# devopsgym / codegen__fasterxml__jackson-databind-4087 - taskset: [devopsgym](https://harnessreport.com/tasks/devopsgym.md) - difficulty: hard - category: code-generation - language: - runnable from the site: no - agent timeout: 3000s ## Results by harness _none yet_ ## Instruction ``` This is a code generation task. You are expected to write working code that solves the described problem. <issue> ### Search before asking - [X] I searched in the [issues](https://github.com/FasterXML/jackson-databind/issues) and found nothing similar. ### Describe the bug Please consider the following trivial Java code: ```java package org.myapp; import com.fasterxml.jackson.databind.ObjectMapper; import java.util.OptionalInt; public class Main { public static void main(final String[] args) throws Exception { final ObjectMapper objectMapper = new ObjectMapper(); final String json = "{ }"; // empty final Data data = objectMapper.readValue(json, Data.class); System.out.println("Read data: " + data); } public static class Data { private OptionalInt value; public Data() { } public void setValue(OptionalInt i) { this.value = i; } public OptionalInt getValue() { return this.value; } @Override public String toString() { return "Data[value=" + this.value + "]"; } } } ``` When using `jackson-databind` `2.15.2` and Java version 17 and running this program, it results in: ```console Caused by: java.lang.reflect.InaccessibleObjectException: Unable to make private java.util.OptionalInt() accessible: module java.base does not "opens java.util" to unnamed module @4cf328c3 at java.lang.reflect.AccessibleObject.throwInaccessibleObjectException (AccessibleObject.java:387) at java.lang.reflect.AccessibleObject.checkCanSetAccessible (AccessibleObject.java:363) at java.lang.reflect.AccessibleObject.checkCanSetAccessible (AccessibleObject.java:311) at java.lang.reflect.Constructor.checkCanSetAccessible (Constructor.java:192) at java.lang.reflect.Constructor.setAccessible (Constructor.java:185) at com.fasterxml.jackson.databind.util.ClassUtil.checkAndFixAccess (ClassUtil.java:995) at com.fasterxml.jackson.databind.deser.impl.CreatorCollector._fixAccess (CreatorCollector.java:278) at com.fasterxml.jackson.databind.deser.impl.CreatorCollector.setDefaultCreator (CreatorCollector.java:130) at com.fasterxml.jackson.databind.deser.BasicDeserializerFactory._addExplicitConstructorCreators (BasicDeserializerFactory.java:438) at com.fasterxml.jackson.databind.deser.BasicDeserializerFactory._constructDefaultValueInstantiator (BasicDeserializerFactory.java:293) at com.fasterxml.jackson.databind.deser.BasicDeserializerFactory.findValueInstantiator (BasicDeserializerFactory.java:222) at com.fasterxml.jackson.databind.deser.BeanDeserializerFactory.buildBeanDeserializer (BeanDeserializerFactory.java:262) at com.fasterxml.jackson.databind.deser.BeanDeserializerFactory.createBeanDeserializer (BeanDeserializerFactory.java:151) at com.fasterxml.jackson.databind.deser.DeserializerCache._createDeserializer2 (DeserializerCache.java:415) at com.fasterxml.jackson.databind.deser.DeserializerCache._createDeserializer (DeserializerCache.java:350) at com.fasterxml.jackson.databind.deser.DeserializerCache._createAndCache2 (DeserializerCache.java:264) at com.fasterxml.jackson.databind.deser.DeserializerCache._createAndCacheValueDeserializer (DeserializerCache.java:244) at com.fasterxml.jackson.databind.deser.DeserializerCache.findValueDeserializer (DeserializerCache.java:142) at com.fasterxml.jackson.databind.DeserializationContext.findNonContextualValueDeserializer (DeserializationContext.java:644) at com.fasterxml.jackson.databind.deser.BeanDeserializerBase.resolve (BeanDeserializerBase.java:539) at com.fasterxml.jackson.databind.deser.DeserializerCache._createAndCache2 (DeserializerCache.java:294) at com.fasterxml.jackson.databind.deser.DeserializerCache._createAndCacheValueDeserializer (DeserializerCache.java:244) at com.fasterxml.jackson.databind.deser.DeserializerCache.findValueDeserializer (DeserializerCache.java:142) at com.fasterxml.jackson.databind.DeserializationContext.findRootValueDeserializer (DeserializationContext.java:654) at com.fasterxml.jackson.databind.ObjectMapper._findRootDeserializer (ObjectMapper.java:4956) at com.fasterxml.jackson.databind.ObjectMapper._readMapAndClose (ObjectMapper.java:4826) at com.fasterxml.jackson.databind.ObjectMapper.readValue (ObjectMapper.java:3772) at com.fasterxml.jackson.databind.ObjectMapper.readValue (ObjectMapper.java:3740) at org.myapp.Main.main (Main.java:10) ``` So `com.fasterxml.jackson.databind.util.ClassUtil` is trying to `setAccessible()` on the private constructor of a JDK class `java.util.OptionalInt`. One way to solve this issue is to configure the `ObjectMapper` instance as follows: ```java objectMapper.configure(MapperFeature.CAN_OVERRIDE_ACCESS_MODIFIERS, false); ``` However, while looking at the code in `com.fasterxml.jackson.databind.util.ClassUtil` I noticed that there's a specific logic which tries to not `setAccessible()` on JDK internal classes here https://github.com/FasterXML/jackson-databind/blob/jackson-databind-2.15.2/src/main/java/com/fasterxml/jackson/databind/util/ClassUtil.java#L994 which looks like: ```java if (!isPublic || (evenIfAlreadyPublic && !isJDKClass(declaringClass))) { ao.setAccessible(true); } ``` Should that `!isJDKClass(declaringClass)` be perhaps applied even when `evenIfAlreadyPublic` is false? Something like: ```java if (!isJDKClass(declaringClass) && (!isPublic || evenIfAlreadyPublic)) { ao.setAccessible(true); } ``` That way, it won't try to access the internal JDK classes and run into these exceptions on Java 17+? ### Version Information 2.15.2 ### Reproduction _No response_ ### Expected behavior _No response_ ### Additional context _No response_ </issue> Focus on implementing the required functionality correctly and efficiently. Treat this as a programming challenge. You are not allowed to read git history. ``` --- Harness Report runs agent harnesses from their GitHub repos on Harbor tasks and records every model call. Every page is also `.md` and `.json`; index: https://harnessreport.com/llms.txt · MCP: https://harnessreport.com/mcp