Get all Images from WebPage Program | Java_问答_开发者

Get all Images from WebPage Program | Java

开发者 https://www.devze.com 2022-12-19 05:04 出处：网络

Currently I need a program that given a URL, returns a list of all the images on the webpage. ie: logo.png

相关专题：extract

Currently I need a program that given a URL, returns a list of all the images on the webpage.

ie:

logo.png gallery1.jpg test.gif

Is there any open so开发者_高级运维urce software available before I try and code something?

Language should be java. Thanks Philip

Just use a simple HTML parser, like jTidy, and then get all elements by tag name img and then collect the src attribute of each in a List<String> or maybe List<URI>.

You can obtain an InputStream of an URL using URL#openStream() and then feed it to any HTML parser you like to use. Here's a kickoff example:

InputStream input = new URL("http://www.stackoverflow.com").openStream();
Document document = new Tidy().parseDOM(input, null);
NodeList imgs = document.getElementsByTagName("img");
List<String> srcs = new ArrayList<String>();

for (int i = 0; i < imgs.getLength(); i++) {
    srcs.add(imgs.item(i).getAttributes().getNamedItem("src").getNodeValue());
}

for (String src: srcs) {
    System.out.println(src);
}

I must however admit that HtmlUnit as suggested by Bozho indeed looks better.

HtmlUnit has HtmlPage.getElementsByTagName("img"), which will probably suit you.

(read the short Get started guide to see how to obtain the correct HtmlPage object)

This is dead simple with HTML Parser (and any other decent HTML parser):

Parser parser = new Parser("http://www.yahoo.com/");
NodeList list = parser.parse(new TagNameFilter("IMG"));

for ( SimpleNodeIterator iterator = list.elements(); iterator.hasMoreNodes(); ) {
    Tag tag = (Tag) iterator.nextNode();
    System.out.println(tag.getAttribute("src"));
}

You can use wget that has a lot of options available.

Or google for java wget ...

You can parse the HTML, and collect all SRC attributes of IMG elements in a Collection. Then download each resource from each url and write it to a file. For parsing there are several HTML parsers available, Cobra is one of them.

With Open Graph tags and HTML unit, you can extract your data really easily (PageMeta is a simple POJO holding the results):

    Parser parser = new Parser(url);

    PageMeta pageMeta = new PageMeta();
    pageMeta.setUrl(url);

    NodeList meta = parser.parse(new TagNameFilter("meta"));
    for (SimpleNodeIterator iterator = meta.elements(); iterator.hasMoreNodes(); ) {
        Tag tag = (Tag) iterator.nextNode();

        if ("og:image".equals(tag.getAttribute("property"))) {
            pageMeta.setImageUrl(tag.getAttribute("content"));
        }

        if ("og:title".equals(tag.getAttribute("property"))) {
            pageMeta.setTitle(tag.getAttribute("content"));
        }

        if ("og:description".equals(tag.getAttribute("property"))) {
            pageMeta.setDescription(tag.getAttribute("content"));
        }
    }

You can simply use regular expression in Java

<html>
<body>
<p>
<img src="38220.png" alt="test" title="test" /> 
<img src="32222.png" alt="test" title="test" />
</p>
</body>
</html>

    String s ="html";  //above html content
    Pattern p = Pattern.compile("<img [^>]*src=[\\\"']([^\\\"^']*)");
    Matcher  m = p.matcher (s);
    while (m.find()) {
        String src = m.group();
        int startIndex = src.indexOf("src=") + 5;
        String srcTag = src.substring(startIndex, src.length());
        System.out.println( srcTag );
    }