我正在尝试从 RSS 提要中提取一些 XHTML，以便将其放置在 WebView 中。有问题的 RSS 提要有一个名为的标签<content>，内容中的字符是 XHTML。（我要配对的网站是博客提要）尝试提取此内容的最佳方法是什么？这些<字符使我的解析器感到困惑。我已经尝试过 DOM 和 SAX，但都不能很好地处理这个问题。
以下是请求的 XML 示例。在这种情况下，我希望内容标记内的 XHTML 基本上是一个字符串。<content> XHTML </content>
编辑：根据 ignyhere 的建议，我尝试过 XPath，但我仍然遇到同样的问题。这是我的测试的 pastebin 样本。
我会尝试用 XPath 攻击它。像这样的东西会起作用吗？
public static String parseAtom (InputStream atomIS)
throws Exception {
// Below should yield the second content block
String xpathString = "(//*[starts-with(name(),"content")])[2]";
// or, String xpathString = "//*[name() = 'content'][2]";
// remove the '[2]' to get all content tags or get the count,
// if needed, and then target specific blocks
//String xpathString = "count(//*[starts-with(name(),"content")])";
// note the evaluate expression below returns a glob and not a node set
XPathFactory xpf = XPathFactory.newInstance ();
XPath xpath = xpf.newXPath ();
XPathExpression xpathCompiled = xpath.compile (xpathString);
// use the first to recast and evaluate as NodeList
//Object atomOut = xpathCompiled.evaluate (
// new InputSource (atomIS), XPathConstants.NODESET);
String atomOut = xpathCompiled.evaluate (
new InputSource (atomIS), XPathConstants.STRING);
System.out.println (atomOut);
return atomOut;
}
它并不漂亮，但这是我用来解析来自 Blogger 的 ATOM 提要的（本质），它使用XmlPullParser。代码很恶心，但它来自一个真实的应用程序。无论如何，你可能会得到它的一般味道。
final String TAG_FEED = "feed";
public int parseXml(Reader reader) {
XmlPullParserFactory factory = null;
StringBuilder out = new StringBuilder();
int entries = 0;
try {
factory = XmlPullParserFactory.newInstance();
factory.setNamespaceAware(true);
XmlPullParser xpp = factory.newPullParser();
xpp.setInput(reader);
while (true) {
int eventType = xpp.next();
if (eventType == XmlPullParser.END_DOCUMENT) {
break;
} else if (eventType == XmlPullParser.START_DOCUMENT) {
out.append("Start document\n");
} else if (eventType == XmlPullParser.START_TAG) {
String tag = xpp.getName();
// out.append("Start tag " + tag + "\n");
if (TAG_FEED.equalsIgnoreCase(tag)) {
entries = parseFeed(xpp);
}
} else if (eventType == XmlPullParser.END_TAG) {
// out.append("End tag " + xpp.getName() + "\n");
} else if (eventType == XmlPullParser.TEXT) {
// out.append("Text " + xpp.getText() + "\n");
}
}
out.append("End document\n");
} catch (XmlPullParserException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
// return out.toString();
return entries;
}
private int parseFeed(XmlPullParser xpp) throws XmlPullParserException, IOException {
int depth = xpp.getDepth();
assert (depth == 1);
int eventType;
int entries = 0;
xpp.require(XmlPullParser.START_TAG, null, TAG_FEED);
while (((eventType = xpp.next()) != XmlPullParser.END_DOCUMENT) && (xpp.getDepth() > depth)) {
// loop invariant: At this point, the parser is not sitting on
// end-of-document, and is at a level deeper than where it started.
if (eventType == XmlPullParser.START_TAG) {
String tag = xpp.getName();
// Log.d("parseFeed", "Start tag: " + tag); // Uncomment to debug
if (FeedEntry.TAG_ENTRY.equalsIgnoreCase(tag)) {
FeedEntry feedEntry = new FeedEntry(xpp);
feedEntry.persist(this);
entries++;
// Log.d("FeedEntry", feedEntry.title); // Uncomment to debug
// xpp.require(XmlPullParser.END_TAG, null, tag);
}
}
}
assert (depth == 1);
return entries;
}
class FeedEntry {
String id;
String published;
String updated;
// Timestamp lastRead;
String title;
String subtitle;
String authorName;
int contentType;
String content;
String preview;
String origLink;
String thumbnailUri;
// Media media;
static final String TAG_ENTRY = "entry";
static final String TAG_ENTRY_ID = "id";
static final String TAG_TITLE = "title";
static final String TAG_SUBTITLE = "subtitle";
static final String TAG_UPDATED = "updated";
static final String TAG_PUBLISHED = "published";
static final String TAG_AUTHOR = "author";
static final String TAG_CONTENT = "content";
static final String TAG_TYPE = "type";
static final String TAG_ORIG_LINK = "origLink";
static final String TAG_THUMBNAIL = "thumbnail";
static final String ATTRIBUTE_URL = "url";
/**
* Create a FeedEntry by pulling its bits out of an XML Pull Parser. Side effect: Advances
* XmlPullParser.
*
* @param xpp
*/
public FeedEntry(XmlPullParser xpp) {
int eventType;
int depth = xpp.getDepth();
assert (depth == 2);
try {
xpp.require(XmlPullParser.START_TAG, null, TAG_ENTRY);
while (((eventType = xpp.next()) != XmlPullParser.END_DOCUMENT)
&& (xpp.getDepth() > depth)) {
if (eventType == XmlPullParser.START_TAG) {
String tag = xpp.getName();
if (TAG_ENTRY_ID.equalsIgnoreCase(tag)) {
id = Util.XmlPullTag(xpp, TAG_ENTRY_ID);
} else if (TAG_TITLE.equalsIgnoreCase(tag)) {
title = Util.XmlPullTag(xpp, TAG_TITLE);
} else if (TAG_SUBTITLE.equalsIgnoreCase(tag)) {
subtitle = Util.XmlPullTag(xpp, TAG_SUBTITLE);
} else if (TAG_UPDATED.equalsIgnoreCase(tag)) {
updated = Util.XmlPullTag(xpp, TAG_UPDATED);
} else if (TAG_PUBLISHED.equalsIgnoreCase(tag)) {
published = Util.XmlPullTag(xpp, TAG_PUBLISHED);
} else if (TAG_CONTENT.equalsIgnoreCase(tag)) {
int attributeCount = xpp.getAttributeCount();
for (int i = 0; i < attributeCount; i++) {
String attributeName = xpp.getAttributeName(i);
if (attributeName.equalsIgnoreCase(TAG_TYPE)) {
String attributeValue = xpp.getAttributeValue(i);
if (attributeValue
.equalsIgnoreCase(FeedReaderContract.FeedEntry.ATTRIBUTE_NAME_HTML)) {
contentType = FeedReaderContract.FeedEntry.CONTENT_TYPE_HTML;
} else if (attributeValue
.equalsIgnoreCase(FeedReaderContract.FeedEntry.ATTRIBUTE_NAME_XHTML)) {
contentType = FeedReaderContract.FeedEntry.CONTENT_TYPE_XHTML;
} else {
contentType = FeedReaderContract.FeedEntry.CONTENT_TYPE_TEXT;
}
break;
}
}
content = Util.XmlPullTag(xpp, TAG_CONTENT);
extractPreview();
} else if (TAG_AUTHOR.equalsIgnoreCase(tag)) {
// Skip author for now -- it is complicated
int authorDepth = xpp.getDepth();
assert (authorDepth == 3);
xpp.require(XmlPullParser.START_TAG, null, TAG_AUTHOR);
while (((eventType = xpp.next()) != XmlPullParser.END_DOCUMENT)
&& (xpp.getDepth() > authorDepth)) {
}
assert (xpp.getDepth() == 3);
xpp.require(XmlPullParser.END_TAG, null, TAG_AUTHOR);
} else if (TAG_ORIG_LINK.equalsIgnoreCase(tag)) {
origLink = Util.XmlPullTag(xpp, TAG_ORIG_LINK);
} else if (TAG_THUMBNAIL.equalsIgnoreCase(tag)) {
thumbnailUri = Util.XmlPullAttribute(xpp, tag, null, ATTRIBUTE_URL);
} else {
@SuppressWarnings("unused")
String throwAway = Util.XmlPullTag(xpp, tag);
}
}
} // while
} catch (XmlPullParserException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
assert (xpp.getDepth() == 2);
}
}
public static String XmlPullTag(XmlPullParser xpp, String tag)
throws XmlPullParserException, IOException {
xpp.require(XmlPullParser.START_TAG, null, tag);
String itemText = xpp.nextText();
if (xpp.getEventType() != XmlPullParser.END_TAG) {
xpp.nextTag();
}
xpp.require(XmlPullParser.END_TAG, null, tag);
return itemText;
}
public static String XmlPullAttribute(XmlPullParser xpp,
String tag, String namespace, String name)
throws XmlPullParserException, IOException {
assert (!TextUtils.isEmpty(tag));
assert (!TextUtils.isEmpty(name));
xpp.require(XmlPullParser.START_TAG, null, tag);
String itemText = xpp.getAttributeValue(namespace, name);
if (xpp.getEventType() != XmlPullParser.END_TAG) {
xpp.nextTag();
}
xpp.require(XmlPullParser.END_TAG, null, tag);
return itemText;
}
I'll give you a hint: None of the return values matter. The data is saved into a database by a method (not shown) called at this line:
feedEntry.persist(this);
我可以在这里看到你的问题，这些解析器没有产生正确结果的原因是因为你的<content>标签的内容没有被包装到<![CDATA[ ]]>，我会做什么，直到我找到更合适的解决方案，我会使用快速而肮脏的技巧：
private void parseFile(String fileName) throws IOException {
String line;
BufferedReader br = new BufferedReader(new FileReader(new File(fileName)));
StringBuilder sb = new StringBuilder();
boolean match = false;
while ((line = br.readLine()) != null) {
if(line.contains("<content")){
sb.append(line);
sb.append("\n");
match = true;
continue;
}
if(match){
sb.append(line);
sb.append("\n");
match = false;
}
if(line.contains("</content")){
sb.append(line);
sb.append("\n");
}
}
System.out.println(sb.toString());
}
这将为您提供 String 中的所有内容。您可以通过稍微修改此方法来选择性地将它们分开，或者如果您不需要实际<content>，您也可以将其过滤掉。