mirror of
https://github.com/alirezarezvani/claude-skills.git
synced 2026-09-08 22:21:12 +00:00
14c645ba16
- Extract commun languages rules in a separate rules/universal.md containing all cross-language rules in one place - Move language-specific rules inline into each languages/*.md file, organised into consistent sections: Security / Async / Resource Management / Exception Handling / Performance / Idioms - Add Java support: languages/java.md with full section coverage - Every review now requires exactly 2 file reads: universal.md + one language file - Add "Adding a new language" guide to SKILL.md: one file to create, nothing else changes
103 lines
4.3 KiB
Markdown
103 lines
4.3 KiB
Markdown
---
|
|
language: java
|
|
extensions: [".java"]
|
|
---
|
|
|
|
# Java — Language-Specific Review Notes
|
|
|
|
Load this file alongside `rules/universal.md`. Universal rules are not repeated here — only Java-specific rules and idioms.
|
|
|
|
---
|
|
|
|
## PR Analyzer — Java Risk Signals
|
|
|
|
- `System.out.println` / `e.printStackTrace()` left in production code
|
|
- `@SuppressWarnings` annotations — verify they are justified
|
|
- Hardcoded JDBC URLs or credentials in source
|
|
- Raw type usage (`List`, `Map` without generics)
|
|
|
|
---
|
|
|
|
## Code Quality — Java Checks
|
|
|
|
- Empty `catch` blocks swallowing exceptions silently
|
|
- Checked exceptions caught and not re-thrown with context
|
|
- `Closeable` / `AutoCloseable` resources not in try-with-resources
|
|
- Raw type usage — defeats generics type safety
|
|
- Missing `@Override` on overriding methods
|
|
- `InterruptedException` caught without calling `Thread.currentThread().interrupt()`
|
|
|
|
---
|
|
|
|
## Security
|
|
|
|
- Flag JPQL / HQL or native SQL string concatenation — require named parameters or `CriteriaBuilder`
|
|
- Flag `@RequestMapping` without explicit HTTP method restriction on state-changing endpoints
|
|
- Flag user-controlled input passed to `Runtime.exec()` or `ProcessBuilder` without validation
|
|
- Flag `ObjectInputStream.readObject()` on untrusted data — unsafe deserialization
|
|
- Flag hardcoded JDBC URLs or credentials — require environment variables or a vault
|
|
|
|
---
|
|
|
|
## Async / Concurrency
|
|
|
|
- Flag `ExecutorService.submit()` return value ignored — exceptions are swallowed
|
|
- Flag `Thread.sleep()` used as a synchronization mechanism — use `CountDownLatch`, `CompletableFuture`, or `await()`
|
|
- Flag `CompletableFuture` chains with no `.exceptionally()` or `.handle()` terminal handler
|
|
- Flag `InterruptedException` caught without calling `Thread.currentThread().interrupt()`
|
|
- Flag `synchronized` on a non-final field — the lock object can be replaced
|
|
- Flag `HashMap` used in multi-threaded context — use `ConcurrentHashMap`
|
|
|
|
---
|
|
|
|
## Resource Management
|
|
|
|
- Flag `InputStream`, `OutputStream`, `Connection`, `ResultSet`, `PreparedStatement` not wrapped in try-with-resources
|
|
- Flag manual `finally { resource.close() }` — replace with try-with-resources
|
|
- Flag `HttpURLConnection` not disconnected after use
|
|
- Flag JDBC `Connection` obtained from a pool and not returned (missing `close()`) on all paths
|
|
- Flag `static` `HttpClient` or `Connection` fields shared across threads without connection pool management
|
|
|
|
---
|
|
|
|
## Exception Handling
|
|
|
|
- Flag empty `catch` blocks — `catch (Exception e) {}`
|
|
- Flag `InterruptedException` caught without `Thread.currentThread().interrupt()` — breaks cooperative cancellation
|
|
- Flag checked exceptions swallowed in a `catch` and not re-thrown or logged with context
|
|
- Flag `throw new RuntimeException(e)` without a descriptive message — loses context
|
|
- Flag `printStackTrace()` as the sole error handling — use a proper logger
|
|
|
|
---
|
|
|
|
## Performance
|
|
|
|
- Flag `String` concatenation in loops — use `StringBuilder`
|
|
- Flag `List.contains()` / `Map.get()` in a loop on large collections — review data structure choice
|
|
- Flag N+1 JPA / Hibernate queries — use `JOIN FETCH` or `@BatchSize`
|
|
- Flag `new ObjectMapper()` / `new Gson()` instantiated per-request — share a singleton
|
|
- Flag `ResultSet` fully iterated when only the first result is needed — use `LIMIT 1` in the query
|
|
|
|
---
|
|
|
|
## Idioms and Best Practices
|
|
|
|
### Null Safety
|
|
- Prefer returning `Optional<T>` over `null` from methods
|
|
- Flag unchecked dereferences without a prior null guard
|
|
- Do not catch `NullPointerException` — fix the root cause instead
|
|
|
|
### Collections and Streams
|
|
- Flag `==` used to compare `String` or boxed types — use `.equals()`
|
|
- Flag `.collect(Collectors.toList())` where `.toList()` (Java 16+) suffices
|
|
- Flag premature `.stream().collect()` round-trips that could be a single-pass operation
|
|
|
|
### Generics
|
|
- Flag raw types in any new code — always parameterize (`List<String>`, not `List`)
|
|
- Flag unchecked cast warnings suppressed without explanation
|
|
|
|
### Modern Java (11+)
|
|
- Prefer `var` for local variables where the type is obvious from the right-hand side
|
|
- Prefer records for pure data carriers over manual POJOs with getters/setters
|
|
- Prefer `instanceof` pattern matching (`if (obj instanceof String s)`) over explicit casts
|
|
- Prefer `switch` expressions over `switch` statements where a value is returned
|