Représentation d'un fragment d'ADN (String ou StringBuffer ?)

import java.util.function.*;

public class Test {

    private static final int NB_CHARS = 2000, NB_LOOP = 1000;

    public static <E> void test(String s, Supplier<E> init,
BiFunction<E, Character, E> appender, Function<E, E> finish) {
        long time = 0;
        for (int retry = 0; retry < NB_LOOP; retry++) {
            E chars = init.get();
            time -= System.nanoTime();
            for (char c = 0; c < NB_CHARS; c++) {
                chars = appender.apply(chars, c);
            }
            chars = finish.apply(chars);
            time += System.nanoTime();
        }
        System.out.printf("%s\n\t%.0f µs\n", s, time * 1e-3 / NB_LOOP);
    }

    public static void main(String[] args) {
        test("String +=", () -> "", (s, c) -> s += c, s -> s);

        test("StringBuffer().insert",
() -> new StringBuffer(), (s, c) -> s.insert(0, c), s -> s);
        test("StringBuffer(size).insert",
() -> new StringBuffer(NB_CHARS), (s, c) -> s.insert(0, c), s -> s);
        test("StringBuffer().append+reverse",
() -> new StringBuffer(), (s, c) -> s.append(c), s -> s.reverse());
        test("StringBuffer(size).append+reverse",
() -> new StringBuffer(NB_CHARS), (s, c) -> s.append(c), s -> s.reverse());

        test("StringBuilder().insert",
() -> new StringBuilder(), (s, c) -> s.insert(0, c), s -> s);
        test("StringBuilder(size).insert",
() -> new StringBuilder(NB_CHARS), (s, c) -> s.insert(0, c), s -> s);
        test("StringBuilder.append+reverse",
() -> new StringBuilder(), (s, c) -> s.append(c), s -> s.reverse());
        test("StringBuilder(size).append+reverse",
() -> new StringBuilder(NB_CHARS), (s, c) -> s.append(c), s -> s.reverse());
    }
}

String +=
 1149 µs
StringBuffer().insert
 233 µs
StringBuffer(size).insert
 224 µs
StringBuffer().append+reverse
 86 µs
StringBuffer(size).append+reverse
 78 µs
StringBuilder().insert
 211 µs
StringBuilder(size).insert
 192 µs
StringBuilder.append+reverse
 47 µs
StringBuilder(size).append+reverse
 44 µs