Remove space from a list object while iterating using Java 8

Question

This is my code , which is returning spaces along with some valid strings. But, my requirement is to invalidate space and collect only strings

List<String> stateCodes = stateList.stream()
                                    .map(state-> physician.getStateDetails().getStateCode())
                                    .collect(Collectors.toList());

When I print stateCodes, it returns

[ ,  , 197, 148,  ,  ,  ,  ,  ,  ,  ,  ,  ,  ,  ,  ,  ,  ,  ,  ,  ,  ,  ,  ,  ,  ,  ,  ,  ,  ,  ,  ,  ,  ,  ,  ,  ,  ,  ,  ,  ,  ,  ,  ,  ,  ,  ,  ,  ,  ]

Here I require only [197,148]

Use the filter method to only return those elements that fit your needs — jSebestyén
– jSebestyén, Commented Jan 20, 2020 at 7:47

Eran · Accepted Answer · 2020-01-20 08:02:51Z

7

Filter out the empty values. I'm not sure if those are empty Strings in your output. If they are, you can filter them out with:

List<String> stateCodes =
    stateList.stream()
             .map(state-> physician.getStateDetails().getStateCode())
             .filter(s -> !s.isEmpty())
             .collect(Collectors.toList());

Note: you can add trim() (to either the map or filter steps) to filter out Strings which contain only white spaces:

List<String> stateCodes =
    stateList.stream()
             .map(state-> physician.getStateDetails().getStateCode().trim())
             .filter(s -> !s.isEmpty())
             .collect(Collectors.toList());

edited Jan 20, 2020 at 8:02

answered Jan 20, 2020 at 7:47

Eran

395k57 gold badges726 silver badges793 bronze badges

Sign up to request clarification or add additional context in comments.

7 Comments

Sudhir Ojha Over a year ago

Good answer. Only one doubt if physician.getStateDetails().getStateCode() have a space.

Syed Over a year ago

Sudhir, use StringUtils.IsNotEmpty

Eran Over a year ago

@SudhirOjha in that case, you have to change the filter Predicate to something like s -> !s.trim().isEmpty()

Hadi Over a year ago

No need to trim() in .map(....) or remove it from filter(...)

Youcef LAIDANI Over a year ago

Or filter(String::isBlank) from Java11

|

Iosif Pop · Accepted Answer · 2020-01-20 08:00:27Z

2

You should trim the strings first, after that filter by isEmpty and collect.

answered Jan 20, 2020 at 8:00

Iosif Pop

3822 silver badges15 bronze badges

Comments

Idan Str · Accepted Answer · 2020-01-20 08:19:10Z

0

I will do:

List<String> stateCodes =
stateList.stream()
         .map(state-> physician.getStateDetails().getStateCode())
         .filter(s -> !s.trim().isEmpty())
         .collect(Collectors.toList());

I add a filter on data and remove the empty data - used trim only in predicate.

edited Jan 20, 2020 at 8:19

answered Jan 20, 2020 at 8:13

Idan Str

6141 gold badge11 silver badges33 bronze badges

Collectives™ on Stack Overflow

Remove space from a list object while iterating using Java 8

3 Answers 3

7 Comments

Comments

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

3 Answers 3

7 Comments

Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Related