tasks a-s

Task/Rot-13/Java/rot-13.java

@@ -0,0 +1,49 @@
+import java.io.*;
+
+public class Rot13 {
+    public static void main(String[] args) {
+        BufferedReader in;
+        if (args.length >= 1) {
+            for (String file : args) {
+                try {
+                    in = new BufferedReader(new FileReader(file));
+                    String line;
+                    while ((line = in.readLine()) != null) {
+                        System.out.println(convert(line));
+                    }
+                } catch (IOException e) {
+                    e.printStackTrace();
+                }
+            }
+        } else {
+            try {
+                in = new BufferedReader(new InputStreamReader(System.in));
+                String line;
+                while ((line = in.readLine()) != null) {
+                    System.out.println(convert(line));
+                }
+            } catch (IOException e) {
+                e.printStackTrace();
+            }
+        }
+    }
+
+    public static String convert(String msg) {
+        StringBuilder retVal = new StringBuilder();
+        for (char a : msg.toCharArray()) {
+            if (a >= 'A' && a <= 'Z') {
+                a += 13;
+                if (a > 'Z') {
+                    a -= 26;
+                }
+            } else if (a >= 'a' && a <= 'z') {
+                a += 13;
+                if (a > 'z') {
+                    a -= 26;
+                }
+            }
+            retVal.append(a);
+        }
+        return retVal.toString();
+    }
+}