java string reverse
String str = "Reverse this strings";
//for loop
for (int i = str.length() - 1; i >= 0; i--) {
System.out.print(str.charAt(i));
}
// StringBuffer for multi thread
StringBuffer sb = new StringBuffer();
sb.append(str);
System.out.print(sb.reverse().toString());
// StringBuffer for single thread
StringBuilder sb = new StringBuilder();
sb.append(str);
System.out.print(sb.reverse().toString());