Use DateTimeFormatter to convert between a date string and a real LocalDateTime object. with a LocalDateTime as starting point, you can easily apply formatting based on various patterns as definied in the javadoc of the DateTimeFormatter.
String originalString = "2010-07-14 09:00:02";
LocalDateTime dateTime = LocalDateTime.parse(originalString, DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm:ss"));
String newString = DateTimeFormatter.ofPattern("H:mm").format(dateTime); // 9:00
In case you’re not on Java 8 or newer yet, use SimpleDateFormat to convert between a date string and a real Date object. with a Date as starting point, you can easily apply formatting based on various patterns as definied in the javadoc of the SimpleDateFormat.
String originalString = "2010-07-14 09:00:02";
Date date = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss").parse(originalString);
String newString = new SimpleDateFormat("H:mm").format(date); // 9:00