dom4j读取rss问题请教

Question

我刚刚学习xml,想利用资源做一个天气预报程序.下列是一个rss(xml文件),地址是http://xml.weather.yahoo.com/forecastrss?p=CHXX0120&u=c <?xml version="1.0" encoding="UTF-8" standalone="yes" ?> 
- <rss version="2.0" xmlns:yweather="http://xml.weather.yahoo.com/ns/rss/1.0" xmlns:geo="http://www.w3.org/2003/01/geo/wgs84_pos#">
- <channel>
  <title>Yahoo! Weather - Shenzhen, CH</title> 
  <link>http://us.rd.yahoo.com/dailynews/rss/weather/Shenzhen__CH/*http://xml.weather.yahoo.com/forecast/CHXX0120_c.html</link> 
  <description>Yahoo! Weather for Shenzhen, CH</description> 
  <language>en-us</language> 
  <lastBuildDate>Tue, 13 Dec 2005 10:00 am CST</lastBuildDate> 
  <ttl>60</ttl> 
  <yweather:location city="Shenzhen" region="" country="CH" /> 
  <yweather:units temperature="C" distance="km" pressure="mb" speed="kph" /> 
  <yweather:wind chill="14" direction="30" speed="21" /> 
  <yweather:atmosphere humidity="38" visibility="700" pressure="0" rising="0" /> 
  <yweather:astronomy sunrise="6:55 am" sunset="5:41 pm" /> 
- <image>
  <title>Yahoo! Weather</title> 
  <width>142</width> 
  <height>18</height> 
  <link>http://weather.yahoo.com/</link> 
  <url>http://us.i1.yimg.com/us.yimg.com/i/us/nws/th/main_142b.gif</url> 
  </image>
- <item>
  <title>Conditions for Shenzhen, CH at 10:00 am CST</title> 
  <geo:lat>22.53</geo:lat> 
  <geo:long>114.13</geo:long> 
  <link>http://us.rd.yahoo.com/dailynews/rss/weather/Shenzhen__CH/*http://xml.weather.yahoo.com/forecast/CHXX0120_c.html</link> 
  <pubDate>Tue, 13 Dec 2005 10:00 am CST</pubDate> 
  <yweather:condition text="Sunny" code="32" temp="14" date="Tue, 13 Dec 2005 10:00 am CST" /> 
- <description>
- <![CDATA[ 
 
<img src="http://us.i1.yimg.com/us.yimg.com/i/us/we/52/32.gif" /><br />
 <b>Current Conditions:</b><br />
 Sunny, 14 C<p />
 <b>Forecast:</b><BR />
  Wed - Sunny. High: 17 Low: 10<br />
  Thu - Sunny. High: 17 Low: 10<br />
  Fri - Sunny. High: 18 Low: 10<br />
 <br />
<a href="http://us.rd.yahoo.com/dailynews/rss/weather/Shenzhen__CH/*http://xml.weather.yahoo.com/forecast/CHXX0120_c.html">Full Forecast at Yahoo! Weather</a><BR/>
 (provided by The Weather Channel)<br/>
   ]]> 
  </description>
  <yweather:forecast day="Wed" date="13 Dec 2005" low="10" high="17" text="Sunny" code="32" /> 
  <yweather:forecast day="Thu" date="14 Dec 2005" low="10" high="17" text="Sunny" code="32" /> 
  <yweather:forecast day="Fri" date="15 Dec 2005" low="10" high="18" text="Sunny" code="32" /> 
  <guid isPermaLink="false">CHXX0120_2005_12_13_10_0_CST</guid> 
  </item>
  </channel>
  </rss>
- <!--  p2.weather.scd.yahoo.com uncompressed/chunked Tue Dec 13 18:49:30 PST 2005 
  -->

Answer 1

我的程序为:
String url="";
url="http://xml.weather.yahoo.com/forecastrss?p=CHXX0120&u=c";
SAXReader reader = new SAXReader();
Document doc = reader.read(url);
Element root = doc.getRootElement();

for ( Iterator i = root.elementIterator("channel"); i.hasNext();) {
Element foo = (Element) i.next();
out.print("最后更新时间："+foo.elementText("lastBuildDate")+"<br>");
}
这是ok的. 输出为:
最后更新时间：Tue, 13 Dec 2005 11:00 am CST
我想得到<yweather:location city="Shenzhen" region="" country="CH" /> 
中的ctiy的值Shenzhen怎么写?

Answer 2

foo.getChild("yweather:location").getAttribute("city").getValue()

Answer 3

dom4j中好象没有getChild().在哪个包下面呀

Answer 4

dom4j用foo.selectSingleNode("yweather:location").valueOf("@city")

Answer 5

for ( Iterator i = root.elementIterator("channel"); i.hasNext();) {
Element foo = (Element) i.next();
out.print("最后更新时间："+foo.elementText("lastBuildDate")+"<br/>");
out.print("城市："+foo.selectSingleNode("yweather:location").valueOf("@city")+"<br/>");
}out.print("城市："+foo.selectSingleNode("yweather:location").valueOf("@city")+"<br/>");
还是不行?

Answer 6

我试过可以的，你先看看out.print(foo.selectSingleNode("yweather:location").asXML());
看看是什么？贴出来看看

Answer 7

你把root,foo挨个print出来看看问题出在那一步

Answer 8

就是
out.print("城市："+foo.selectSingleNode("yweather:location").valueOf("@city")+"<br/>");
或
out.print(foo.selectSingleNode("yweather:location").asXML());
存在问题.
我加了有有问题,
不加显示:
最后更新时间：Tue, 13 Dec 2005 11:00 am CST

Answer 9

用xpath这样试试！
         Document doc = reader.read(yourFile);
         //定位，第一个里面的city值
         List node = doc.selectNodes( "//yweather:location[1]/@city" );
         Iterator rs_linkId = node.iterator();
         for (; rs_linkId.hasNext();) {
         Attribute att = (Attribute)rs_linkId.next();
         log.info(att.getValue());
         }

Answer 10

      Element channel=doc.getRootElement().element("channel");      System.out.print("标题："+channel.elementText("title")+"\n");
      System.out.print("描述："+channel.elementText("description")+"\n");
      System.out.print("时间："+channel.elementText("lastBuildDate")+"\n");
      System.out.print("ttl ："+channel.elementText("ttl")+"\n");      System.out.print("城市："+channel.valueOf("yweather:location/@city")+
                       " "+channel.valueOf("yweather:location/@region")+
                       " "+channel.valueOf("yweather:location/@country")+"\n");