Choose the decision supported by each API contract. These are local self-check questions.
Read the lessons
- Java walkFileTree: visit failures without hiding incomplete scans
- Java WatchService: register, consume, and reset each key
- Java WatchService OVERFLOW: reconcile against directory state
- Java DirectoryStream: close iteration and reject silent truncation
- Java symbolic links: inspect attributes without claiming race safety
- Java JDBC batches: inspect update counts and own rollback
- Java ResultSet: cursor position and SQL NULL are separate states
- Java JDBC generated keys: validate one insert and one returned identity
- Java JDBC fetch size: a hint, not a memory guarantee
- Java ProcessBuilder: pass command tokens without a shell
- Java Process.waitFor timeout: terminate and reap the owned child
Common Mistakes
Do not mistake an observed event, returned key, or hint for a committed and complete result.