Question

我有一个包含多行的文本文件

类别：您遇到的问题类型
描述：问题概述
如何解决：修复问题的方法（有马车有时返回）
相关链接：其他资源

**我的清单中没有数字;这是我能想到让它更整洁的唯一方式...... *

我一直试图让我的代码识别“如何修复：”和“相关链接”之间的所有信息，当它有多行时。我从研究中得知，我必须使用（？s）或Pattern.DOTALL，但它们似乎都不起作用。我对Regex很新，所以我期待的是一些基本的东西。这是我的代码：

String fileName = System.getProperty("user.home") + "/Desktop/Test.txt";
                try {
                    FileReader fr = new FileReader(fileName);
                    BufferedReader br = new BufferedReader(fr);
                    sc1 = new Scanner(br);
                    String findingRegex = "(Description:.*)";
                    String recommRegex = "(?<=How To Fix:)(.*)(?=Related Links)";//regex I'm trying to use
                    Pattern pFinding = Pattern.compile(findingRegex);
                    Pattern pRecomm = Pattern.compile(recommRegex, Pattern.DOTALL);
                    while (sc1.hasNextLine()) {
                        String clean = sc1.nextLine().trim();
                        String clean2 = clean.replaceAll("\\\\x\\p{XDigit}{2}", "");
                        Matcher mFinding = pFinding.matcher(clean2);
                        Matcher mRecomm = pRecomm.matcher(clean2);
                        while (mFinding.find()) {                        
                            System.out.println(mFinding);
                        }
                        while (mRecomm.find()){
                            System.out.println(mRecomm); //nothing prints?
                        }
                    }
                    br.close();
                    fr.close();
                    System.out.println("The following data was imported: ");
                    try {
                        tbl.displayAll();
                    } catch (NullPointerException npe) {
                        System.out.println("You have no data.");
                    }
                } catch (FileNotFoundException fnfe) {
                    System.out.println("File named Test.txt was not located on your desktop. Program Terminated.");
                    System.exit(0);
                } catch (IOException ioe) {
                    System.out.println("The import operation failed. Program Terminated");
                    System.exit(0);
                } finally {
                    sc1.close();
                }

最后，我在这里测试了我的Regex，它按预期工作了吗？ enter image description here

我的解决方案：

String findingRegex = "(?<=Description:)(.*)(?=How To Fix)";
String recommRegex = "(?<=How To Fix:)(.*)(?=Related Links)";
Pattern pFinding = Pattern.compile(findingRegex, Pattern.DOTALL);
Pattern pRecomm = Pattern.compile(recommRegex, Pattern.DOTALL);

StringBuilder sb = new StringBuilder();
String line = br.readLine();

while (line != null){
  sb.append(line);
  sb.append(System.lineSeparator());
  line = br.readLine();
  }  
String newFile = sb.toString();
Matcher mFinding = pFinding.matcher(newFile);
Matcher mRecomm = pRecomm.matcher(newFile);
while (mFinding.find()) {                        
  System.out.println(mFinding);                            
  }
while (mRecomm.find()){
  System.out.println(mRecomm);
  }

Answer 1

下面：

String clean = sc1.nextLine().trim();

您正在逐行打破输入。但是你要尝试匹配多条线。没有多行可供匹配，因为您只保留了一行。

您可以先将整个文件读入内存，然后再与之匹配。或者你可以做类似

的事情

StringBuilder sb = new StringBuilder();
int state = 0;
while (sc1.hasNextLine()) {
  String line = sc1.nextLine();
  if (line.contains("How To Fix:")) {
    state = 1;
  }
  if (state == 1) {
    sb.append(line);
  }
  if (line.contains("Related Links:")) {
    state = 0;
  }
}

（如果每个文件需要匹配多次，则需要修改此项。）

Java中的正则表达式与文本文件中的任何内容都不匹配

1 个答案: