[06] Create benchmark for String::format

Nicolai Parlog · Nicolai Parlog · commit 2f42b462ce3d · 2019-05-24T17:49:52.000+02:00
diff --git a/src/main/java/org/codefx/demo/effective_java/_06_unnecessary_objects/StringFormat.java b/src/main/java/org/codefx/demo/effective_java/_06_unnecessary_objects/StringFormat.java
@@ -0,0 +1,34 @@
+package org.codefx.demo.effective_java._06_unnecessary_objects;
+
+import org.openjdk.jmh.annotations.Benchmark;
+import org.openjdk.jmh.annotations.BenchmarkMode;
+import org.openjdk.jmh.annotations.Fork;
+import org.openjdk.jmh.annotations.Measurement;
+import org.openjdk.jmh.annotations.Mode;
+import org.openjdk.jmh.annotations.OutputTimeUnit;
+import org.openjdk.jmh.annotations.Param;
+import org.openjdk.jmh.annotations.Scope;
+import org.openjdk.jmh.annotations.State;
+import org.openjdk.jmh.annotations.Warmup;
+
+import java.util.concurrent.TimeUnit;
+
+public class StringFormat extends ObjectCreationBenchmarks {
+
+	@Param({ "Motoko", "Batou" })
+	private String name = "_";
+
+	@Benchmark
+	public String format() {
+		// NOTE unnecessary object:
+		//   The JVM has to create an array for `name` and `9`
+		//   and box the latter into an `Integer`
+		return String.format("%s(Section %d)", name, 9);
+	}
+
+	@Benchmark
+	public String concatenate() {
+		return name + "(Section " + 9 + ")";
+	}
+
+}
