Third Commit.

Main class created.
UML class diagram added.
input.txt and output.txt added for passing arguments

client/Main.java

@@ -0,0 +1,50 @@
+package client;
+
+import factory.AlgFactory;
+import model.AlgBase;
+
+import java.io.File;
+
+public class Main {
+    public static void main(String[] args) throws Exception {
+        String mode = "enc";
+        String alg = "shift";
+        StringBuilder msg = new StringBuilder();
+        int key = 0;
+        File outputFile = null;
+        File inputFile = null;
+
+        for (int i = 0; i < args.length; i += 2) {
+            switch (args[i]) {
+                case "-mode":
+                    mode = args[i + 1];
+                    break;
+                case "-key":
+                    key = Integer.parseInt(args[i + 1]);
+                    break;
+                case "-data":
+                    msg.append(args[i + 1]);
+                    break;
+                case "-in":
+                    if ("".equals(msg.toString())) {
+                        inputFile = new File(args[i + 1]);
+                    }
+                    break;
+                case "-out":
+                    outputFile = new File(args[i + 1]);
+                    outputFile.createNewFile();
+                    break;
+                case "-alg":
+                    alg = args[i + 1];
+                    break;
+            }
+        }
+
+        AlgBase algorithm = AlgFactory.createAlgorithm(alg, msg.toString(), mode, key);
+        if ("enc".equals(mode)) {
+            algorithm.encrypt(inputFile, outputFile);
+        } else {
+            algorithm.decrypt(inputFile, outputFile);
+        }
+    }
+}