How to make List read-only

Sometimes we need that no element should be added or deleted from our collections.

Then we should follow this stratigity

List<String> list=new ArrayList<>();


list = Collections.unmodifiableList(list);

simillary for set and map


map = Collections.unmodifiableMap(map);

And remember  if you try to add element  this will not give compiler error but java.lang.UnsupportedOperationException


Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Google+ photo

You are commenting using your Google+ account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )


Connecting to %s