[06] Create benchmark for String::replace and replaceAll

Nicolai Parlog · Nicolai Parlog · commit 7ebc62014777 · 2019-05-25T08:21:13.000+02:00
diff --git a/src/main/java/org/codefx/demo/effective_java/_06_unnecessary_objects/StringReplace.java b/src/main/java/org/codefx/demo/effective_java/_06_unnecessary_objects/StringReplace.java
@@ -0,0 +1,24 @@
+package org.codefx.demo.effective_java._06_unnecessary_objects;
+
+import org.openjdk.jmh.annotations.Benchmark;
+import org.openjdk.jmh.annotations.Param;
+
+public class StringReplace extends ObjectCreationBenchmarks {
+
+	@Param({ "foobar", "foo:bar", "foo::bar" })
+	private String string = "foobar";
+
+	@Benchmark
+	public String replaceAll() {
+		// NOTE unnecessary object:
+		//   `replaceAll` accepts a regex and hence has to compile it into a pattern
+		return string.replaceAll(":", " ");
+	}
+
+	@Benchmark
+	public String replace() {
+		// use `replace` instead if you don't need to replace a regex
+		return string.replace(":", " ");
+	}
+
+}
diff --git a/src/main/java/org/codefx/demo/effective_java/_06_unnecessary_objects/StringSplit.java b/src/main/java/org/codefx/demo/effective_java/_06_unnecessary_objects/StringSplit.java
@@ -14,7 +14,7 @@ public class StringSplit extends ObjectCreationBenchmarks {
 	public String[] singleColonSplit() {
 		// NOTE unnecessary object:
 		//   For a single-character, `split` employs an optimization
-		//   and does not create a reg ex pattern
+		//   and does not create a regex pattern
 		return string.split(":");
 	}
 
@@ -41,7 +41,7 @@ public String[] singleColonCode() {
 	@Benchmark
 	public String[] doubleColonSplit() {
 		// NOTE unnecessary object:
-		//   Beyond a single character, `split` will create a create a reg ex pattern,
+		//   Beyond a single character, `split` will create a create a regex pattern,
 		//   which makes it rather slow
 		return string.split("::");
 	}
