使用 java 扫描仪解析文本文件
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parsing a text file using a java scanner
提问by Programatt
I am trying to create a method that parses a text file and returns a string that is the url after the colon. The text file looks as follow (it is for a bot):
我正在尝试创建一个方法来解析文本文件并返回一个字符串，该字符串是冒号后的 url。文本文件如下所示（用于机器人）：
keyword:url
keyword,keyword:url
关键字：url
关键字，关键字：url
so each line consists of a keyword and a url, or multiple keywords and a url.
所以每一行由一个关键字和一个 url 组成，或者多个关键字和一个 url。
could anyone give me a bit of direction as to how to do this? Thank you.
谁能给我一些关于如何做到这一点的方向？谢谢你。
I believe I need to use a scanner but couldn't find anything on anyone wanting to do anything similar to me.
我相信我需要使用扫描仪，但在任何想要做与我类似的事情的人身上找不到任何东西。
Thank you.
谢谢你。
edit: my attempt using suggestions below. doesn't quite work. Any help would be appreciated.
编辑：我尝试使用以下建议。不太工作。任何帮助，将不胜感激。
public static void main(String[] args) throws IOException {
String sCurrentLine = "";
String key = "hello";
BufferedReader reader = new BufferedReader(
new FileReader(("sites.txt")));
Scanner s = new Scanner(sCurrentLine);
while ((sCurrentLine = reader.readLine()) != null) {
System.out.println(sCurrentLine);
if(sCurrentLine.contains(key)){
System.out.println(s.findInLine("http"));
}
}
}
output:
输出：
hello,there:http://www.facebook.com
null
whats,up:http:/google.com
sites.txt:
hello,there:http://www.facebook.com
whats,up:http:/google.com
回答by Ben Dale
回答by slanecek
Use BufferedReader, for text parsing you can use regular expresions.
使用 BufferedReader，对于文本解析，您可以使用正则表达式。
回答by PythaLye
You should use the split method:
您应该使用 split 方法：
String strCollection[] = yourScannedStr.Split(":", 2);
String extractedUrl = strCollection[1];
回答by Boris the Spider
You should read the file line by line with a BufferedReaderas you are doing, I would the recommend parsing the file using regex.
您应该在执行时使用 a 逐行阅读文件BufferedReader，我建议使用正则表达式解析文件。
The pattern
图案
(?<=:)http://[^\s]++
Will do the trick, this pattern says:
会成功，这个模式说：
- http://
- followed by any number of non-space characters (more than one)
[^\\s]++ - and preceded by a colon
(?<=:)
- http://
- 后跟任意数量的非空格字符（多于一个）
[^\\s]++ - 并以冒号开头
(?<=:)
Here is a simple example using a Stringto proxy your file:
这是一个使用 aString来代理您的文件的简单示例：
public static void main(String[] args) throws Exception {
final String file = "hello,there:http://www.facebook.com\n"
+ "whats,up:http://google.com";
final Pattern pattern = Pattern.compile("(?<=:)http://[^\s]++");
final Matcher m = pattern.matcher("");
try (final BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(new ByteArrayInputStream(file.getBytes("UTF-8"))))) {
String line;
while ((line = bufferedReader.readLine()) != null) {
m.reset(line);
while (m.find()) {
System.out.println(m.group());
}
}
}
}
Output:
输出：
http://www.facebook.com
http://google.com
