Java:如何使用 JSoup 读取该网站的数据？我如何找到标签和类之类的东西？

Question

我正在尝试从该网站( http://pokesniper.boosting-service.de/ )的每一列中读取口袋妖怪名称和坐标，以开发显示此类数据的桌面应用程序。我从来没有用 HTML 编程过。

这对我来说是如此新奇和复杂，我搜索了很多教程，但他们从未解释如何获取元素 ID、标签等来指定他们想要打印的数据。我知道网页上的检查元素，但我只是不知道要寻找什么，所以如果您可以帮助我制作一个打印该数据的示例，我可以分析该数据以了解如何使用 JSoup不胜感激。

或者，如果您很慷慨，您也可以解释一下您是如何获得标签和 ID 的，以便我可以更快地学习并了解以供将来引用。

Answer 1

Jsoup, a HTML parser, its “jquery-like” and “regex” selector syntax is very easy to use and flexible enough to get whatever you want. Below are three examples to show you how to use Jsoup to get links, images, page title and “div” element content from a HTML page.

基本上，只有在需要进行大量编辑时才应使用 jsoup。就像如果你想给很多人提供ID <input>标签或者如果您想从互联网网页读取数据。

这个来自 jsoup 官方网站的示例应该会有所帮助。
https://jsoup.org/cookbook/extracting-data/example-list-links

This example program demonstrates how to fetch a page from a URL; extract links, images, and other pointers; and examine their URLs and text.

Specify the URL to fetch as the program's sole argument.

package org.jsoup.examples;

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

import java.io.IOException;

/**
 * Example program to list links from a URL.
 */
public class ListLinks {
    public static void main(String[] args) throws IOException {
        Validate.isTrue(args.length == 1, "usage: supply url to fetch");
        String url = args[0];
        print("Fetching %s...", url);

        Document doc = Jsoup.connect(url).get();
        Elements links = doc.select("a[href]");
        Elements media = doc.select("[src]");
        Elements imports = doc.select("link[href]");

        print("\nMedia: (%d)", media.size());
        for (Element src : media) {
            if (src.tagName().equals("img"))
                print(" * %s: <%s> %sx%s (%s)",
                        src.tagName(), src.attr("abs:src"), src.attr("width"), src.attr("height"),
                        trim(src.attr("alt"), 20));
            else
                print(" * %s: <%s>", src.tagName(), src.attr("abs:src"));
        }

        print("\nImports: (%d)", imports.size());
        for (Element link : imports) {
            print(" * %s <%s> (%s)", link.tagName(),link.attr("abs:href"), link.attr("rel"));
        }

        print("\nLinks: (%d)", links.size());
        for (Element link : links) {
            print(" * a: <%s>  (%s)", link.attr("abs:href"), trim(link.text(), 35));
        }
    }

    private static void print(String msg, Object... args) {
        System.out.println(String.format(msg, args));
    }

    private static String trim(String s, int width) {
        if (s.length() > width)
            return s.substring(0, width-1) + ".";
        else
            return s;
    }
}

输出

Fetching http://news.ycombinator.com/...

Media: (38)
 * img: <http://ycombinator.com/images/y18.gif> 18x18 ()
 * img: <http://ycombinator.com/images/s.gif> 10x1 ()
 * img: <http://ycombinator.com/images/grayarrow.gif> x ()
 * img: <http://ycombinator.com/images/s.gif> 0x10 ()
 * script: <http://www.co2stats.com/propres.php?s=1138>
 * img: <http://ycombinator.com/images/s.gif> 15x1 ()
 * img: <http://ycombinator.com/images/hnsearch.png> x ()
 * img: <http://ycombinator.com/images/s.gif> 25x1 ()
 * img: <http://mixpanel.com/site_media/images/mixpanel_partner_logo_borderless.gif> x (Analytics by Mixpan.)

Imports: (2)
 * link <http://ycombinator.com/news.css> (stylesheet)
 * link <http://ycombinator.com/favicon.ico> (shortcut icon)

Links: (141)
 * a: <http://ycombinator.com>  ()
 * a: <http://news.ycombinator.com/news>  (Hacker News)
 * a: <http://news.ycombinator.com/newest>  (new)
 * a: <http://news.ycombinator.com/newcomments>  (comments)
 * a: <http://news.ycombinator.com/leaders>  (leaders)
 * a: <http://news.ycombinator.com/jobs>  (jobs)
 * a: <http://news.ycombinator.com/submit>  (submit)
 * a: <http://news.ycombinator.com/x?fnid=JKhQjfU7gW>  (login)
 * a: <http://news.ycombinator.com/vote?for=1094578&dir=up&whence=%6e%65%77%73>  ()
 * a: <http://www.readwriteweb.com/archives/facebook_gets_faster_debuts_homegrown_php_compiler.php?utm_source=feedburner&utm_medium=feed&utm_campaign=Feed%3A+readwriteweb+%28ReadWriteWeb%29&utm_content=Twitter>  (Facebook speeds up PHP)
 * a: <http://news.ycombinator.com/user?id=mcxx>  (mcxx)
 * a: <http://news.ycombinator.com/item?id=1094578>  (9 comments)
 * a: <http://news.ycombinator.com/vote?for=1094649&dir=up&whence=%6e%65%77%73>  ()
 * a: <http://groups.google.com/group/django-developers/msg/a65fbbc8effcd914>  ("Tough. Django produces XHTML.")
 * a: <http://news.ycombinator.com/user?id=andybak>  (andybak)
 * a: <http://news.ycombinator.com/item?id=1094649>  (3 comments)
 * a: <http://news.ycombinator.com/vote?for=1093927&dir=up&whence=%6e%65%77%73>  ()
 * a: <http://news.ycombinator.com/x?fnid=p2sdPLE7Ce>  (More)
 * a: <http://news.ycombinator.com/lists>  (Lists)
 * a: <http://news.ycombinator.com/rss>  (RSS)
 * a: <http://ycombinator.com/bookmarklet.html>  (Bookmarklet)
 * a: <http://ycombinator.com/newsguidelines.html>  (Guidelines)
 * a: <http://ycombinator.com/newsfaq.html>  (FAQ)
 * a: <http://ycombinator.com/newsnews.html>  (News News)
 * a: <http://news.ycombinator.com/item?id=363>  (Feature Requests)
 * a: <http://ycombinator.com>  (Y Combinator)
 * a: <http://ycombinator.com/w2010.html>  (Apply)
 * a: <http://ycombinator.com/lib.html>  (Library)
 * a: <http://www.webmynd.com/html/hackernews.html>  ()
 * a: <http://mixpanel.com/?from=yc>  ()