获取指定字符串出现的次数

java中，如何获取指定字符串在另一个字符串中出现的次数呢？

例如，获取keyword在srcText中出现的次数？

方式一：

/**
	 * 
	 * The number of occurrences of find keyword in srcText
	 * 
	 * @param srcText
	 * @param keyword
	 * @return
	 */
	public static int findStr1(String srcText, String keyword) {
		int count = 0;
		int leng = srcText.length();
		int j = 0;
		for (int i = 0; i < leng; i++) {
			if (srcText.charAt(i) == keyword.charAt(j)) {
				j++;
				if (j == keyword.length()) {
					count++;
					j = 0;
				}
			} else {
				i = i - j;// should rollback when not match
				j = 0;
			}
		}

		return count;
	}

 

方式二：

public static int findStr2(String srcText, String keyword) {
		int count = 0;
		Pattern p = Pattern.compile(keyword);
		Matcher m = p.matcher(srcText);
		while (m.find()) {
			count++;
		}
		return count;
	}

 

方式三：

public static int findStr3(String srcText, String keyword) {
		return findStr(srcText, keyword, 0);
	}

	public static int findStr(String srcText, String keyWord, int pos) {
		int i, j, k = 0;
		i = pos;
		j = 0;
		while (i < srcText.length() && j < keyWord.length()) {
			if (srcText.charAt(i) == keyWord.charAt(j)) {
				++i;
				++j;
				if (j == keyWord.length()) {
					k = k + 1;// k++
					j = 0;
				}
			} else {
				i = i - j + 1;
				j = 0;
			}
		}
		return k;
	}

 

 

评论

3 楼 hw1287789687 2014-05-31  

lsqiang_1 写道

findStr1("../public", "../") = 1
findStr2("../public", "../") = 3
findStr3("../public", "../") = 1

跟你的测试结果不同.
System.out.println(findStr2("../public", "../")); 返回1

2 楼 lsqiang_1 2014-05-29  

findStr1("../public", "../") = 1
findStr2("../public", "../") = 3
findStr3("../public", "../") = 1

1 楼 lsqiang_1 2014-05-29  

href="../public