Java algorithm for solving prime numbers

Number of primes in 100:

   public void A () {for              (int i = 2; I <=; i++) {                  int temp = (int) math.sqrt (i);                  I put that aqrt alone, so the speed is a little bit faster, although the change in 100 is not small, but if it is a prime number within 10000000?                  if (I <= 3) {                      System.out.println (i + "is a Prime");                  } else {for                      (int j = 2; J <= Temp; j + +) {//Put math. sqrt (i) converted to int class                          if (i% j = 0) {break                              ;                          }                          if (J >= temp) {                              System.out.println (i + "is a Prime");}}}}            

(ii) The number of primes between n-m

  public void Sushu (int n, int. m) {for              (int i = n; i < m; i++) {                  int temp = (int) math.sqrt (i);                  if (i<=3) {                      System.out.println (i);                  }                  for (int j = 2; J <= Temp; j + +) {                      if (i%j==0) {break                          ;                      }                      if (j>=temp) {                          System.out.println (i);}}              }          

Java algorithm for solving prime numbers