计算文件中特定String的出现次数 [英] counting the occurence of a particular String in a file

问题描述

以下是我所使用的代码：

Here's the code that I've worked upon:

while ((lineContents = tempFileReader.readLine()) != null)
{
            String lineByLine = lineContents.replaceAll("/\\.", System.getProperty("line.separator")); //for matching /. and replacing it by new line
            changer.write(lineByLine);
            Pattern pattern = Pattern.compile("\\r?\\n"); //Find new line
            Matcher matcher = pattern.matcher(lineByLine);
            while(matcher.find())
            {
                Pattern tagFinder = Pattern.compile("word"); //Finding the word required
                Matcher tagMatcher = tagFinder.matcher(lineByLine);
                while(tagMatcher.find())
                {
                    score++;
                }
                scoreTracker.add(score);
                    score = 0;
            }   
}

我的示例输入包含6行，其中出现 word [0,1,0,3,0,0]
所以当我打印 scoreTracker （这是 ArrayList ）我想要上面的输出。
但是，我得到 [4,4,4,4,4,4] 这是字的总出现次数，但不是逐行的。
请帮忙。

My sample input contains 6 lines, with occurences of word being [0,1,0,3,0,0] So when I print scoreTracker (which is an ArrayList) I want the above output. But instead, I get [4,4,4,4,4,4] which it the total occurence of the word, but not line by line. Kindly help.

推荐答案

lineByLine 指向整个你文件的内容。这就是你得到 [4,4,4,4,4,4] 的原因。您需要将每一行存储在另一个变量行中，然后使用 tagFinder.find（line）。
最终代码将如下所示

lineByLine points to the entire contents of your file. That is the reason you are getting [4,4,4,4,4,4]. You need to store each line in another variable line and then use tagFinder.find(line). Final code will look like this

while ((lineContents = tempFileReader.readLine()) != null)
{
    String lineByLine = lineContents.replaceAll("/\\.", System.getProperty("line.separator")); //for matching /. and replacing it by new line
    changer.write(lineByLine);
    Pattern pattern = Pattern.compile(".*\\r?\\n"); //Find new line
    Matcher matcher = pattern.matcher(lineByLine);
    while(matcher.find())
    {
        Pattern tagFinder = Pattern.compile("word"); //Finding the word required
        //matcher.group() returns the input subsequence matched by the previous match.
        Matcher tagMatcher = tagFinder.matcher(matcher.group());
        while(tagMatcher.find())
        {
            score++;
        }
        scoreTracker.add(score);
            score = 0;
    }   
}

这篇关于计算文件中特定String的出现次数的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！