Java Best Practices - Concat String

NORMAL PRACTICE

   1:  public class Main {

   2:      public static void main(String[] args) {

   3:          String text = "Hello" + " World";

   4:      }

   5:  }

BEST PRACTICE

Not Thread-safe

   1:      StringBuilder sb = new StringBuilder();

   2:      sb.append("Hello ");

   3:      sb.append("World");

Thread-Safe

   1:      StringBuffer sb = new StringBuffer();

   2:      sb.append("Hello ");

   3:      sb.append("World");