upload

src/main/java/hhn/temp/project/TaskManager.java

@@ -17,6 +17,10 @@ public class TaskManager {
 
   public Task createTask(String name, String description) {
 
+    if(!checkOnlyLetterOrDigit(name)) {
+      throw new TaskAlreadyExistsException("Only Letters or Digit are allowed in the name: " + name);
+    }
+
     boolean taskExited = this.taskMap.values().stream().anyMatch(task -> task.getName().equals(name));
     if(taskExited) {
       throw new TaskAlreadyExistsException("Task already exits, with the name: " + name);
@@ -55,4 +59,29 @@ public class TaskManager {
             .orElseThrow().getTaskID());
 
   }
+
+  private boolean checkOnlyLetterOrDigit(String text) {
+    boolean result = true;
+
+    for(int i = 0; i < text.length(); i++) {
+      char c = text.charAt(i);
+      if(!Character.isLetterOrDigit(c)) {
+        result = false;
+        break;
+      }
+    }
+    return result;
+  }
+  private boolean checkOnlyLetter(String text) {
+    boolean result = true;
+
+    for(int i = 0; i < text.length(); i++) {
+      char c = text.charAt(i);
+      if(!Character.isLetter(c)) {
+        result = false;
+        break;
+      }
+    }
+    return result;
+  }
 }