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这篇CFSDN的博客文章Android 使用Pull方法解析XML文件的方法由作者收集整理，如果你对这篇文章有兴趣，记得点赞哟.

Pull解析方法给应用程序完全的控制文档该怎么样被解析。Android中对Pull方法提供了支持的API，主要是 。

复制代码 代码如下

org.xmlpull.v1.XmlPullParser; org.xmlpull.v1.XmlPullParserFactory,

二个类，其中主要使用的是XmlPullParser，XmlPullParserFactory是一个工厂，用于构建XmlPullParser对象。 应用程序通过调用XmlPullParser.next()等方法来产生Event，然后再处理Event。可以看到它与Push方法的不同，Push方法是由Parser自己主动产生Event，回调给应用程序。而Pull方法是主动的调用Parser的方法才能产生事件。 假如XML中的语句是这样的："<author country="United States">James Elliott</author>"，author是TAG，country是ATTRIBUTE，"James Elliott"是TEXT。 要想解析文档先要构建一个XmlPullParser对象 。

复制代码 代码如下

final XmlPullParserFactory factory = XmlPullParserFactory.newInstance(); factory.setNamespaceAware(true); final XmlPullParser parser = factory.newPullParser(),

Pull解析是一个遍历文档的过程，每次调用next()，nextTag(), nextToken()和nextText()都会向前推进文档，并使Parser停留在某些事件上面，但是不能倒退。 然后把文档设置给Parser 。

复制代码 代码如下

parser.setInput(new StringReader("<author country=\"United States\">James Elliott</author>"),

这时，文档刚被初始化，所以它应该位于文档的开始，事件应该是START_DOCUMENT，可以通过XmlPullParser.getEventType()来获取。然后调用next()会产生 START_TAG，这个事件告诉应用程序一个标签已经开始了，调用getName()会返回"author";再next()会产生 TEXT事件，调用getText()会返回"James Elliott"，再next()，会产生 END_TAG，这个告诉你一个标签已经处理完了，再next()，会产生 END_DOCUMENT，它告诉你整个文档已经处理完成了。 除了next()外，nextToken()也可以使用，只不过它会返回更加详细的事件，比如 COMMENT, CDSECT, DOCDECL, ENTITY等等非常详细的信息。如果程序得到比较底层的信息，可以用nextToken()来驱动并处理详细的事件。需要注意一点的是TEXT事件是有可能返回空白的White Spaces比如换行符或空格等。 另外有二个非常实用的方法nextTag()和nextText() nextTag()--首先它会忽略White Spaces，如果可以确定下一个是START_TAG或END_TAG，就可以调用nextTag()直接跳过去。通常它有二个用处：当START_TAG时，如果能确定这个TAG含有子TAG，那么就可以调用nextTag()产生子标签的START_TAG事件；当END_TAG时，如果确定不是文档结尾，就可以调用nextTag()产生下一个标签的START_TAG。在这二种情况下如果用next()会有TEXT事件，但返回的是换行符或空白符。 nextText()--它只能在START_TAG时调用。当下一个元素是TEXT时，TEXT的内容会返回；当下一个元素是END_TAG时，也就是说这个标签的内容为空，那么空字串返回；这个方法返回后，Parser会停在END_TAG上。比如:

复制代码 代码如下

<author>James Elliott</author> <author></author> <author/> 。

当START_TAG时，调用nextText()，依次返回： "James Elliott" ""(empty) ""(empty) 这个方法在处理没有子标签的标签时很有用。比如:

复制代码 代码如下

<title>What Is Hibernate</title> <author>James Elliott</author> <category>Web</category> 。

就可以用以下代码来处理:

复制代码 代码如下

        while (eventType != XmlPullParser.END_TAG) {             switch (eventType) {             case XmlPullParser.START_TAG:                 tag = parser.getName();                 final String content = parser.nextText();                 Log.e(TAG, tag + ": [" + content + "]");                 eventType = parser.nextTag();                 break;             default:                 break;             }         } 。

这就要比用next()来处理方便多了，可读性也大大的加强了。 最后附上一个解析XML的实例Android程序 。

复制代码 代码如下

import java.io.IOException; import java.io.InputStream; import org.xmlpull.v1.XmlPullParser; import org.xmlpull.v1.XmlPullParserException; import org.xmlpull.v1.XmlPullParserFactory; import android.util.Log; public class RssPullParser extends RssParser {     private final String TAG = FeedSettings.GLOBAL_TAG;     private InputStream mInputStream;     public RssPullParser(InputStream is) {         mInputStream = is;     }     public void parse() throws ReaderBaseException, XmlPullParserException, IOException {         if (mInputStream == null) {             throw new ReaderBaseException("no input source, did you initialize this class correctly?");         }         final XmlPullParserFactory factory = XmlPullParserFactory.newInstance();         factory.setNamespaceAware(true);         final XmlPullParser parser = factory.newPullParser();         parser.setInput(mInputStream);         int eventType = parser.getEventType();         if (eventType != XmlPullParser.START_DOCUMENT) {             throw new ReaderBaseException("Not starting with 'start_document'");         }         eventType = parseRss(parser);         if (eventType != XmlPullParser.END_DOCUMENT) {             throw new ReaderBaseException("not ending with 'end_document', do you finish parsing?");         }         if (mInputStream != null) {             mInputStream.close();         } else {             Log.e(TAG, "inputstream is null, XmlPullParser closed it??");         }     }     /**      * Parsing the Xml document. Current type must be Start_Document.      * After calling this, Parser is positioned at END_DOCUMENT.      * @param parser      * @return event end_document      * @throws XmlPullParserException      * @throws ReaderBaseException      * @throws IOException      */     private int parseRss(XmlPullParser parser) throws XmlPullParserException, ReaderBaseException, IOException {         int eventType = parser.getEventType();         if (eventType != XmlPullParser.START_DOCUMENT) {             throw new ReaderBaseException("not starting with 'start_document', is this a new document?");         }         Log.e(TAG, "starting document, are you aware of that!");         eventType = parser.next();         while (eventType != XmlPullParser.END_DOCUMENT) {             switch (eventType) {             case XmlPullParser.START_TAG: {                 Log.e(TAG, "start tag: '" + parser.getName() + "'");                 final String tagName = parser.getName();                 if (tagName.equals(RssFeed.TAG_RSS)) {                     Log.e(TAG, "starting an RSS feed <<");                     final int attrSize = parser.getAttributeCount();                     for (int i = 0; i < attrSize; i++) {                         Log.e(TAG, "attr '" + parser.getAttributeName(i) + "=" + parser.getAttributeValue(i) + "'");                     }                 } else if (tagName.equals(RssFeed.TAG_CHANNEL)) {                     Log.e(TAG, "\tstarting an Channel <<");                     parseChannel(parser);                 }                 break;             }             case XmlPullParser.END_TAG: {                 Log.e(TAG, "end tag: '" + parser.getName() + "'");                 final String tagName = parser.getName();                 if (tagName.equals(RssFeed.TAG_RSS)) {                     Log.e(TAG, ">> edning an RSS feed");                 } else if (tagName.equals(RssFeed.TAG_CHANNEL)) {                     Log.e(TAG, "\t>> ending an Channel");                     }                 break;             }             default:                 break;             }             eventType = parser.next();         }         Log.e(TAG, "end of document, it is over");         return parser.getEventType();     }     /**      * Parse a channel. MUST be start tag of an channel, otherwise exception thrown.      * Param XmlPullParser      * After calling this function, parser is positioned at END_TAG of Channel.      * return end tag of a channel      * @throws XmlPullParserException      * @throws ReaderBaseException      * @throws IOException      */     private int parseChannel(XmlPullParser parser) throws XmlPullParserException, ReaderBaseException, IOException {         int eventType = parser.getEventType();         String tagName = parser.getName();         if (eventType != XmlPullParser.START_TAG || !RssFeed.TAG_CHANNEL.equals(tagName)) {             throw new ReaderBaseException("not start with 'start tag', is this a start of a channel?");         }         Log.e(TAG, "\tstarting " + tagName);         eventType = parser.nextTag();         while (eventType != XmlPullParser.END_TAG) {             switch (eventType) {             case XmlPullParser.START_TAG: {                 final String tag = parser.getName();                 if (tag.equals(RssFeed.TAG_IMAGE)) {                     parseImage(parser);                 } else if (tag.equals(RssFeed.TAG_ITEM)) {                     parseItem(parser);                 } else {                     final String content = parser.nextText();                     Log.e(TAG, tag + ": [" + content + "]");                 }                 // now it SHOULD be at END_TAG, ensure it                 if (parser.getEventType() != XmlPullParser.END_TAG) {                     throw new ReaderBaseException("not ending with 'end tag', did you finish parsing sub item?");                 }                 eventType = parser.nextTag();                 break;             }             default:                 break;             }         }         Log.e(TAG, "\tending " + parser.getName());         return parser.getEventType();     }     /**      * Parse image in a channel.      * Precondition: position must be at START_TAG and tag MUST be 'image'      * Postcondition: position is END_TAG of '/image'      * @throws IOException      * @throws XmlPullParserException      * @throws ReaderBaseException      */     private int parseImage(XmlPullParser parser) throws XmlPullParserException, IOException, ReaderBaseException {         int eventType = parser.getEventType();         String tag = parser.getName();         if (eventType != XmlPullParser.START_TAG || !RssFeed.TAG_IMAGE.equals(tag)) {             throw new ReaderBaseException("not start with 'start tag', is this a start of an image?");         }         Log.e(TAG, "\t\tstarting image " + tag);         eventType = parser.nextTag();         while (eventType != XmlPullParser.END_TAG) {             switch (eventType) {             case XmlPullParser.START_TAG:                 tag = parser.getName();                 Log.e(TAG, tag + ": [" + parser.nextText() + "]");                 // now it SHOULD be at END_TAG, ensure it                 if (parser.getEventType() != XmlPullParser.END_TAG) {                     throw new ReaderBaseException("not ending with 'end tag', did you finish parsing sub item?");                 }                 eventType = parser.nextTag();                 break;             default:                 break;             }         }         Log.e(TAG, "\t\tending image " + parser.getName());         return parser.getEventType();     }     /**      * Parse an item in a channel.      * Precondition: position must be at START_TAG and tag MUST be 'item'      * Postcondition: position is END_TAG of '/item'      * @throws IOException      * @throws XmlPullParserException      * @throws ReaderBaseException      */     private int parseItem(XmlPullParser parser) throws XmlPullParserException, IOException, ReaderBaseException {         int eventType = parser.getEventType();         String tag = parser.getName();         if (eventType != XmlPullParser.START_TAG || !RssFeed.TAG_ITEM.equals(tag)) {             throw new ReaderBaseException("not start with 'start tag', is this a start of an item?");         }         Log.e(TAG, "\t\tstarting " + tag);         eventType = parser.nextTag();         while (eventType != XmlPullParser.END_TAG) {             switch (eventType) {             case XmlPullParser.START_TAG:                 tag = parser.getName();                 final String content = parser.nextText();                 Log.e(TAG, tag + ": [" + content + "]");                 // now it SHOULD be at END_TAG, ensure it                 if (parser.getEventType() != XmlPullParser.END_TAG) {                     throw new ReaderBaseException("not ending with 'end tag', did you finish parsing sub item?");                 }                 eventType = parser.nextTag();                 break;             default:                 break;             }         }         Log.e(TAG, "\t\tending " + parser.getName());         return parser.getEventType();     } } 。

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