To check a missing element in array

public String checkMissing(String data1[], String data2[])
{
String search = null;
int i =0;
while(i {
for(int j=0;j {
int flag = Arrays.binarySearch(data1,data2[j]);
if(flag < 0)
{
search = data2[j];
break;
}

}
i++;
}
return search;
}