Java 一个字符串在另一个字符串中出现的次数

package com.string.to;

public class Four {
	public static void main(String args[]){
		String t="a";
		String s="advancea";
		System.out.println(new Four().sort(t,s));
	}
	public int sort(String t,String s){
		int count=0;
		String[] k=s.split(t);
		if(s.lastIndexOf(t)==(s.length()-t.length()))
			count=k.length;
		else
			count=k.length-1;
		if(count==0)
			System.out.println("t do not founded in s");
		else
			return count;
		return -1;
	}

}