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问题描述
我有如下所示的 xml 文档:
I have xml documents that look like this:
<?xml version="1.0"?>
<root>
<success>true</success>
<note>
<note_id>32219</note_id>
<the_date>1336763490</the_date>
<member_id>108649</member_id>
<area>6</area>
<note>Note 123123123</note>
</note>
<note>
<note_id>33734</note_id>
<the_date>1339003652</the_date>
<member_id>108649</member_id>
<area>1</area>
<note>This is another note.</note>
</note>
<note>
<note_id>49617</note_id>
<the_date>1343050791</the_date>
<member_id>108649</member_id>
<area>1</area>
<note>this is a 3rd note.</note>
</note>
</root>
我想获取该文档，并获取所有 标记并将它们转换为字符串，然后将它们传递给我的 XML 类并将 XML 类放入一个数组中列表.我希望这是有道理的.所以这是我试图用来获取所有 <note> 标签的方法.
I would like to take that document, and get all of the <note> tags and convert them to a string, then pass them to my XML class and place the XML class into an array list. I hope that makes sense. So Here is the method that I am trying to use to get all of the <note> tags.
public ArrayList<XML> getNodes(String root, String name){
ArrayList<XML> elList = new ArrayList<>();
NodeList nodes = doc.getElementsByTagName(root);
for(int i = 0; i < nodes.getLength(); i++){
Element element = (Element)nodes.item(i);
NodeList nl = element.getElementsByTagName(name);
for(int c = 0; c < nl.getLength(); c++){
Element e = (Element)nl.item(c);
String xmlStr = this.nodeToString(e);
XML xml = new XML();
xml.parse(xmlStr);
elList.add(xml);
}
}
return elList;
}
private String nodeToString(Node node){
StringWriter sw = new StringWriter();
try{
Transformer t = TransformerFactory.newInstance().newTransformer();
t.setOutputProperty(OutputKeys.OMIT_XML_DECLARATION, "yes");
t.transform(new DOMSource(node), new StreamResult(sw));
}catch(TransformerException te){
System.out.println("nodeToString Transformer Exception");
}
return sw.toString();
}
所以，我的问题是，如何将每个 标记作为字符串获取?使用我现在拥有的代码，我返回的是 null for String xmlStr = e.getNodeValue();.
So, my question is, how can I get each <note> tag as a string? With the code I have now all I get back is null for String xmlStr = e.getNodeValue();.
编辑
我编辑了我的主要代码，这似乎有效.
Edit
I edited my main code, this seems to work.
推荐答案
澄清后更新
您可以使用 XPath 找到所有 元素.
You can find all the <note> elements using XPath.
这将允许您简单地隔离每个节点.然后，您可以根据找到的节点创建一个新文档并将其转换回字符串
This will allow you to isolate each node simply. You can then create a new document, based on the found nodes and transform it back to string
public class TestXML01 {
public static void main(String[] args) {
String xml = "<?xml version=\"1.0\"?>";
xml += "<root>";
xml += "<success>true</success>";
xml += "<note>";
xml += "<note_id>32219</note_id>";
xml += "<the_date>1336763490</the_date>";
xml += "<member_id>108649</member_id>";
xml += "<area>6</area>";
xml += "<note>Note 123123123</note>";
xml += "</note>";
xml += "<note>";
xml += "<note_id>33734</note_id>";
xml += "<the_date>1339003652</the_date>";
xml += "<member_id>108649</member_id>";
xml += "<area>1</area>";
xml += "<note>This is another note.</note>";
xml += "</note>";
xml += "<note>";
xml += "<note_id>49617</note_id>";
xml += "<the_date>1343050791</the_date>";
xml += "<member_id>108649</member_id>";
xml += "<area>1</area>";
xml += "<note>this is a 3rd note.</note>";
xml += "</note>";
xml += "</root>";
ByteArrayInputStream bais = null;
try {
bais = new ByteArrayInputStream(xml.getBytes());
DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
factory.setNamespaceAware(false);
DocumentBuilder builder = factory.newDocumentBuilder();
Document xmlDoc = builder.parse(bais);
Node root = xmlDoc.getDocumentElement();
XPathFactory xFactory = XPathFactory.newInstance();
XPath xPath = xFactory.newXPath();
XPathExpression xExpress = xPath.compile("/root/note");
NodeList nodes = (NodeList) xExpress.evaluate(root, XPathConstants.NODESET);
System.out.println("Found " + nodes.getLength() + " note nodes");
for (int index = 0; index < nodes.getLength(); index++) {
Node node = nodes.item(index);
Document childDoc = builder.newDocument();
childDoc.adoptNode(node);
childDoc.appendChild(node);
System.out.println(toString(childDoc));
}
} catch (Exception exp) {
exp.printStackTrace();
} finally {
try {
bais.close();
} catch (Exception e) {
}
}
}
public static String toString(Document doc) {
String sValue = null;
ByteArrayOutputStream baos = null;
OutputStreamWriter osw = null;
try {
baos = new ByteArrayOutputStream();
osw = new OutputStreamWriter(baos);
Transformer tf = TransformerFactory.newInstance().newTransformer();
tf.setOutputProperty(OutputKeys.INDENT, "yes");
tf.setOutputProperty(OutputKeys.METHOD, "xml");
tf.setOutputProperty("{http://xml.apache.org/xslt}indent-amount", "4");
DOMSource domSource = new DOMSource(doc);
StreamResult sr = new StreamResult(osw);
tf.transform(domSource, sr);
osw.flush();
baos.flush();
sValue = new String(baos.toByteArray());
} catch (Exception exp) {
exp.printStackTrace();
} finally {
try {
osw.close();
} catch (Exception exp) {
}
try {
baos.close();
} catch (Exception exp) {
}
}
return sValue;
}
}
现在输出...
Found 3 note nodes
<?xml version="1.0" encoding="UTF-8" standalone="no"?>
<note>
<note_id>32219</note_id>
<the_date>1336763490</the_date>
<member_id>108649</member_id>
<area>6</area>
<note>Note 123123123</note>
</note>
<?xml version="1.0" encoding="UTF-8" standalone="no"?>
<note>
<note_id>33734</note_id>
<the_date>1339003652</the_date>
<member_id>108649</member_id>
<area>1</area>
<note>This is another note.</note>
</note>
<?xml version="1.0" encoding="UTF-8" standalone="no"?>
<note>
<note_id>49617</note_id>
<the_date>1343050791</the_date>
<member_id>108649</member_id>
<area>1</area>
<note>this is a 3rd note.</note>
</note>
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