Benchmarking SLF4J placeholders vs plain old concatenation.

PlaceholdersBenchmark.java

import org.slf4j.helpers.MessageFormatter;

import com.google.caliper.Benchmark;
import com.google.caliper.Param;
import com.google.caliper.runner.CaliperMain;

public final class PlaceholdersBenchmark extends Benchmark {
	public static void main(String[] args) {
		CaliperMain.main(PlaceholdersBenchmark.class, args);
	}

	private enum MessageCreator {
		CONCATENATION {
			@Override
			String create(int x) {
				return "hello " + x;
			}

			@Override
			String create(int x, int y) {
				return "hello " + x + " goodbye " + y;
			}

			@Override
			String create(int x, int y, int z) {
				return "hello " + x + " goodbye " + y + " wingus " + z;
			}
		},

		PLACEHOLDER {
			@Override
			String create(int x) {
				return MessageFormatter.format("hello {}", x).toString();
			}

			@Override
			String create(int x, int y) {
				return MessageFormatter.format("hello {} goodbye {}", x, y)
						.toString();
			}

			@Override
			String create(int x, int y, int z) {
				return MessageFormatter.arrayFormat(
						"hello {} goodbye {} wingus {}",
						new Object[] { x, y, z }).toString();
			}
		},

		STRING_FORMAT {
			@Override
			String create(int x) {
				return String.format("hello %d", x);
			}

			@Override
			String create(int x, int y) {
				return String.format("hello %d goodbye %d", x, y);
			}

			@Override
			String create(int x, int y, int z) {
				return String.format("hello %d goodbye %d wingus %d", x, y, z);
			}
		},

		STRINGFORMATTER_FORMAT {

			@Override
			String create(int x) {
				return StringFormatter.format("hello %d", x);
			}

			@Override
			String create(int x, int y) {
				return StringFormatter.format("hello %d goodbye %d", x, y);
			}

			@Override
			String create(int x, int y, int z) {
				return StringFormatter.format("hello %d goodbye %d wingus %d", x, y, z);
			}
		};

		abstract String create(int x);

		abstract String create(int x, int y);

		abstract String create(int x, int y, int z);
	}

	@Param
	private MessageCreator creator;

	public int timeOneParameter(int count) {
		int result = 0;
		for (int i = 0; i < count; ++i) {
			result ^= creator.create(i).codePointAt(0);
		}
		return result;
	}

	public int timeTwoParameter(int count) {
		int result = 0;
		for (int i = 0; i < count; ++i) {
			result ^= creator.create(i, i + 1).codePointAt(0);
		}
		return result;
	}

	public int timeThreeParameter(int count) {
		int result = 0;
		for (int i = 0; i < count; ++i) {
			result ^= creator.create(i, i + 1, i + 2).codePointAt(0);
		}
		return result;
	}
}

Benchmark results: http://goo.gl/4fZEjl