需要正则表达式来检索字符 < 和 > 之间的异常消息中的电子邮件 ID

Question

Need help on Regular Expression to retrieve Email IDs in Error Stack which is like "Some Text some text line break and so on".

Tried using some suggestions provided in Stack overflow. But most of them prints just the error

Below are some of the options which I tried out,

Matcher m = Pattern.compile("\\<([^>]+)\\)").matcher(e.getMessage());
while(m.find())
{
    System.out.println(m.group(1));
}
System.out.println(e.getMessage().split("<(<^>>+)>"));

exception.getMessage().split("\\[([^]]+)\\]")
exception.getMessage().split("\\<\"(.*?)\"\\>")
exception.getMessage().split("<(<^>>+)>")

Actual Resulting String array contains only one value and prints the entire stack as below,

Failed messages: javax.mail.SendFailedException: Invalid Addresses;
  nested exception is:
    com.sun.mail.smtp.SMTPAddressFailedException: 550 5.0.0 <abc@def.com>... User unknown
;
  nested exception is:
    com.sun.mail.smtp.SMTPAddressFailedException: 550 5.0.0 <def@ghi.com>... User unknown
;

PS: There is no \\ in the email id. Stack overflow did not accept the character followed by <. So added escape character before that.

Answer 1

This should do what you want, albeit with the assumption that there will only ever be one per message.

public class someClass {
    private static final Pattern idPattern = Pattern.compile("<.*>");

    public static void main(String[] args) {
        doStuff();
    }

    public static void doStuff(){
        try{
            throwNPE();
        } catch (NullPointerException ex){
            String message = ex.getMessage();
            if(idPattern.matcher(message).matches()){
                System.out.println(getId(message));
            }
        }
    }

    public static String getId(String message){
        String[] messageParts = message.split("<|>");
        if(messageParts.length > 1){
            return messageParts[1];
        }else{
            throw new IllegalArgumentException();
        }
    }

    public static void throwNPE(){
        throw new NullPointerException("<123>");
    }
}

You only really need doStuff() and getId(String) for your example (and you can drop the static), however wanted to provide a working example.

Any explanations necessary, please ask. Good luck!

Answer 2

这根据接受的答案正常工作， 正则表达式提取方括号之间的文本

Pattern.compile("\\<(.*?)\\>").matcher(e.getMessage());