java常用API之查找字符串出現次數

/*
*1.先定義一個字符串，以及需要查找的字符串
	String st1="nafjfalsnafjlajnafjlkajnafjlakjfnafjlajfnafnafnafnanfanfanfnafnafnfanfanfnafn";
	String key="naf";
*2.定義一個計數器用於記錄次數
*3.判斷是否查找到,如果找到就記錄
*4.接着查找第二個位置
*5.循環
	


*/
public class FindKey//查找數組中一個字符串出現的次數

{
	public static void main(String[] args)
	{
		String st1="nafjfalsnafjlajnafjlkajnafjlakjfnafjlajfnafnafnafnanfanfanfnafnafnfanfanfnafn";
		String key1="naf";
		String key2="naf";
		int count1 = getKey1(st1 , key1);
		System.out.print("count1="+count1);
		int count2 = getKey2(st1 , key2);
		System.out.print("count2="+count2);
	}
	public static int getKey1(String st1 , String key1)
	{
		int count = 0;
		int index = 0;
		while((index = st1.indexOf(key1,index))!=-1)
		{
			index = index+key1.length();
			count++;
		}
		return count;
	}
	public static int getKey2(String st1 , String key2)
	{
		int index = 0;
		int count2 = 0;
		while((index=st1.indexOf(key2))!=-1)
		{
			st1 = st1.substring(index+key2.length());
			count2++;
		}
		return count2;
	}
		
}