求指定整数以内所有的素数

import java.lang.Math;

public class PrimeNumber {
	
	public static void main(String[] args) {
		int number = 100;
		PrimeNumber p = new PrimeNumber();
		try {
			boolean[] primeNumber = p.getPrimeNumber(number);
			for (int i = 0; i < primeNumber.length; i++) {
				if(!primeNumber[i]) {
					System.out.println(i);
				}
			}
		} catch (Exception e) {
			e.printStackTrace();
		}
	}
	
	public boolean[] getPrimeNumber(int number) throws Exception {
		if(number < 1) {
			throw new Exception("所求数值不符合要求");
		}
		boolean[] container = new boolean[number+1];
		container[0] = true;
		container[1] = true;
		for(int i = 2; i <= number; i++) {
			if(!container[i])
			{
				//如果是2则不需要判断是否为素数
				if(i == 2 || i==3 || i==5 || i==7) {
					for(int j = 2; j <= number/i; j++) {
						int hole = i*j;
						container[hole] = true;
					}
				}
				else {
					int sqrt = (int)Math.sqrt(i);
					for(int j = 2; j <= sqrt; j++) {
						if(i%j == 0) {
							container[i] = true;
							break;
						}
					}
					for(int j = 2;; j++) {
						if(i*j > number) {
							break;
						}
						container[i*j] = true;
					}
				}
			}
		}
		return container;
	}
}