BAEL-1065 Simple performance check StringBuffer vs StringBuilder.

core-java/src/main/java/com/baeldung/string/StringBufferStringBuilder.java

@@ -0,0 +1,25 @@
+package com.baeldung.string;
+
+public class StringBufferStringBuilder {
+
+    public static void main(String[] args) {
+
+        int iterations = 10000000;
+
+        System.gc();
+        long startTime = System.currentTimeMillis();
+        StringBuffer stringBuffer = new StringBuffer("abc");
+        for (int i = 0; i < iterations; i++) {
+            stringBuffer.append("def");
+        }
+        System.out.println("Time taken by StringBuffer: " + (System.currentTimeMillis() - startTime) + "ms"); // Time taken by StringBuffer: 394ms
+
+        System.gc();
+        startTime = System.currentTimeMillis();
+        StringBuilder stringBuilder = new StringBuilder("abc");
+        for (int i = 0; i < iterations; i++) {
+            stringBuilder.append("def");
+        }
+        System.out.println("Time taken by StringBuilder: " + (System.currentTimeMillis() - startTime) + "ms"); // Time taken by StringBuilder: 129ms
+    }
+}