build important classes for implement system

src/main/java/benefit_classes/DESAlgorithm.java

+package benefit_classes;
+
+import javax.crypto.*;
+import javax.crypto.spec.SecretKeySpec;
+import java.io.UnsupportedEncodingException;
+import java.security.InvalidKeyException;
+import java.security.NoSuchAlgorithmException;
+import java.util.Base64;
+
+public class DESAlgorithm {
+    private SecretKey secretKey;
+
+    public DESAlgorithm(String encodedKey) {                 // The common encodedKey is: fzI0SlHWAfc=
+        // decode the base64 encoded string
+        byte[] decodedKey = Base64.getDecoder().decode(encodedKey);
+        // rebuild key using SecretKeySpec
+        secretKey = new SecretKeySpec(decodedKey, 0, decodedKey.length, "DES");
+    }
+
+    public String encryption(String text) throws NoSuchPaddingException, NoSuchAlgorithmException, UnsupportedEncodingException, IllegalBlockSizeException, BadPaddingException, InvalidKeyException {
+        Cipher desCipher = Cipher.getInstance("DES");
+        desCipher.init(Cipher.ENCRYPT_MODE, secretKey);
+        byte[] textEncrypted = desCipher.doFinal(text.getBytes("UTF-8"));
+        return Base64.getEncoder().encodeToString(textEncrypted);
+    }
+
+    public String decryption(String text) throws NoSuchPaddingException, NoSuchAlgorithmException, InvalidKeyException, UnsupportedEncodingException, IllegalBlockSizeException, BadPaddingException {
+        Cipher desCipher = Cipher.getInstance("DES");
+        desCipher.init(Cipher.DECRYPT_MODE, secretKey);
+        byte[] textDecrypted = desCipher.doFinal(Base64.getDecoder().decode(text));
+        return new String(textDecrypted, "UTF-8");
+    }
+}

src/main/java/benefit_classes/LineSequence.java

+package benefit_classes;
+
+public class LineSequence {
+    private String line;
+    private int sequence;
+
+    public LineSequence(String line, int sequence) {
+        this.line = line;
+        this.sequence = sequence;
+    }
+
+    public void setLine(String line) {
+        this.line = line;
+    }
+
+    public String getLine() {
+        return line;
+    }
+
+    public int getSequence() {
+        return sequence;
+    }
+}
+

src/main/java/benefit_classes/LineSequenceComparator.java

+package benefit_classes;
+
+import java.util.Comparator;
+
+public class LineSequenceComparator implements Comparator<LineSequence> {
+    @Override
+    public int compare(LineSequence s1, LineSequence s2) {
+        if (s1.getSequence() > s2.getSequence())
+            return 1;
+        else if (s1.getSequence() < s2.getSequence())
+            return -1;
+        return 0;
+    }
+}