Java:解析 XML 文件时出现问题

Question

我有以下 XML，我正在尝试打印某些节点的值。例如，使用以下代码我想打印

 NodeList list = doc.getElementsByTagName("photo");
 element = (Element)list.item(0);
 list = element.getChildNodes();
 System.out.println(list.item(0).getNodeName());
 System.out.println(list.item(0).getNodeValue());

我明白了

null
#text

代替“title”和“bigfish live 200812”

我做错了什么？谢谢

<?xml version="1.0" encoding="utf-8" ?> 
<rsp stat="ok"> 
<photo id="2882550369" secret="21054282c8" server="3106" farm="4" dateuploaded="1222202793" isfavorite="0" license="0" safety_level="0" rotation="0" views="5" media="photo"> 
    <owner nsid="64878451@N00" username="fishthemusic" realname="masayoshi yamamiya" location="kawasaki, japan" iconserver="4" iconfarm="1" /> 
    <title>bigfish live 200812</title> 
    <description>photo by Kazuhiro Nakamura</description> 
    <visibility ispublic="1" isfriend="0" isfamily="0" /> 
    <dates posted="1222202793" taken="2008-09-24 05:46:33" takengranularity="0" lastupdate="1222998937" /> 
    <editability cancomment="1" canaddmeta="0" /> 
    <publiceditability cancomment="1" canaddmeta="0" /> 
    <usage candownload="1" canblog="1" canprint="0" canshare="1" /> 
    <comments>0</comments> 
    <notes /> 
    <tags> 
        <tag id="314160-2882550369-80673" author="64878451@N00" raw="bigfish" machine_tag="0">bigfish</tag> 
        <tag id="314160-2882550369-5558" author="64878451@N00" raw="live" machine_tag="0">live</tag> 
        <tag id="314160-2882550369-29726586" author="64878451@N00" raw="upcoming:event=1167424" machine_tag="1">upcoming:event=1167424</tag> 
    </tags> 
    <urls> 
        <url type="photopage">http://www.flickr.com/photos/fishthemusic/2882550369/</url> 
    </urls> 
</photo> 
</rsp>

Answer 1

photo 元素中有文本节点，在下面的示例中标记为 XXXX。您将获得此文本节点。请注意，可能有多个相邻的文本节点。您需要找到第一个具有 Element 类型的节点才能获取您的 owner 元素。

<photo ...>XXXX 
XXXX<owner nsid="64878451@N00" ... /> 

试试这个:

NodeList list = doc.getElementsByTagName("photo");
element = (Element)list.item(0);
list = element.getChildNodes();

int ix = 0;
while (ix < list.getLength() && list.item(ix).getNodeType() != Node.ELEMENT_NODE) {
  ix++;
}

// now ix points to your first element node (if there was one)

System.out.println(list.item(ix).getNodeName());
System.out.println(list.item(ix).getNodeValue());

顺便说一句，元素的“nodeValue”是null，所以你应该看到

owner
null

作为输出。另见 http://download.oracle.com/javase/6/docs/api/org/w3c/dom/Node.html了解详情。 (它还表明 #text 是文本节点的 nodeName，正是您得到的)。