what is the Java equivalent of sscanf for parsing values from a string using a known pattern?

The problem is Java hasn't out parameters (or passing by reference) as C or C#.

But there is a better way (and more solid). Use regular expressions:

Pattern p = Pattern.compile("(\\d+)-(\\p{Alpha}+)-(\\d+) (\\d+)\\.(\\d+)\\.(\\d+)\\.(\\d+)")
Matcher m = p.matcher("17-MAR-11 15.52.25.000000000");
day = m.group(1);
month= m.group(2);
....

Of course C code is more concise, but this technique has one profit: Patterns specifies format more precise than '%s' and '%d'. So you can use \d{2} to specify that day MUST be compose of exactly 2 digits.

Here is a solution using scanners:

Scanner scanner = new Scanner("17-MAR-11 15.52.25.000000000");

Scanner dayScanner = new Scanner(scanner.next());
Scanner timeScanner = new Scanner(scanner.next());

dayScanner.useDelimiter("-");
System.out.println("day=" + dayScanner.nextInt());
System.out.println("month=" + dayScanner.next());
System.out.println("year=" + dayScanner.nextInt());

timeScanner.useDelimiter("\\.");
System.out.println("hour=" + timeScanner.nextInt());
System.out.println("min=" + timeScanner.nextInt());
System.out.println("sec=" + timeScanner.nextInt());
System.out.println("fracpart=" + timeScanner.nextInt());

None of these examples were really satisfactory to me so I made my own java sscanf utility:

https://github.com/driedler/java-sscanf/tree/master/src/util/sscanf

Here's an example of parsing a hex string:

String buffer = "my hex string: DEADBEEF\n"
Object output[] = Sscanf.scan(buffer, "my hex string: %X\n", 1);

System.out.println("parse count: " + output.length);
System.out.println("hex str1: " + (Long)output[0]);

// Output:
// parse count: 1
// hex str1: 3735928559