java - 在java中为行之间存在的字符串编写正则表达式

Question

我的输入字符串是:

subtype=forward,level=notice,vd=root,srcip=10.100.1.121,srcport=55844,srcintf=port1,dstip=173.193.156.43,dstport=80,dstintf=port16,sessionid=1224203695,status=close
subtype=forward,level=notice,vd=root,srcip=10.100.1.121,srcport=55844,srcintf=port1,dstip=173.193.156.43,dstport=80,dstintf=port16,sessionid=1224203695,status=open 

这是我尝试过的代码:

Pattern patt = Pattern.compile("(srcip=(?:\\d+\\.)+\\d+)(?:.*)?(dstip=(?:\\d+\\.)+\\d+)(?:.*)?(status=(?=.*close.*)(?:.*)?(dstport=(\\d+))");

BufferedReader r = new BufferedReader(new FileReader("ttext.txt"));

// For each line of input, try matching in it.
String line;
while ((line = r.readLine()) != null) {
  // For each match in the line, extract and print it.
  Matcher m = patt.matcher(line);
  while (m.find()) {
    // Simplest method:

    System.out.print(" " + m.group(1) + " " );
    System.out.print(" " + m.group(2) + " " );
System.out.print(" " + m.group(3) + " " );
System.out.println(" " + m.group(4));

预期输出是:

srcip=10.100.1.121 dstip=173.193.156.43 srcport=55844 status=close dstport=80  

但这是我得到的输出:

srcip=10.100.1.121  dstip=173.193.156.43  dstip=173.193.156.43  dstport=80
srcip=10.100.1.121  dstip=173.193.156.43  dstip=173.193.156.43  dstport=80

有什么建议吗？

Answer 1

捕获组的顺序与输入中字段的顺序不对应。这是正则表达式的重新排序版本，它捕获您需要的 5 个组:

String s = "subtype=forward,level=notice,vd=root,srcip=10.100.1.121,srcport=55844,srcintf=port1,dstip=173.193.156.43,dstport=80,dstintf=port16,sessionid=1224203695,status=close";

Pattern p = Pattern.compile("(srcip=(?:\\d+\\.)+\\d+)(?:.*)?(srcport=(?:\\d+))(?:.*)?(dstip=(?:\\d+\\.)+\\d+)(?:.*)?(dstport=(?:\\d+))(?:.*)?(status=(?:.*))");
Matcher m = p.matcher(s);

if (m.find()) {
  System.out.println(m.group(1) + " " + m.group(3) + " " + m.group(2) + " " + m.group(5) + " " + m.group(4));
}

请注意，我还修复了一个未封闭的组，并使其中一个组不捕获。