我有以下方法在我的数据库中遇到某种故障。没有错误被写入我的控制台，所以我很困惑。我正在使用 JDBC 和 Google AppEngine。任何人都可以帮助我吗？谢谢。
public List<Bulletin> getApprovedBulletins() {
List<Bulletin> bulletins = new ArrayList<Bulletin>();
try {
Connection connection = getConnection();
Statement statement = connection.createStatement();
statement.executeQuery("select * from bulletins where approved = true");
ResultSet resultSet = statement.getResultSet();
while (resultSet.next()) {
Bulletin bulletin = new Bulletin();
bulletin.setId(resultSet.getInt("id"));
bulletin.setDate(resultSet.getDate("bulletin_date"));
bulletin.setName(resultSet.getString("name"));
bulletin.setSubject(resultSet.getString("subject"));
bulletin.setNote(resultSet.getString("bulletin"));
bulletins.add(bulletin);
}
resultSet.close();
connection.close();
return bulletins;
}
catch (Exception e) {
System.out.println(e.toString());
}
return null;
}
private Connection getConnection() {
Connection conn = null;
String url = "jdbc:mysql://localhost:3306/cpc";
String driver = "com.mysql.jdbc.Driver";
String userName = "root";
String password = "password";
try {
Class.forName(driver).newInstance();
conn = DriverManager.getConnection(url, userName, password);
} catch (Exception e) {
return null;
}
return conn;
}