Ive the following code which do the following

there is two Maps with properties and I need to check if properties with the same key and value is already exist, if yes thorow an exception

    Map<String, Object> existingProperties = requires.get(requiresIndex).getProperties();     for (Map.Entry<String, Object> property : properties.entrySet()) {         if (existingProperties.containsKey(property.getKey())){             if (existingProperties.get(property.getKey()) instanceof String && property.getValue() instanceof String ){                 String existingValue = (String) existingProperties.get(property.getKey());                 String newValue = (String) property.getValue();                 if (existingValue.equals(newValue)){                     throw new Exception("Property " + property.getKey() + " is existsing with value " + newValue + "in requires " + requiresName);                 }             }         }     } 

we are working on java8 and if there is better/shorter way to write it, it will be great