Construct JSON path only on exceptional cases.

[guidobrei]

This pull request addresses issue #63: Excessive object and memory allocations from string format operations during JSON logic evaluation.

Summary of Improvements

• Optimized jsonPath Construction:
  Now, jsonPath is built only when exceptions are thrown, not on every evaluation step.
• Reduced Usage of String.format:
  Frequent string formatting—previously responsible for a large portion of memory allocation—is now minimized.
• Efficient String Manipulation:
  Refactored string handling within the evaluation logic for improved efficiency.
• Decreased Unnecessary Object Creation:
  Memory profiles should reflect reduced object churn and overall improved allocation patterns.
• No breaking changes:
  The public interfaces have not been changed. The change should not break any dependent library.

Benefits

• Lower Memory Footprint:
  Dramatically reduces allocations related to string operations, easing runtime memory pressure.
• Improved Performance:
  Faster evaluations due to fewer expensive object and string operations.
• Better Scalability:
  Enhanced library stability and efficiency under heavy or high-throughput usage.
• Targeted Exception Diagnostics:
  jsonPath remains available for error handling and diagnostics, but is computed only as needed.

[guidobrei]

@jamsesso, @magnarn this is a proposal to reduce the memory footprint of the evaluation again.

It effectively makes the jsonPath property introduced in #53 obsolete again. I did not remove it for backwards compatibility.
WDYT?

[magnarn]

I think this is awesome!

Thanks for fixing it. I wish I had though of this when introducing the json path.

[guidobrei]

I've added additional tests to cover malformed expressions.

[guidobrei]

@jamsesso any chance we could fix the issue soon?

[chrfwow]

@jamsesso any updates?

[gzsombor]

I imagine you’re also interested in the library’s performance, so you might be interested to know that I created a fork based on this branch, where I further improved the code by using Java’s internal compiler to translate the JSON rules into Java classes, which allowed me to achieve a 3- to 8-fold performance increase (in terms of execution speed). The new library is compatible with the old API, so you only need to change the groupId of the dependency in your project.
For simplicity's sake, however, Java 23 is required (it would probably work with earlier versions as well, but that was the requirement for me). At the moment, it seems to work for the tasks I'm using it for; if anyone else tries it out, I'd appreciate your feedback.
If this library is ever maintained again, I would of course be happy to submit my changes,

So my repo is at : https://github.com/gzsombor/json-logic-java