如何编写regex来查找.txt文件中的所有电话号码

Question

我正在尝试从.txt文件中提取所有电话号码。该文件包含一些具有不同电话号码的文本，这些文本具有不同的长度和国家代码。文件中的一个例子是

not every line has a number
6/24/21, 12:14 am - [phone] joined using this group's invite link
6/23/21, 5:09 pm - [phone] joined using this group's invite link
6/23/21, 5:09 pm - [phone]:

到目前为止，我所做的是

File file = new File("chat.txt");
Scanner content = new Scanner(file);
while(content.hasNext())
{
String line = content.nextLine();
String patternString = "(+[1-9]d{0,2}[- ]?)?[1-9]d{9}"; //pretty sure this is the issue
Pattern pattern = Pattern.compile(patternString);
Matcher matcher = pattern.matcher(line);
boolean matchFound = matcher.find(); //should return true if it finds a phone number
if(matchFound){
String phone = ; //substring the found phone number  
// output or write in a new file
}              
}

缺少的是模式(regex(和电话号码的子字符串方式。不幸的是，我找不到这样做的解决方案。我们将非常感谢你的帮助。

Answer 1

public static void main(String[] args) throws Exception {
File file = new File("chat.txt");
String patternString = "\+\d{2,3}(?: \d{3,4}){2,3}";
Pattern pattern = Pattern.compile(patternString);
try (Scanner content = new Scanner(file)) {
while (content.hasNext()) {
String line = content.nextLine();
Matcher matcher = pattern.matcher(line);
if (matcher.find()) {
System.out.println(matcher.group());
}
}
}
}

是一种方法。非捕捉组，重复。

Answer 2

要查找字符串，请使用：

if(matcher.find()){
String phone = matcher.group(1); 
// output or write in a new file
}

一个应该起作用的正则表达式示例是：

^+[1-9]{1}[0-9]{3,14}$