查找子串在父串中出现的次数JAVA

package HelloWorld;
import java.util.Scanner;

public class wang1 {

	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		String str = sc.nextLine();
		String s ="chuanzhi";
		int num = 0;
		int count = 0;
		while((num = str.indexOf(s,num))!=-1) {
			num = num+s.length();
			count++;
		}
		System.out.println(count);
	}
}

Scanner类获取输入的字符串