrentName() {
+    public String currentName() {
         return (_nodeCursor == null) ? null : _nodeCursor.getCurrentName();
     }
 
+    @Override
+    @Deprecated // since 2.17
+    public String getCurrentName() {
+        return currentName();
+    }
+
     @Override
     public void overrideCurrentName(String name)
     {
@@ -211,13 +217,25 @@ public JsonStreamContext getParsingContext() {
     }
 
     @Override
+    public JsonLocation currentTokenLocation() {
+        return JsonLocation.NA;
+    }
+
+    @Override
+    @Deprecated // since 2.17
     public JsonLocation getTokenLocation() {
+        return currentTokenLocation();
+    }
+
+    @Override
+    public JsonLocation currentLocation() {
         return JsonLocation.NA;
     }
 
     @Override
+    @Deprecated // since 2.17
     public JsonLocation getCurrentLocation() {
-        return JsonLocation.NA;
+        return currentLocation();
     }
 
     /*

release-notes/CREDITS-2.x

@@ -23,6 +23,12 @@ Jonas Konrad (@yawkat)
 * Suggested #88: Make `jr-stree` dependency to `jr-objects` optional
  (2.13.0)
 
+Nikolay Chashnikov (@chashnikov)
+
+* Requested #93: Skip serialization of `groovy.lang.MetaClass`
+  values to avoid `StackOverflowError`
+ (2.17.0)
+
 Gerben Oolbekkink (@github)
 
 * Reported #98: `module-info.java` of `jr-stree` refers to module `com.fasterxml.jackson.jr.ob.api`,
@@ -42,5 +48,8 @@ Julian Honnen (@jhonnen)
 
 @Shounaks
 
-* Contributed implf ro #100: Add support for `java.time` (Java 8 date/time) types
+* Contributed fix for #93: Skip serialization of `groovy.lang.MetaClass` values
+  to avoid `StackOverflowError`
+ (2.17.0)
+* Contributed impl for #100: Add support for `java.time` (Java 8 date/time) types
  (2.17.0)

release-notes/VERSION-2.x

@@ -15,6 +15,9 @@ Modules:
 
 #78: Deserializes "null" to "0.0" for `java.lang.Double` (wrapper)
  (reported by @bill-phast)
+#93: Skip serialization of `groovy.lang.MetaClass` values to avoid `StackOverflowError`
+ (requested by Nikolay C)
+ (fix contributed by @Shounaks) 
 #100: Add support for `java.time` (Java 8 date/time) types
  (requested by @sebastian-zero)
  (contributed by @Shounaks)