Splicing strings in the string collection_ Stream based

Splicing String String in collection

1. Existing string collection “ Zhang San ” 、“ Li Si ” 、“ Wang Wu ”、“”、null, Now you need to separate the strings in the collection with commas , Concatenate into a string .

   public class Main2 {
         
       public static void main(String[] args) {
         
           Set<String> studentNameSet = new HashSet<>(5);
           studentNameSet.add(" Zhang San ");
           studentNameSet.add(" Li Si ");
           studentNameSet.add(" Wang Wu ");
           studentNameSet.add("");
           studentNameSet.add(null);
   
           String studentNameString = studentNameSet
                   .stream()
                   .filter(name -> name != null && name.length() > 0)
                   .collect(Collectors.joining(","));
   
           System.out.println(studentNameString);
       }
   }
   

   Output results ：

    Li Si , Zhang San , Wang Wu 
   

   Be careful ：

   • Use filters to filter invalid data ;
   • Filter can be connected ：filter().filter().filter()…….;