如何使用Java正则表达式过滤html文件内容？

Question

With java I can download a webpage into the txt file.Now I want to read values from this txt file by regular expression.The below is the small part of the real html.

<div>
   <input id="_NAME" value="/John/" />
   <input id="_LASTNAME" value="/BOND/"/>
   <input id="_Class"   value="5" />
</div>

I just want to read values according to id (_Name and _LASTNAME)? Thanks in advance

Answer 1

As long as the HTML file is usable when browsing, it should be parsable by Jsoup. Since you are only querying attributes of input element, you don't really have to worry about the structure of the resulting DOM.

Sample code, using your example of HTML, with a bunch of bad HTML tag in front:

import org.jsoup.Jsoup;
import org.jsoup.nodes.Document;
import org.jsoup.nodes.Element;
import org.jsoup.select.Elements;


public class SO27938637 {
    public static void main(String[] args) {
        Document doc = Jsoup.parse("<div><span><div><b>sdf</span>dsf<i>sdfdsfsdfds<span></div><div>\n    <input id=\"_NAME\" value=\"/John/\" />\n   <input id=\"_LASTNAME\" value=\"/BOND/\"/>\n   <input id=\"_Class\"   value=\"5\" /></div>");
        Elements inputElement = doc.select("input");

        for (Element e: inputElement) {
            System.out.println(e.attr("id") + ": " + e.attr("value"));
        }
    }
}

Output:

_NAME: /John/
_LASTNAME: /BOND/
_Class: 5