CODE EXAMPLE FOR JAVA

how to find prime numbers in java

public class PrimeExample2{    

  static void checkPrime(int n){  
    int i,m=0,flag=0;      
    m=n/2;      
    if(n==0||n==1){  
     System.out.println(n+" is not prime number");      
    }else{  
       for(i=2;i<=m;i++){      
        if(n%i==0){      
         System.out.println(n+" is not prime number");      
         flag=1;      
         break;      
      }      
     }      
     if(flag==0)  { System.out.println(n+" is prime number"); }  
    }//end of else  
  }  
 public static void main(String args[]){    
  checkPrime(1);  
  checkPrime(3);  
  checkPrime(17);  
  checkPrime(20);  
}    
}