[dlunch]

Changes

• Enforce Java null contracts across String, array copying, exception output, numeric decoding, class loaders, URL connections, and ZIP/JAR APIs without Rust panics.
• Validate I/O arguments and nullable backing streams while preserving valid empty operations. Keep standard file descriptors non-null when host streams are unavailable, reporting IOException on use.
• Preserve nullable calendar/date-format setters and handle subsequent operations safely, including numeric parsing and literal-only input.
• Add integration regressions for rejected and permitted null inputs, empty operations, and recovery from nullable state.

Verification

• Workspace tests: 577 passed, 2 ignored.
• Native all-targets and wasm32-unknown-unknown Clippy checks passed with warnings denied.
• Formatting and diff checks passed.

Wasm execution was not tested.

[chatgpt-codex-connector]

Codex Review Summary

This comment shows the latest Codex review activity on this pull request.

Review	Status	Commit	Review trigger
📝 Code Review	✅ Completed 2026-10-24T09:49:16.080616Z	11973e4	PR opened

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[codecov]

Codecov Report

❌ Patch coverage is 92.55583% with 30 lines in your changes missing coverage. Please review.
✅ Project coverage is 87.78%. Comparing base (a848a99) to head (11973e4).

Files with missing lines	Patch %	Lines
...untime/src/classes/java/text/simple_date_format.rs	72.72%	15 Missing ⚠️
...runtime/src/classes/java/io/filter_input_stream.rs	86.11%	5 Missing ⚠️
...-runtime/src/classes/java/io/data_output_stream.rs	94.54%	3 Missing ⚠️
...untime/src/classes/java/io/filter_output_stream.rs	86.36%	3 Missing ⚠️
...a-runtime/src/classes/java/io/data_input_stream.rs	95.00%	1 Missing ⚠️
...-runtime/src/classes/java/io/random_access_file.rs	94.44%	1 Missing ⚠️
...ustjava-runtime/src/classes/java/lang/throwable.rs	83.33%	1 Missing ⚠️
...tjava-runtime/src/classes/java/text/date_format.rs	94.44%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #226      +/-   ##
==========================================
+ Coverage   87.31%   87.78%   +0.46%     
==========================================
  Files         311      311              
  Lines       46772    47092     +320     
==========================================
+ Hits        40841    41338     +497     
+ Misses       5931     5754     -177     

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[Copilot]

🔵 Needs a closer look

The change spans ~40 files and alters cross-cutting runtime semantics (standard stream initialization and multiple Java exception contracts), which warrants final human review despite the added test coverage.

No open issues 🎉

What changed in this PR

This PR hardens the RustJava runtime so Java null contracts are enforced with proper Java exceptions instead of Rust panics, and reworks standard-stream initialization. Across java.lang, java.io, java.net, java.text, java.util, and org.rustjava classes, nullable references are now validated and converted into NullPointerException (or MalformedURLException) before any dereference. FileDescriptor.<clinit> now always publishes non-null in/out/err descriptors (leaving fd=0 when the host stream is unavailable, which surfaces as IOException on use), so System.<clinit> no longer needs to guard stdin. It also corrects Integer/Long.decode(null) to throw NullPointerException (not NumberFormatException), makes calendar/date-format setters tolerate null and fail safely on later use, and adds extensive regression tests.

Changes:

• Add explicit null validation to runtime APIs (String, arraycopy, I/O streams, URL/handler/class-loader, ZIP/JAR, numeric decode) that previously risked panics.
• Keep standard file descriptors non-null when host streams are missing and report IOException only on actual use; allow nullable calendar/number-format state with safe downstream failure.
• Add integration tests covering rejected nulls, permitted empty operations, and recovery from nullable state.

File	Description
io/​file_descriptor.rs	Always creates non-null in/out/err descriptors (fd=0 when host stream unavailable).
lang/​system.rs	Drops stdin null guard (now always non-null); adds arraycopy null check.
util/​calendar.rs, util/​gregorian_calendar.rs	Nullable setTimeZone; identity/null-tz handling in equals; NPE in get/hashCode/compute on null tz.
text/​simple_date_format.rs	Adds DateParseError enum and null-numberFormat NPE path; NPE on null calendar/timeZone/numberFormat.
text/​date_format.rs	Setters accept null; get/set/isLenient/clone throw NPE when backing state is null.
lang/​string.rs	Null checks for byte/char/String/StringBuffer constructors, concat, getChars.
lang/​integer.rs, lang/​long.rs	decode(null) now throws NullPointerException.
lang/​class_loader.rs, lang/​throwable.rs	Null checks for loadClass/getResource and printStackTrace.
net/​url.rs, net/​url_stream_handler.rs, net/​url_class_loader.rs, net/​jar_url_connection.rs	Reject null spec/url/array/name with appropriate exceptions.
io/​filter_input_stream.rs, io/​filter_output_stream.rs, io/​data_input_stream.rs, io/​data_output_stream.rs	Guard null underlying stream and null/empty arguments; preserve valid empty ops.
io/​file.rs, io/​file_input_stream.rs, io/​file_output_stream.rs, io/​random_access_file.rs, io/​reader.rs, io/​writer.rs, io/​input_stream_reader.rs, io/​output_stream_writer.rs, io/​buffered_output_stream.rs	Null checks on constructor/read/write arguments.
util/​zip/​zip_file.rs, util/​zip/​zip_entry.rs, org/​rustjava/​lang/​rust_jar_class_loader.rs, org/​rustjava/​net/​file_url_handler.rs, org/​rustjava/​net/​url_path.rs	Reject null file/entry/name/url/path.
tests/​classes/​** (io, lang, net, text, util, org)	New regression tests for null rejection, empty-op acceptance, and recovery.

_{Review effort: Balanced}