Error Handling

[jnguyen095]

1. Use Exceptions Rather Than Return Codes
2. Write Your Try-Catch-Finally Statement First
3. Use Unchecked Exceptions
4. Provide Context with Exceptions
5. Define Exception Classes in Terms of a Caller’s Needs
6. Don’t Return Null, if null return an empty collection

public List<Employee> getEmployees() {
    if( .. there are no employees .. )
      return Collections.emptyList();
}

7. Don’t Pass Null

public double xProjection(Point p1, Point p2) {
    if (p1 == null || p2 == null) {
      throw InvalidArgumentException(
        "Invalid argument for MetricsCalculator.xProjection");
    }
    return (p2.x – p1.x) * 1.5;
    }
}