Missing cleanup contract (ARCH4082)

Key java.performance.dispose-pattern · Severity warning · Category performance

If a class holds an AutoCloseable field but does not itself implement AutoCloseable, there is no way to release the resource it owns, so it leaks.

Incorrect

public class Repository {
    private final Connection conn = openConnection();
    // no way to close conn
}

Correct

public class Repository implements AutoCloseable {
    private final Connection conn = openConnection();

    @Override
    public void close() throws SQLException {
        conn.close();
    }
}

Fix

Implement AutoCloseable on classes owning closeable fields and close those fields in close().