StringBuilderChainingFailure.java

@BenchmarkMode(Mode.AverageTime)
@Fork(value = 1)
@State(Scope.Thread)
@Warmup(iterations = 5, time = 1)
@OutputTimeUnit(TimeUnit.NANOSECONDS)
@Measurement(iterations = 10, time = 1)
public class StringBuilderChainingFailure {

    String[] sqlColumnNames;

    @Setup
    public void setup() {
        sqlColumnNames = new String[] {"a", "b"};
    }

    @Benchmark
    public String noChaining() {
        final StringBuilder left = new StringBuilder( "(" );
        left.append( String.join( ", ", sqlColumnNames ) );
        return left.append( ")" ).toString();
    }

    @Benchmark
    public String explicitConcat() {
        return "(" + String.join(", ", sqlColumnNames) + ")";
    }

    @Benchmark
    public String explicitConcatImproved() {
        String joinedColumns = String.join(", ", sqlColumnNames);
        return "(" + joinedColumns + ")";
    }

}