java - 如何用正则表达式提取源IP地址和信息？

Question

我想用正则表达式提取源IP地址和信息。

这是文本文件中的示例，

"No.","Time","Source","Destination","Protocol","Length","Info","SrcPort","Dest.port","Response time","Frequency","delta"
"","2007-11-13 18:10:53.940873","127.0.0.1","127.0.0.1","HTTP","162","GET /scripts/..%25%35%63../winnt/system32/cmd.exe?/c+dir HTTP/1.0 ","43974","80","0.000000","","0.000000"
             I want to extract...    ^ this    ... and ...                     ^ this info

它可以包含数千行。我只想从每一行中提取源 IP 地址和信息。

预期输出是，

127.0.0.1 GET /scripts/..%25%35%63../winnt/system32/cmd.exe?/c+dir HTTP/1.0

Answer 1

如果您想纯粹使用正则表达式来执行此操作:

public static void main(String[] args)
{   
    String s = "No.\",\"Time\",\"Source\",\"Destination\",\"Protocol\",\"Length\",\"Info\",\"SrcPort\",\"Dest.port\",\"Response time\",\"Frequency\",\"delta\",\"2007-11-13 18:10:53.940873\",\"127.0.0.1\",\"127.0.0.1\",\"HTTP\",\"162\",\"GET /scripts/..%25%35%63../winnt/system32/cmd.exe?/c+dir HTTP/1.0 \",\"43974\",\"80\",\"0.000000\",\"\",\"0.000000";
    Matcher m = Pattern.compile("(?m)(?<IP>\(\\d){3}\\.(\\d\\.){2}\\d\).*?(?<METHOD>GET|POST|PUT|DELETE)(?<URI>.*?(?<HTTPVERSION>HTTP\\/\\d(\\.\\d)?))").matcher(s);
    m.find();
    System.out.println("Result " + m.group("IP") + " " + m.group("METHOD") + " " + m.group("URI") + " " + m.group("HTTPVERSION"));
}

附注命名组从 Java 7 开始工作。我使用命名组只是为了方便，没有命名组也可以获得相同的结果。无论如何，我不会严重依赖正则表达式来完成此类任务。如果你想添加哪怕一条规则、条件等，正则表达式的增长速度非常快。正则表达式不是一根魔杖。请谨慎使用。