android.util.XML介绍

android为我们提供了一系列的和XML操作相关的方法，这些方法都位于类android.util.XML中，主要方法如下

asAttributeSet()方法：

      将xml中的内容以加载到一个AttributeSet中，以键值对的形式存储。一般被用于描述某个图形表现形式。和android:text这种标签的功能一样。

其他的方法也没什么好解释的了。

这里粘贴处XML类的源代码，对于其实现过程就一目了然了

  

   

    

     

    
    

     

      /*
     
    
   

    

     

    
    

     

       * Copyright (C) 2007 The Android Open Source Project
     
    
   

    

     

    
    

     

       *
     
    
   

    

     

    
    

     

       * Licensed under the Apache License, Version 2.0 (the "License");
     
    
   

    

     

    
    

     

       * you may not use this file except in compliance with the License.
     
    
   

    

     

    
    

     

       * You may obtain a copy of the License at
     
    
   

    

     

    
    

     

       *
     
    
   

    

     

    
    

     

       * http://www.apache.org/licenses/LICENSE-2.0
     
    
   

    

     

    
    

     

       *
     
    
   

    

     

    
    

     

       * Unless required by applicable law or agreed to in writing, software
     
    
   

    

     

    
    

     

       * distributed under the License is distributed on an "AS IS" BASIS,
     
    
   

    

     

    
    

     

       * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
     
    
   

    

     

    
    

     

       * See the License for the specific language governing permissions and
     
    
   

    

     

    
    

     

       * limitations under the License.
     
    
   

    

     

    
    

     

       */
     
    
   

    

     

    
    

     
 
     
    
   

    

     

    
    

     

      package android.util;
     
    
   

    

     

    
    

     
 
     
    
   

    

     

    
    

     

      import org.xml.sax.ContentHandler;
     
    
   

    

     

    
    

     

      import org.xml.sax.InputSource;
     
    
   

    

     

    
    

     

      import org.xml.sax.SAXException;
     
    
   

    

     

    
    

     

      import org.xml.sax.XMLReader;
     
    
   

    

     

    
    

     

      import org.xmlpull.v1.XmlPullParser;
     
    
   

    

     

    
    

     

      import org.xmlpull.v1.XmlSerializer;
     
    
   

    

     

    
    

     

      import org.xmlpull.v1.XmlPullParserException;
     
    
   

    

     

    
    

     

      import org.xmlpull.v1.XmlPullParserFactory;
     
    
   

    

     

    
    

     
 
     
    
   

    

     

    
    

     

      import java.io.IOException;
     
    
   

    

     

    
    

     

      import java.io.InputStream;
     
    
   

    

     

    
    

     

      import java.io.Reader;
     
    
   

    

     

    
    

     

      import java.io.StringReader;
     
    
   

    

     

    
    

     

      import java.io.UnsupportedEncodingException;
     
    
   

    

     

    
    

     
 
     
    
   

    

     

    
    

     

      import org.apache.harmony.xml.ExpatPullParser;
     
    
   

    

     

    
    

     

      import org.apache.harmony.xml.ExpatReader;
     
    
   

    

     

    
    

     
 
     
    
   

    

     

    
    

     

      /**
     
    
   

    

     

    
    

     

       * XML utility methods.
     
    
   

    

     

    
    

     

       */
     
    
   

    

     

    
    

     

      public class Xml {
     
    
   

    

     

    
    

     
 
     
    
   

    

     

    
    

     
    /**
     
    
   

    

     

    
    

     

       * {@link org.xmlpull.v1.XmlPullParser} "relaxed" feature name.
     
    
   

    

     

    
    

     

       *
     
    
   

    

     

    
    

     

       * @see <a href="http://xmlpull.org/v1/doc/features.html#relaxed" mce_href="http://xmlpull.org/v1/doc/features.html#relaxed">
     
    
   

    

     

    
    

     

       * specification</a>
     
    
   

    

     

    
    

     

       */
     
    
   

    

     

    
    

     
    public static String FEATURE_RELAXED = ExpatPullParser.FEATURE_RELAXED;
     
    
   

    

     

    
    

     
 
     
    
   

    

     

    
    

     
    /**
     
    
   

    

     

    
    

     

       * Parses the given xml string and fires events on the given SAX handler.
     
    
   

    

     

    
    

     

       */
     
    
   

    

     

    
    

     
    public static void parse(String xml, ContentHandler contentHandler)
     
    
   

    

     

    
    

     
            throws SAXException {
     
    
   

    

     

    
    

     
        try {
     
    
   

    

     

    
    

     
            XMLReader reader = new ExpatReader();
     
    
   

    

     

    
    

     

                  reader.setContentHandler(contentHandler);
     
    
   

    

     

    
    

     

                  reader.parse(new InputSource(new StringReader(xml)));
     
    
   

    

     

    
    

     

              }
     
    
   

    

     

    
    

     
        catch (IOException e) {
     
    
   

    

     

    
    

     
            throw new AssertionError(e);
     
    
   

    

     

    
    

     

              }
     
    
   

    

     

    
    

     

          }
     
    
   

    

     

    
    

     
 
     
    
   

    

     

    
    

     
    /**
     
    
   

    

     

    
    

     

       * Parses xml from the given reader and fires events on the given SAX
     
    
   

    

     

    
    

     

       * handler.
     
    
   

    

     

    
    

     

       */
     
    
   

    

     

    
    

     
    public static void parse(Reader in, ContentHandler contentHandler)
     
    
   

    

     

    
    

     
            throws IOException, SAXException {
     
    
   

    

     

    
    

     
        XMLReader reader = new ExpatReader();
     
    
   

    

     

    
    

     

              reader.setContentHandler(contentHandler);
     
    
   

    

     

    
    

     

              reader.parse(new InputSource(in));
     
    
   

    

     

    
    

     

          }
     
    
   

    

     

    
    

     
 
     
    
   

    

     

    
    

     
    /**
     
    
   

    

     

    
    

     

       * Parses xml from the given input stream and fires events on the given SAX
     
    
   

    

     

    
    

     

       * handler.
     
    
   

    

     

    
    

     

       */
     
    
   

    

     

    
    

     
    public static void parse(InputStream in, Encoding encoding,
     
    
   

    

     

    
    

     

       ContentHandler contentHandler) throws IOException, SAXException {
     
    
   

    

     

    
    

     
        try {
     
    
   

    

     

    
    

     
            XMLReader reader = new ExpatReader();
     
    
   

    

     

    
    

     

                  reader.setContentHandler(contentHandler);
     
    
   

    

     

    
    

     
            InputSource source = new InputSource(in);
     
    
   

    

     

    
    

     

                  source.setEncoding(encoding.expatName);
     
    
   

    

     

    
    

     

                  reader.parse(source);
     
    
   

    

     

    
    

     

              } catch (IOException e) {
     
    
   

    

     

    
    

     
            throw new AssertionError(e);
     
    
   

    

     

    
    

     

              }
     
    
   

    

     

    
    

     

          }
     
    
   

    

     

    
    

     
 
     
    
   

    

     

    
    

     
    /**
     
    
   

    

     

    
    

     

       * Creates a new pull parser with namespace support.
     
    
   

    

     

    
    

     

       *
     
    
   

    

     

    
    

     

       * <p><b>Note:</b> This is actually slower than the SAX parser, and it's not
     
    
   

    

     

    
    

     

       * fully implemented. If you need a fast, mostly implemented pull parser,
     
    
   

    

     

    
    

     

       * use this. If you need a complete implementation, use KXML.
     
    
   

    

     

    
    

     

       */
     
    
   

    

     

    
    

     
    public static XmlPullParser newPullParser() {
     
    
   

    

     

    
    

     
        ExpatPullParser parser = new ExpatPullParser();
     
    
   

    

     

    
    

     

              parser.setNamespaceProcessingEnabled(true);
     
    
   

    

     

    
    

     
        return parser;
     
    
   

    

     

    
    

     

          }
     
    
   

    

     

    
    

     
 
     
    
   

    

     

    
    

     
    /**
     
    
   

    

     

    
    

     

       * Creates a new xml serializer.
     
    
   

    

     

    
    

     

       */
     
    
   

    

     

    
    

     
    public static XmlSerializer newSerializer() {
     
    
   

    

     

    
    

     
        try {
     
    
   

    

     

    
    

     
            return XmlSerializerFactory.instance.newSerializer();
     
    
   

    

     

    
    

     

              } catch (XmlPullParserException e) {
     
    
   

    

     

    
    

     
            throw new AssertionError(e);
     
    
   

    

     

    
    

     

              }
     
    
   

    

     

    
    

     

          }
     
    
   

    

     

    
    

     
 
     
    
   

    

     

    
    

     
    /** Factory for xml serializers. Initialized on demand. */
     
    
   

    

     

    
    

     
    static class XmlSerializerFactory {
     
    
   

    

     

    
    

     
        static final String TYPE
     
    
   

    

     

    
    

     
                = "org.kxml2.io.KXmlParser,org.kxml2.io.KXmlSerializer";
     
    
   

    

     

    
    

     
        static final XmlPullParserFactory instance;
     
    
   

    

     

    
    

     
        static {
     
    
   

    

     

    
    

     
            try {
     
    
   

    

     

    
    

     

                      instance = XmlPullParserFactory.newInstance(TYPE, null);
     
    
   

    

     

    
    

     

                  } catch (XmlPullParserException e) {
     
    
   

    

     

    
    

     
                throw new AssertionError(e);
     
    
   

    

     

    
    

     

                  }
     
    
   

    

     

    
    

     

              }
     
    
   

    

     

    
    

     

          }
     
    
   

    

     

    
    

     
 
     
    
   

    

     

    
    

     
    /**
     
    
   

    

     

    
    

     

       * Supported character encodings.
     
    
   

    

     

    
    

     

       */
     
    
   

    

     

    
    

     
    public enum Encoding {
     
    
   

    

     

    
    

     
 
     
    
   

    

     

    
    

     

              US_ASCII("US-ASCII"),
     
    
   

    

     

    
    

     

              UTF_8("UTF-8"),
     
    
   

    

     

    
    

     

              UTF_16("UTF-16"),
     
    
   

    

     

    
    

     

              ISO_8859_1("ISO-8859-1");
     
    
   

    

     

    
    

     
 
     
    
   

    

     

    
    

     
        final String expatName;
     
    
   

    

     

    
    

     
 
     
    
   

    

     

    
    

     

              Encoding(String expatName) {
     
    
   

    

     

    
    

     
            this.expatName = expatName;
     
    
   

    

     

    
    

     

              }
     
    
   

    

     

    
    

     

          }
     
    
   

    

     

    
    

     
 
     
    
   

    

     

    
    

     
    /**
     
    
   

    

     

    
    

     

       * Finds an encoding by name. Returns UTF-8 if you pass {@code null}.
     
    
   

    

     

    
    

     

       */
     
    
   

    

     

    
    

     
    public static Encoding findEncodingByName(String encodingName)
     
    
   

    

     

    
    

     
            throws UnsupportedEncodingException {
     
    
   

    

     

    
    

     
        if (encodingName == null) {
     
    
   

    

     

    
    

     
            return Encoding.UTF_8;
     
    
   

    

     

    
    

     

              }
     
    
   

    

     

    
    

     
 
     
    
   

    

     

    
    

     
        for (Encoding encoding : Encoding.values()) {
     
    
   

    

     

    
    

     
            if (encoding.expatName.equalsIgnoreCase(encodingName))
     
    
   

    

     

    
    

     
                return encoding;
     
    
   

    

     

    
    

     

              }
     
    
   

    

     

    
    

     
        throw new UnsupportedEncodingException(encodingName);
     
    
   

    

     

    
    

     

          }
     
    
   

    

     

    
    

     
    
     
    
   

    

     

    
    

     
    /**
     
    
   

    

     

    
    

     

       * Return an AttributeSet interface for use with the given XmlPullParser.
     
    
   

    

     

    
    

     

       * If the given parser itself implements AttributeSet, that implementation
     
    
   

    

     

    
    

     

       * is simply returned. Otherwise a wrapper class is
     
    
   

    

     

    
    

     

       * instantiated on top of the XmlPullParser, as a proxy for retrieving its
     
    
   

    

     

    
    

     

       * attributes, and returned to you.
     
    
   

    

     

    
    

     

       * 
     
    
   

    

     

    
    

     

       * @param parser The existing parser for which you would like an
     
    
   

    

     

    
    

     

       * AttributeSet.
     
    
   

    

     

    
    

     

       * 
     
    
   

    

     

    
    

     

       * @return An AttributeSet you can use to retrieve the
     
    
   

    

     

    
    

     

       * attribute values at each of the tags as the parser moves
     
    
   

    

     

    
    

     

       * through its XML document.
     
    
   

    

     

    
    

     

       * 
     
    
   

    

     

    
    

     

       * @see AttributeSet
     
    
   

    

     

    
    

     

       */
     
    
   

    

     

    
    

     
    public static AttributeSet asAttributeSet(XmlPullParser parser) {
     
    
   

    

     

    
    

     
        return (parser instanceof AttributeSet)
     
    
   

    

     

    
    

     

                      ? (AttributeSet) parser
     
    
   

    

     

    
    

     

                      : new XmlPullAttributes(parser);
     
    
   

    

     

    
    

     

          }
     
    
   

    

     

    
    

     

      }
     
    
  
 

文章来源: panda1234lee.blog.csdn.net，作者：panda1234lee，版权归原作者所有，如需转载，请联系作者。

原文链接：panda1234lee.blog.csdn.net/article/details/8831947