使用正则表达式从文本中删除连续重复的单词并显示新文本

Question

Hy

我有以下代码：

import java.io.*;
import java.util.ArrayList;
import java.util.Scanner;
import java.util.regex.*;

/
public  class RegexSimple4
{

     public static void main(String[] args) {

          try {
              Scanner myfis = new Scanner(new File("D:\\myfis32.txt"));
              ArrayList <String> foundaz = new ArrayList<String>();
              ArrayList <String> noduplicates = new ArrayList<String>();

              while(myfis.hasNext()) {
                  String line = myfis.nextLine();
                  String delim = " ";
                  String [] words = line.split(delim);

                  for (String s : words) {                    
                      if (!s.isEmpty() && s != null) {
                          Pattern pi = Pattern.compile("[aA-zZ]*");
                          Matcher ma = pi.matcher(s);

                          if (ma.find()) {
                              foundaz.add(s);
                          }
                      }
                  }
              }

              if(foundaz.isEmpty()) {
                  System.out.println("No words have been found");
              }

              if(!foundaz.isEmpty()) {
                  int n = foundaz.size();
                  String plus = foundaz.get(0);
                  noduplicates.add(plus);
                  for(int i=1; i<n; i++) {   
                      if ( !noduplicates.get(i-1) .equalsIgnoreCase(foundaz.get(i))) {
                          noduplicates.add(foundaz.get(i));
                      }
                  }

                  //System.out.print("Cuvantul/cuvintele \n"+i);

              }
              if(!foundaz.isEmpty()) { 
                  System.out.print("Original text \n");
                  for(String s: foundaz) {
                      System.out.println(s);
                  }
              }
              if(!noduplicates.isEmpty()) {
                  System.out.print("Remove duplicates\n");
                  for(String s: noduplicates) {
                      System.out.println(s);
                  }
              }

          } catch(Exception ex) {
              System.out.println(ex); 
          }
      }
  }

目的是从短语中删除连续的重复项。该代码仅适用于一列字符串，不适用于全长短语。

例如，我的输入应为：

布拉布拉狗猫老鼠。猫老鼠狗狗。

和输出

布拉狗猫老鼠。猫老鼠狗。

真诚的

Answer 1

首先，正则表达式[aA-zZ]*不会执行您认为的操作。这意味着“匹配零个或多个aS或字符ASCII之间的范围内A和ASCII
z（其还包括[，]，\及其它），或ZS”。因此，它也匹配空字符串。

假设您只在寻找不重复的单词，该单词仅由ASCII字母组成，不区分大小写，保留第一个单词（这意味着您不希望匹配"it's it's"或"olé olé!"），那么您可以在单个regex操作中做到这一点：

String result = subject.replaceAll("(?i)\\b([a-z]+)\\b(?:\\s+\\1\\b)+", "$1");

将会改变

Hello hello Hello there there past pastures

进入

Hello there past pastures

说明：

(?i)     # Mode: case-insensitive
\b       # Match the start of a word
([a-z]+) # Match one ASCII "word", capture it in group 1
\b       # Match the end of a word
(?:      # Start of non-capturing group:
 \s+     # Match at least one whitespace character
 \1      # Match the same word as captured before (case-insensitively)
 \b      # and make sure it ends there.
)+       # Repeat that as often as possible

看到它住在regex101.com。