public static void main(String[] args){
byte[] arr = {50, 48, 48, 48};
String str = new String(arr);
int i = Integer.valueOf(str);
System.out.println(i); //2000
int x=0;
x |= ((arr[0]-'0') << 24);
x |= ((arr[1]-'0') << 16);
x |= ((arr[2]-'0') << 8);
x |= ((arr[3]-'0') << 0);
System.out.println(x); //33554432
}