Created class to validate ipv4/6 address and port.

src/main/java/controller/src/Validate/Validate.java

@@ -0,0 +1,69 @@
+/**
+ * @author Aaron Moser
+ * @date 05.12.2023
+ */
+package controller.src.Validate;
+
+import java.util.regex.Matcher;
+import java.util.regex.Pattern;
+
+public class Validate {
+
+    /**
+     * Checks if overhanded string is valid ip address, by checking if its length is 13 or less,
+     * it contains exactly 4 numbers and if the numbers are in valid range.
+     * @param ipv4Address
+     * @return
+     */
+    public static boolean isValidIPv4Address(String ipv4Address) {
+        boolean isValidIPv4Address = false;
+        // Maximum length of ipv4 address is 13 characters, only evaluate if
+        // length of string is less or equal to 13.
+        if (ipv4Address.length() <= 13) {
+            String[] numbersAsString = ipv4Address.split(".");
+            // If ip address contains exactly 4 parts splitted by dots:
+            if (numbersAsString.length == 4) {
+                // Transform each part to integer and check if in valid range.
+                for (String numberAsString : numbersAsString) {
+                    int number = Integer.valueOf(numberAsString);
+                    if (number < 0 || number > 255) {
+                        isValidIPv4Address = false;
+                        break;
+                    }
+                }
+                isValidIPv4Address = true;
+            } else {
+                isValidIPv4Address = false;
+            }
+        }
+        return isValidIPv4Address;
+    }
+
+    /**
+     * Checks if overhanded ipv6 address is valid by applying a regex to it.
+     * @param ipv6Address
+     * @return
+     */
+    public static boolean isValidIPv6Address(String ipv6Address) {
+        Pattern pattern = Pattern.compile("^([0-9a-f]{4}:){7}[0-9a-f]{4}$", Pattern.CASE_INSENSITIVE);
+        Matcher matcher = pattern.matcher(ipv6Address);
+        boolean matchFound = matcher.find();
+        if(matchFound) {
+            return true;
+        } else {
+            return false;
+        }
+    }
+
+    /**
+     * Port is validated by checking if in bounds of overhanded values.
+     * @param port
+     * @param startOfRange
+     * @param endOfRange
+     * @return
+     */
+    public static boolean isValidPort(String port, int startOfRange, int endOfRange) {
+        int portAsInt = Integer.valueOf(port);
+        return (portAsInt >= startOfRange && portAsInt <= endOfRange);
+    }
+}