Connection management
Database connections are expensive resources that must be closed properly to avoid memory leaks. Java's try-with-resources syntax automatically closes connections, statements, and result sets when the block completes, even if errors occur.
Ensure CityBook Libraries' application manages resources safely.
To ćwiczenie jest częścią kursu
Querying a PostgreSQL Database in Java
Instrukcje do ćwiczenia
- Wrap resources in a try-with-resources block.
- Add exception handling for database errors.
Interaktywne ćwiczenie praktyczne
Spróbuj tego ćwiczenia, uzupełniając ten przykładowy kod.
public class Main {
public static void main(String[] args) {
// Use try-with-resources for automatic cleanup
____ (Connection conn = DriverManager.getConnection(Credentials.URL, Credentials.USER, Credentials.PASSWORD);
Statement stmt = conn.createStatement();
ResultSet rs = stmt.executeQuery("SELECT * FROM books")) {
while (rs.next()) {
System.out.println(rs.getString("title"));
System.out.println(rs.getInt("publication_year"));
}
// Handle database exceptions
} ____ (SQLException e) {
System.out.println("Error: " + e.getMessage());
System.out.println("SQLState: " + e.getSQLState());
}
}
}