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Java 8 Streams - Collectors.joining Examples

Java 8 Streams Java Java API 

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java.lang.Objectjava.lang.Objectjava.util.stream.Collectorsjava.util.stream.CollectorsLogicBig

The overloaded static methods, Collector#joining() return a Collector that concatenates the input element strings into a single String.

Collector<CharSequence,?,String> joining()


Collector<CharSequence,?,String> joining(CharSequence delimiter)


Collector<CharSequence,?,String> joining(CharSequence delimiter,

                                         CharSequence prefix,

                                         CharSequence suffix)

Parameters

delimiter : This is used between the two concatenated elements.

prefix: This is appended at the beginning of the output.

suffix: This is appended at the end of the output.


Examples


package com.logicbig.example.collectors;

import java.util.stream.Collectors;
import java.util.stream.Stream;

public class JoiningExample {
    public static void main (String[] args) {
        Stream<String> s = Stream.of("what", "so", "ever");
        String str = s.collect(Collectors.joining());
        System.out.println(str);
    }
}

Output

whatsoever
Original Post




package com.logicbig.example.collectors;

import java.util.stream.Collectors;
import java.util.stream.Stream;

public class JoiningExample2 {
    public static void main (String[] args) {
        Stream<String> s = Stream.of("what", "so", "ever");
        String str = s.collect(Collectors.joining("|"));
        System.out.println(str);
    }
}

Output

what|so|ever
Original Post




package com.logicbig.example.collectors;

import java.util.stream.Collectors;
import java.util.stream.Stream;

public class JoiningExample3 {
    public static void main (String[] args) {
        Stream<String> s = Stream.of("what", "so", "ever");
        String str = s.collect(Collectors.joining("|", "-", "!"));
        System.out.println(str);
    }
}

Output

-what|so|ever!
Original Post

See Also