java - java中如何统计tax中某个关键字出现了多少次？

Question

问题一:

我正在尝试计算关键字的频率，我的代码有效，但它也计算在内那些也包含关键字的词(例如，如果我搜索“count”，“account”之类的词也会被计算在内。)有人知道如何解决这个问题吗？

问题二:

我还想计算文本中唯一单词的数量(这意味着我只计算重复单词一次)。我也不知道如何实现这一目标。我的代码只给出总字数。

这是我的代码:

import java.util.Scanner;


public class Text_minining {

/**
 * @param args
 */
public static void main(String[] args) {

    //Prompt the user for the search word
    System.out.print("enter a search word: ");
    //Get the user's search word input
    Scanner keywordScanner = new Scanner(System.in);
    String keyword = keywordScanner.nextLine();
    keyword = keyword.toLowerCase();

    //Prompt the user for the text
    System.out.println("Enter a string of words (words separated by single spaces or tabs): ");
    //Get the user's string input
    Scanner userInputScanner = new Scanner(System.in);
    String userInput = userInputScanner.nextLine();
    userInput = userInput.toLowerCase();

    int keywordCount = 0, wordCount = 0;
    int lastIndex = 0;

    while(lastIndex != -1){
        lastIndex = userInput.indexOf(keyword,lastIndex);
        if(lastIndex != -1){
            keywordCount ++;
            lastIndex = keyword.length() + lastIndex;
        }
    }

    boolean wasSpace=true;
    for (int i = 0; i < userInput.length(); i++) 
    {
        if (userInput.charAt(i) == ' ') {
            wasSpace=true;
        }
        else{
            if(wasSpace == true) wordCount++;
            wasSpace = false;
            }
    }

    //Print the results to the screen
    System.out.println("-------");
    System.out.println("Good, \"" + keyword + "\"appears in the text and the word count is " + keywordCount);
    System.out.println("The total number of unique words in the text is " + wordCount);


    System.exit(0);
}
    }

Answer 1

首先:userInput.split(keyword).length - 1 可以解决问题。我们使用正则表达式。

第二个:

Set<String> uniqueWords = new HashSet<String>();
for (String word : userInput.split(" ")) {
   uniqueWords.add(word);
}
System.out.println("Unique words count " + uniqueWords.size());