Question

我需要读取某个逗号的文件，例如; String s=hii,lol,wow,and,finally

需要输出为hii,lol,wow,and 不要让最后一个逗号后跟字符因为我的代码正在读取最后一个逗号字符串示例：我将代码输出为：finally 以下是我的代码请指导我

File file =new File("C:/Users/xyz.txt");

FileInputStream inputStream = new FileInputStream(file);

String filke = IOUtils.toString(inputStream);

String[] pieces = filke.split("(?=,)");

String answer = Arrays.stream(pieces).skip(pieces.length - 1).collect(Collectors.joining());

String www=answer.substring(1);

System.out.format("Answer = \"%s\"%n", www);

Answer 1

您不一定需要使用正则表达式。只需获取最后','的索引并从0获取子字符串到该索引：

String answer = "hii,lol,wow,and,finally";
String www = answer.substring(0, answer.lastIndexOf(','));
System.out.println(www); // prints hii,lol,wow,and

Answer 2

Java中的

lastIndexOf(String str)有一个名为String s = "hii,lol,wow,and,finally";的方法。这对你来说可能会派上用场。假设您的输入为String 您可以执行String s = "hii,lol,wow,and,finally"; s = s.substring(0, s.lastIndexOf(","));操作，例如：

hii,lol,wow,and

这会为您提供输出：<table th:object="${showbudata}"> <thead> <tr> <th> Date </th> <th> Status </th> <th> HostName </th> <th> Implement Version</th> </tr> </thead> <tbody> <tr th:each="t: ${showbudata}" th:if="${server.host == t.host}"> <td th:text="${t.date}" /> <td th:text="${t.Status}" /> <td th:text="${t.host}" /> <td th:text="${t.version}" /> </tr> </tbody> </table>

Answer 3

如果您想使用java 8流为您执行此操作，可以尝试过滤？

cd electricity_profiles.git
git push --mirror https://github.com/oliversheridanmethven/electricity_profiles.git

这将打印String answer = Arrays.stream(pieces).filter(p -> !Objects.equals(p, pieces[pieces.length-1])).collect(Collectors.joining());

Answer 4

要严格正则表达式，您可以使用Pattern.compile和Matcher

Pattern.compile("\w+(?=,)");
Matcher matcher = pattern.matcher(filke);
while (matcher.find()) {
   System.out.println(matcher.group(1) + ","); // regex not good enough, maybe someone can edit it to include , (comma)
}

将匹配hii, lol, wow, and, 请参阅此处的正则表达式示例https://regex101.com/r/1iZDjg/1

如何用java读取字符串到某些逗号

4 个答案: