String Buffer vs StringBuilder vs Concatination Operator +

Run this code ... you will realize using concatination operator is better than stringBuilder
Most of us ( including me ) had the idea that StringBuilder will be fast

                long now = System.currentTimeMillis();
                for (int i=0; i<10000000; i++) {
                    String str = "one; two " +
                        ";three four; five; six" +
                        "seven eight nine ten";
                }
                long then = System.currentTimeMillis();
                System.out.println("+ " + Long.toString(then - now));

                now = System.currentTimeMillis();
                for (int i=0; i<10000000; i++) {
                    StringBuilder sb = new StringBuilder(200);
                    sb.append("one; two ");
                    sb.append(
                     ";three four; five; six");
                    sb.append(
                     "seven eight nine ten");
                    String str = sb.toString();
                }
                then = System.currentTimeMillis();
                System.out.println("StringBuilder " + Long.toString(then - now));
           
         now = System.currentTimeMillis();
        for (int i=0; i<10000000; i++) {
             StringBuffer sb = new StringBuffer(200);
             sb.append("one; two ");
             sb.append(
              ";three four; five; six");
             sb.append(
              "seven eight nine ten");
             String str = sb.toString();
         }
         then = System.currentTimeMillis();
         System.out.println("String Buffer " + Long.toString(then - now));  

Output on my PC was ...

+ 32
StringBuilder  9031
String Buffer  12125