Add my first solution for part 2

day_01/java/part_2.java

@@ -0,0 +1,44 @@
+import java.io.File;
+import java.io.FileNotFoundException;
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.Scanner;
+
+class Part2 {
+	public static void main (String[] args) {
+		Scanner f;
+		try {
+			f = Part2.readFile(args[0]);
+		} catch (FileNotFoundException e) {
+			System.out.println("File not found, stopping execution");
+			return;
+		}
+
+		ArrayList<Integer> sums = new ArrayList<Integer>();
+		Integer runningSum = 0;
+		while (f.hasNextLine()) {
+			String l = f.nextLine();
+			if (l.equals("")) {
+				sums.add(runningSum);
+				runningSum = 0;
+			} else {
+				runningSum = runningSum + Integer.parseInt(l);
+			}
+		}
+		f.close();
+
+		Collections.sort(sums, Collections.reverseOrder());
+		System.out.print(
+			"The largest three values are: "
+			+ sums.subList(0, 3).toString()
+			+ " totalling: "
+		);
+		System.out.println(sums.get(0) + sums.get(1) + sums.get(2));
+	}
+
+	private static Scanner readFile(String file) throws FileNotFoundException {
+		File f = new File(file);
+		Scanner s = new Scanner(f);
+		return s;
+	}
+}