Applying regex to Java8 List<String> - regex

Question

I have an array list
List<String> items = Arrays.asList("date=2017-01-10", "date=2017-02-10");
I want to convert this list and have quotes for each item in the list so
date=2017-01-10 can be converted to date='2017-01-10'
List<String> items = Arrays.asList("date='2017-01-10'", "date='2017-02-10'");
How can i do in Java 8 ?
UPDATE: I want to use regex to achieve this.

Answer 1

You can use replaceAll with this regex ^(.*?)=(.*?)$ which return two groups one before the = the second after, so you can replace the input with group 1 $1 followed by =' then group 2 between two quotes '$2':
List<String> items = Arrays.asList("date=2017-01-10", "date=2017-02-10");
items = items.stream()
.map(t -> t.replaceAll("(.*?)=(.*?)$", "$1='$2'"))
.collect(Collectors.toList());
items.forEach(System.out::println);
Outputs
date='2017-01-10'
date='2017-02-10'

Answer 2

I have seen your profile, I found you start to Java. so I'll give you the answer just for learning purpose.
use lookbehind to skip replacement. e.g: (?<==)
use group to capture the matched result in group, e.g: (.+)
use $ sign to references to captured group, e.g: $1.
List<String> result = items.stream()
// match `=` ---v
.map(it -> it.replaceFirst("(?<==)(.+)", "'$1'"))
// capture the rest substring in group ---^
.collect(Collectors.toList());
You also can simply to use String#substring to achieve your way. for example:
int prefix = "date=".length();
List<String> result =items.stream()
.map(it->String.format("date='%s'",it.substring(prefix)))
.collect(Collectors.toList());

Answer 3

you can use the following code
List<String> items = Arrays.asList("date=2017-01-10", "date=2017-02-10"), result = new ArrayList<String>();
for(String item : items){
item = item.replace("date=", "date='");
item = item + "'";
result.add(item);
}
for(String item : result){
System.out.println(item);
}
demo