Find Duplicate Character using Java

package com.java.basicprograms;

public class DuplicateChar {

public static void main(String[] args) {
String str = "maheshbabu";
int length = str.length();
char[] ch = str.toCharArray();
for (int i = 0; i < length; i++) {
for (int j = i + 1; j < length; j++) {
if (ch[i] == ch[j]) {
System.out.println("Duplicate characters are:    " + ch[j]);
break;
}
}
}
}

}