Question

以下格式是服务器的响应。我试图通过使用DOM解析这个问题，但得到的例外是“只允许一个根元素”。

<?xml version="1.0" encoding="UTF-8" ?>
  <responseCode>2000</responseCode>
  <responseText>Success</responseText>
  <response>
    <response1>on</response1>
    <response1>on</response1>
    <response1>on</response1>
    <response1>on</response1>
    <response1>on</response1>
  </response>
  <response>
    <response1>on</response1>
    <response1>on</response1>
    <response1>on</response1>
    <response1>on</response1>
    <response1>on</response1>
  </response>
  <response>
    <response1>on</response1>
    <response1>on</response1>
    <response1>on</response1>
    <response1>on</response1>
    <response1>on</response1>
  </response>

Answer 1

这是无效的XML。答复应如下：

<root>
  <responseCode>2000</responseCode>
  <responseText>Success</responseText>
  <response>
    <response1>on</response1>
    <response1>on</response1>
    <response1>on</response1>
    <response1>on</response1>
    <response1>on</response1>
  </response>
  <response>
    <response1>on</response1>
    <response1>on</response1>
    <response1>on</response1>
    <response1>on</response1>
    <response1>on</response1>
  </response>
  <response>
    <response1>on</response1>
    <response1>on</response1>
    <response1>on</response1>
    <response1>on</response1>
    <response1>on</response1>
  </response>
</root>

Answer 2

使用XmlPullParser解析会更容易，而且效率也更高

实施例。 XML文件内容（作为code.xml保存在外部存储中）

<?xml version="1.0" encoding="utf-8"?>
<countries>
 <country>
   <name>Iran</name>
   <phonecode>+98</phonecode>
   <code>IRI</code>
 </country>
 <country>
   <name>United State</name>
   <phonecode>+1</phonecode>
   <code>USA</code>
 </country>
</countries>

让我们开始解析它

首先创建一个Helper类

import android.util.Xml;
import org.xmlpull.v1.XmlPullParser;
import org.xmlpull.v1.XmlPullParserException;
import java.io.IOException;
import java.io.InputStream;

public class XmlDataParseHelper {

private XmlPullParser parser;
private static final String NULL = null;

/**
 * 
 * @param in
 * @throws XmlPullParserException
 * @throws IOException
 * @throws IllegalArgumentException
 */
public XmlDataParseHelper(InputStream in) throws XmlPullParserException,
        IOException, IllegalArgumentException {
    try {
        parser = Xml.newPullParser();
        parser.setFeature(XmlPullParser.FEATURE_PROCESS_NAMESPACES, false);
        parser.setInput(in, null);
        parser.nextTag();
    } catch (Exception e) {
        e.printStackTrace();
    }
}

/**
 * 
 * @return XmlPullParser
 */
public XmlPullParser getParser() {
    return parser;
}

/**
 * 
 * @param parser
 * @param tag
 * @return String
 * @throws IOException
 * @throws XmlPullParserException
 */
public static String readTag(XmlPullParser parser, String tag)
        throws IOException, XmlPullParserException {
    String tagData = "";
    parser.require(XmlPullParser.START_TAG, NULL, tag);
    if (parser.next() == XmlPullParser.TEXT) {
        tagData = parser.getText();
        parser.nextTag();
    }
    parser.require(XmlPullParser.END_TAG, NULL, tag);
    return tagData;
}

/**
 * 
 * @param parser
 * @param tag
 * @param attributeName
 * @return String
 * @throws IOException
 * @throws XmlPullParserException
 */
public static String readAttribute(XmlPullParser parser, String tag,
        String attributeName) throws IOException, XmlPullParserException {
    parser.require(XmlPullParser.START_TAG, NULL, tag);
    String attributeData = parser.getAttributeValue(NULL, attributeName);
    parser.nextTag();
    parser.require(XmlPullParser.END_TAG, NULL, tag);
    return attributeData;
}

}

将

public InputStream readFile(String fileName) throws FileNotFoundException,
        IOException {
//check external storage present
// else throw new IOException();

return new FileInputStream(Environment.getExternalStorageDirectory()
        + "/" + fileName);
}

将InputStream传递给另一个初始化XMLPullParser对象的方法

 public void readXmlFile(String fileName) {
 try {
    if (fileName.isEmpty())
    throw new NullPointerException();
    readData(new XmlDataParseHelper(readFile(fileName)).getParser());
 } catch (IOException e) {
       e.printStackTrace();
 } catch (XmlPullParserException e) {
       e.printStackTrace();
 } catch (IllegalArgumentException e) {
       e.printStackTrace();
 }
 }

Atlast将XMLPullParser object解析为

  public void readData(XmlPullParser parser)
            throws XmlPullParserException, IOException {
int eventType = parser.getEventType();
String tagName = "";
Log.w("Developer", "Reading file...");
while (eventType != XmlPullParser.END_DOCUMENT) {
    switch (eventType) {
        case XmlPullParser.START_DOCUMENT :
            Log.w("Developer", "Reading backup file...");
            break;
        case XmlPullParser.START_TAG :
            tagName = parser.getName();
            if (tagName.equals("countries")) {
                Log.w("XMLParse", "Start TAG countries");
                // do something when countries tag starts
            }
            if (tagName.equals("country")) {
                Log.w("XMLParse", "Start TAG country");
                // do some when country tag starts
            } else if (tagName.equals("name")) {
                // read tag value using XmlDataParseHelper class
                String countryName = XmlDataParseHelper.readTag(parser,
                                "name");
                Log.w("XmlParser", "Country name : "+countryName);
            } else if (tagName.equals("phonecode")) {
                String countryPhoneCode = 
                              XmlDataParseHelper.readTag(parser,"phonecode");
                Log.w("XmlParser", "Country Phone code : "+countryPhoneCode);
            } else if (tagName.equals("code")) {
                String countryCode = 
                             XmlDataParseHelper.readTag(parser, "code");
                Log.w("XmlParser", "Country code name : "+countryCode); 
            }
        break;
        case XmlPullParser.END_TAG :
            tagName = parser.getName();
            if (tagName.equals("countries")) {
                  // do something when counties tag is close.
            }           
        break;
    }
    eventType = parser.next();
}
Log.w("Developer", "File parsing complete...");
 }

要读取文件，只需使用存储在外部存储中的文件名称调用AsyncTask中的方法readXmlFile(String fileName)。

整个android工作示例代码在这里https://gist.github.com/rachitrm/7810837或分叉项目http://www.github.com/rachitrm/rm-xmlparser/

是否可以使用Android中的DOM解析器解析特定的XML？

2 个答案: