Jsoup，从网站提取链接，图像.运行时异常 [英] Jsoup, extract links, images, from website. Exception on runtime

问题描述

我刚刚开始使用Jsoup，所以请遵循他们在该网站上的教程.我认为这段代码应该可以正常工作，但是当我在netbeans上运行它时，我会遇到错误.

I am just starting to play around with Jsoup, so followed the tutorial they had on there website. This code i assume should work fine but when i am running it on netbeans I am coming across errors.

这是我正在使用的代码:

This is the code i am using:

`

/**
 *
 * @author Slabs One
 */
public class ParseWebpage {

/**
 * @param args the command line arguments
 */
public static void main(String[] args) throws IOException {
    Validate.isTrue(args.length == 1, "http://www.gumtree.com.au/");
    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;
}

}

`

这段代码应该不会有任何问题，但是在运行时我会收到此错误:

There shouldnt be any problems with this code, but on runtime i get this error:

    Exception in thread "main" java.lang.IllegalArgumentException: http://www.gumtree.com.au/
at org.jsoup.helper.Validate.isTrue(Validate.java:45)
at parsewebpage.ParseWebpage.main(ParseWebpage.java:25)

任何对为什么不能正常工作的见解将不胜感激

Any insight to why this is not working would be greatly appreciated

推荐答案

要在Netbeans中传递命令行参数，您必须执行以下操作.

To pass command line arguments in Netbeans, You have to do the following.

• 右键单击项目，然后单击属性
• 在侧窗格中选择 Run
• 使用浏览对话框选择您的主类(ParseWebpage)
• 输入参数(URL)
• 单击确定

• Right-click the project and click properties
• Choose Run in the side pane
• Choose your Main class (ParseWebpage) using Browse dialog
• Input the Arguments (URL)
• Click ok

现在，如果您运行Main类(ParseWebpage)，则运行时参数将在NetBeans IDE中传递

Now, if you run the Main class (ParseWebpage), the run time argument will be passed in NetBeans IDE

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