import org.jsoup.nodes.XmlDeclaration; //导入依赖的package包/类
@Test
public void testParseDeclarationAttributes() {
    String xml = "<?xml version='1' encoding='UTF-8' something='else'?><val>One</val>";
    Document doc = Jsoup.parse(xml, "", Parser.xmlParser());
    XmlDeclaration decl = (XmlDeclaration) doc.childNode(0);
    assertEquals("1", decl.attr("version"));
    assertEquals("UTF-8", decl.attr("encoding"));
    assertEquals("else", decl.attr("something"));
    assertEquals("version=\"1\" encoding=\"UTF-8\" something=\"else\"", decl.getWholeDeclaration());
    assertEquals("<?xml version=\"1\" encoding=\"UTF-8\" something=\"else\"?>", decl.outerHtml());
}
 

import org.jsoup.nodes.XmlDeclaration; //导入依赖的package包/类
@Override
public boolean matches(Element root, Element element) {
      	List<Node> family = element.childNodes();
          for (Node n : family) {
              if (!(n instanceof Comment || n instanceof XmlDeclaration || n instanceof DocumentType)) return false;
          }
      	return true;
}
 

import org.jsoup.nodes.XmlDeclaration; //导入依赖的package包/类
@Override
public boolean matches(Element root, Element element) {
      	List<Node> family = element.childNodes();
      	for (int i = 0; i < family.size(); i++) {
      		Node n = family.get(i);
      		if (!(n instanceof Comment || n instanceof XmlDeclaration || n instanceof DocumentType)) return false; 
      	}
      	return true;
}
 

import org.jsoup.nodes.XmlDeclaration; //导入依赖的package包/类
static Document parseByteData(ByteBuffer byteData, String charsetName, String baseUri, Parser parser) {
    String docData;
    Document doc = null;

    // look for BOM - overrides any other header or input
    charsetName = detectCharsetFromBom(byteData, charsetName);

    if (charsetName == null) { // determine from meta. safe first parse as UTF-8
        // look for <meta http-equiv="Content-Type" content="text/html;charset=gb2312"> or HTML5 <meta charset="gb2312">
        docData = Charset.forName(defaultCharset).decode(byteData).toString();
        doc = parser.parseInput(docData, baseUri);
        Element meta = doc.select("meta[http-equiv=content-type], meta[charset]").first();
        String foundCharset = null; // if not found, will keep utf-8 as best attempt
        if (meta != null) {
            if (meta.hasAttr("http-equiv")) {
                foundCharset = getCharsetFromContentType(meta.attr("content"));
            }
            if (foundCharset == null && meta.hasAttr("charset")) {
                foundCharset = meta.attr("charset");
            }
        }
        // look for <?xml encoding='ISO-8859-1'?>
        if (foundCharset == null && doc.childNode(0) instanceof XmlDeclaration) {
            XmlDeclaration prolog = (XmlDeclaration) doc.childNode(0);
            if (prolog.name().equals("xml")) {
                foundCharset = prolog.attr("encoding");
            }
        }
        foundCharset = validateCharset(foundCharset);

        if (foundCharset != null && !foundCharset.equals(defaultCharset)) { // need to re-decode
            foundCharset = foundCharset.trim().replaceAll("[\"']", "");
            charsetName = foundCharset;
            byteData.rewind();
            docData = Charset.forName(foundCharset).decode(byteData).toString();
            doc = null;
        }
    } else { // specified by content type header (or by user on file load)
        Validate.notEmpty(charsetName, "Must set charset arg to character set of file to parse. Set to null to attempt to detect from HTML");
        docData = Charset.forName(charsetName).decode(byteData).toString();
    }
    if (doc == null) {
        doc = parser.parseInput(docData, baseUri);
        doc.outputSettings().charset(charsetName);
    }
    return doc;
}
 

import org.jsoup.nodes.XmlDeclaration; //导入依赖的package包/类
static Document parseInputStream(InputStream input, String charsetName, String baseUri, Parser parser) throws IOException  {
    if (input == null) // empty body
        return new Document(baseUri);

    if (!(input instanceof ConstrainableInputStream))
        input = new ConstrainableInputStream(input, bufferSize, 0);

    Document doc = null;
    boolean fullyRead = false;

    // read the start of the stream and look for a BOM or meta charset
    input.mark(firstReadBufferSize);
    ByteBuffer firstBytes = readToByteBuffer(input, firstReadBufferSize - 1); // -1 because we read one more to see if completed
    fullyRead = input.read() == -1;
    input.reset();

    // look for BOM - overrides any other header or input
    BomCharset bomCharset = detectCharsetFromBom(firstBytes, charsetName);
    if (bomCharset != null) {
        charsetName = bomCharset.charset;
        input.skip(bomCharset.offset);
    }

    if (charsetName == null) { // determine from meta. safe first parse as UTF-8
        String docData = Charset.forName(defaultCharset).decode(firstBytes).toString();
        doc = parser.parseInput(docData, baseUri);

        // look for <meta http-equiv="Content-Type" content="text/html;charset=gb2312"> or HTML5 <meta charset="gb2312">
        Elements metaElements = doc.select("meta[http-equiv=content-type], meta[charset]");
        String foundCharset = null; // if not found, will keep utf-8 as best attempt
        for (Element meta : metaElements) {
            if (meta.hasAttr("http-equiv"))
                foundCharset = getCharsetFromContentType(meta.attr("content"));
            if (foundCharset == null && meta.hasAttr("charset"))
                foundCharset = meta.attr("charset");
            if (foundCharset != null)
                break;
        }

        // look for <?xml encoding='ISO-8859-1'?>
        if (foundCharset == null && doc.childNodeSize() > 0 && doc.childNode(0) instanceof XmlDeclaration) {
            XmlDeclaration prolog = (XmlDeclaration) doc.childNode(0);
            if (prolog.name().equals("xml"))
                foundCharset = prolog.attr("encoding");
        }
        foundCharset = validateCharset(foundCharset);
        if (foundCharset != null && !foundCharset.equalsIgnoreCase(defaultCharset)) { // need to re-decode. (case insensitive check here to match how validate works)
            foundCharset = foundCharset.trim().replaceAll("[\"']", "");
            charsetName = foundCharset;
            doc = null;
        } else if (!fullyRead) {
            doc = null;
        }
    } else { // specified by content type header (or by user on file load)
        Validate.notEmpty(charsetName, "Must set charset arg to character set of file to parse. Set to null to attempt to detect from HTML");
    }
    if (doc == null) {
        if (charsetName == null)
            charsetName = defaultCharset;
        BufferedReader reader = new BufferedReader(new InputStreamReader(input, charsetName), bufferSize);
        doc = parser.parseInput(reader, baseUri);
        doc.outputSettings().charset(charsetName);
    }
    input.close();
    return doc;
}