adam bien's blog

import java.util.StringJoiner;
import static org.hamcrest.CoreMatchers.is;
import static org.junit.Assert.assertThat;
import org.junit.Test;

public class StringJoinerTest {

    @Test
    public void join() {
        String expected = "duke,java";
        StringJoiner sj = new StringJoiner(",");
        sj.add("duke").add("java");
        String actual = sj.toString();
        assertThat(actual, is(expected));
    }

    @Test
    public void shortCut() {
        String expected = "duke,java";
        String actual = String.join(",", "duke", "java");
        assertThat(actual, is(expected));

    }
}

Thanks to @gschmidl for the idea:

@AdamBien or just String.join(",", list);

— Gunther Schmidl (@gschmidl) April 15, 2014

See you at Java EE Workshops at MUC Airport or on demand and in a location very near you: airhacks.io!