Java，文本中的n个单词数

此类的目的是计算用户输入的文本中每个n字符单词的出现次数。 我认为在methodsNumber方法中存在一些错误，因为我为每个n字符单词获得228。 错误在哪里？

import java.io.BufferedReader; import java.io.IOException; import java.io.InputStreamReader; import java.util.Scanner; public class TempTest { public static void main(String[] args) { BufferedReader in = new BufferedReader(new InputStreamReader(System.in)); System.out.println("Enter the integer n"); Scanner sc = new Scanner(System.in); int n = sc.nextInt(); char[] array = { 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z', ' ' }; StringBuffer[] table = createTotalTable(n, array); System.out.println("Enter the text "); StringBuffer text = new StringBuffer(""); try { text = new StringBuffer(in.readLine()); } catch (IOException a) { System.out.println("Input-Output problem"); } StringBuffer text_formatted = format(text.toString()); System.out.println("The formatted text is \n" + text_formatted.toString() + "\n"); System.out.println("Now we print all the n-character words in alphabetic order. Press enter to proceed. "); try { in.readLine(); } catch (IOException b) { System.out.println("Input-Output problem"); } for (StringBuffer word : table) System.out.println(word.toString()); int[] occurrenceTable = createList(text_formatted, table, n); System.out.println("Now we print all the n-words contained in the text with the number of occurrences. Press enter to proceed."); try { in.readLine(); } catch (IOException c) { System.out.println("Input-Output problem"); } for (int u = 0; u < pow(27, n); u++) System.out.println(table[u].toString() + ", " + occurrenceTable[u]); } public static StringBuffer[] createTotalTable(int n, char[] a) { // this method create an array containing all the n-words in alphabetic order StringBuffer[] table = new StringBuffer[pow(27, n)]; for (int w = 0; w < pow(27, n); w++) table[w] = new StringBuffer(""); for (int h = 1; h <= n; h++) { for (int u = 0; u < pow(27, h - 1); u++) { for (int j = 0; j < 27; j++) { for (int x = pow(27, n - h + 1) * u + pow(27, n - h) * j; x < pow(27, n - h + 1) * u + pow(27, n - h) * (j + 1); x++) table[x] = table[x].append(a[j]); } } } return table; } public static int pow(int a, int b) { // the method Math.pow modified int tot = 1; for (int i = 0; i  testo.length()) System.out.println("The integer is bigger than the text's length "); else { for (int i = 0; i <= testo.length() - n; i++) { if (testo.substring(i, i + n) == parola.toString()) tot += 1; } } return tot; } public static int[] createList(StringBuffer str, StringBuffer[] tabella, int n) { // this method is aimed to create an array containing for every position // the number of occurrences of the corresponding word in the text int[] occurrenceTable = new int[pow(27, n)]; for (int i = 0; i < pow(27, n); i++) occurrenceTable[i] = occurrenceNumber(str, tabella[i], n); return occurrenceTable; } public static StringBuffer format(String s) { // this method is aimed to // eliminate from the text all non-alphabetic characters and multiple spaces s = s.toLowerCase(); StringBuffer b = new StringBuffer(); int m = s.length(); int conta_spazi = 0; StringBuffer h = new StringBuffer(s); for (int i = 0; i < m; i++) { switch (h.charAt(i)) { case 'a': break; case 'A': break; case 'b': break; case 'B': break; case 'c': break; case 'C': break; case 'd': break; case 'D': break; case 'e': break; case 'E': break; case 'f': break; case 'F': break; case 'g': break; case 'G': break; case 'h': break; case 'H': break; case 'i': break; case 'I': break; case 'j': break; case 'J': break; case 'k': break; case 'K': break; case 'l': break; case 'L': break; case 'm': break; case 'M': break; case 'n': break; case 'N': break; case 'o': break; case 'O': break; case 'p': break; case 'P': break; case 'q': break; case 'Q': break; case 'r': break; case 'R': break; case 's': break; case 'S': break; case 't': break; case 'T': break; case 'u': break; case 'U': break; case 'v': break; case 'V': break; case 'w': break; case 'W': break; case 'x': break; case 'X': break; case 'y': break; case 'Y': break; case 'z': break; case 'Z': break; default: h.setCharAt(i, ' '); } } for (int i = 0; i < m; i++) { if (h.charAt(i) == ' ') conta_spazi++; else conta_spazi = 0; if (conta_spazi <= 1) b = b.append(h.charAt(i)); } return b; } } 

Answer 1

要比较2个字符串，您需要调用equals方法而不是==

你应该替换：

  if(testo.substring(i,i+n) == parola.toString()) 

同

 if(testo.substring(i,i+n).equals(parola.toString())) 

Answer 2

我无法弄清楚你正在实施的逻辑。 但是，您可以通过更简单的方法找到计数：

  // extract n-char words and add them to a list ArrayList arr = new ArrayList(); Pattern pattern = Pattern.compile("(^|\\s)\\w{" + n + "}(\\s|$)"); Matcher matcher = pattern.matcher(text_formatted); while (matcher.find()) { int k = 0; arr.add(matcher.group(k++).trim()); } // sort the list Collections.sort(arr); // find the count and print String prev = ""; int count = 1; for (int i = 0; i < arr.size(); i++) { if (prev.equals(arr.get(i))) { count++; } else { count = 1; System.out.print(arr.get(i)+" : "); } if(i 

希望这会有所帮助。