java builder.parse((new StringReader(xml)) 返回 DeferredDocumentImpl
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builder.parse((new StringReader(xml)) returns DeferredDocumentImpl
提问by user393381
I am trying to understand what mistake I could have made but can't find the solution.
我试图了解我可能犯了什么错误但找不到解决方案。
public static Document getXMLFromString(String xml) {
org.w3c.dom.Document doc = null;
try {
DocumentBuilderFactory factory = DocumentBuilderFactory
.newInstance();
factory.setNamespaceAware(true);
DocumentBuilder builder;
builder = factory.newDocumentBuilder();
doc = (org.w3c.dom.Document) builder.parse(new InputSource(
new StringReader(xml)));
} catch (SAXException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
} catch (ParserConfigurationException e) {
e.printStackTrace();
}
return doc;
}
I did import org.w3c.dom.Document
我确实导入了 org.w3c.dom.Document
I am calling this method here:
我在这里调用这个方法：
private Node getAuthToken(SOAPMessage responseAuth) throws SOAPException,
TransformerException, ParserConfigurationException, IOException,
SAXException {
String s = indentXML(responseAuth.getSOAPPart().getContent());
Document doc = getXMLFromString(s);
NodeList authTokenNodeList = doc.getElementsByTagName("authToken");
return authTokenNodeList.item(0);
}
The NodeList is empty.
NodeList 是空的。
After researching on the web, everybody uses this code to parse a string to a Document. I do not have any exception but after calling the method parse(), the value of doc is set to [#document: null] DeferredDocumentImpl.
网上查了下，大家都是用这段代码把一个字符串解析成一个Document的。我没有任何异常，但是在调用方法 parse() 之后，doc 的值被设置为 [#document: null] DeferredDocumentImpl。
I am using everything from the org.w3c.dom.
我正在使用 org.w3c.dom 中的所有内容。
xml is a string that contains
xml 是一个字符串，包含
<?xml version="1.0" encoding="UTF-8"?>
<soap:Envelope xmlns:soap="http://schemas.xmlsoap.org/soap/envelope/">
<soap:Header>
<context xmlns="urn:zimbra">
<session id="36" type="admin">36</session>
<change token="251"/>
</context>
</soap:Header>
<soap:Body>
<AuthResponse xmlns="urn:zimbraAdmin">
<authToken>...</authToken>
<lifetime>...</lifetime>
<a n="zimbraIsDomainAdminAccount">false</a>
<session id="36" type="admin">36</session>
</AuthResponse>
</soap:Body>
</soap:Envelope>
Here is how I built the string after a SOAP call:
以下是我在 SOAP 调用后构建字符串的方式：
String xml = indentXML(responseAuth.getSOAPPart().getContent());
What am I doing wrong?
我究竟做错了什么？
This is what I am trying to do in a simple way:
这就是我试图以一种简单的方式做的事情：
StringBuilder soapResponse = new StringBuilder(...
...
...
);
org.w3c.dom.Document doc = null;
try {
DocumentBuilderFactory factory = DocumentBuilderFactory
.newInstance();
factory.setNamespaceAware(true);
DocumentBuilder builder;
builder = factory.newDocumentBuilder();
doc = (org.w3c.dom.Document) builder.parse(new InputSource(
new StringReader(soapResponse.toString())));
} catch (SAXException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
} catch (ParserConfigurationException e) {
e.printStackTrace();
}
NodeList authTokenNodeList = doc.getElementsByTagName("authToken");
Node n = authTokenNodeList.item(0);
String s = n.getNodeValue();
回答by Jon Skeet
EDIT: Looking at your updated code, I think this is the problem:
编辑：查看您更新的代码，我认为这是问题所在：
String s = n.getNodeValue();
If you look at the docs for Nodeyou'll see that getNodeValue()is defined to return nullfor elements... hence the problem. My sample code uses getTextContent()instead, which works fine.
如果您查看Node的文档，您会看到它getNodeValue()被定义为返回null元素……因此是问题所在。我的示例代码getTextContent()改为使用，效果很好。
It looks like that's just going to defer expanding in-memory objects until they're required.
看起来这只会推迟扩展内存中的对象，直到需要它们为止。
Have you tried calling methods on the returned document rather than just looking in the debugger? I suspect everything is actually working as intended. If not, please post a short but completeprogram which shows it misbehaving. (Note that in the sample you've given, you haven't even shown how builderis set, and you haven't used factory.)
您是否尝试过在返回的文档上调用方法，而不仅仅是在调试器中查看？我怀疑一切实际上都按预期工作。如果没有，请发布一个简短但完整的程序，以显示其行为不端。（请注意，在您提供的示例中，您甚至没有显示如何builder设置，也没有使用factory.）
EDIT: The code you've given works for me. Here's a quick-and-dirty - but importantly, complete- program (using Guavato load the XML file into a string) which shows the node being found successfully:
编辑：您提供的代码对我有用。这是一个快速但重要的完整程序（使用Guava将 XML 文件加载到字符串中），它显示已成功找到节点：
import org.w3c.dom.*;
import org.xml.sax.*;
import java.text.*;
import java.util.*;
import javax.xml.parsers.*;
import java.io.*;
import com.google.common.base.*;
import com.google.common.io.*;
public class Test {
public static void main(String[] args) throws Exception {
String xml = Files.toString(new File("test.xml"), Charsets.UTF_8);
Node node = getAuthToken(xml);
System.out.println(node.getTextContent());
}
private static Node getAuthToken(String xml) throws Exception {
Document doc = getXMLFromString(xml);
NodeList authTokenNodeList = doc.getElementsByTagName("authToken");
return authTokenNodeList.item(0);
}
public static Document getXMLFromString(String xml) throws Exception {
Document doc = null;
DocumentBuilderFactory factory = DocumentBuilderFactory
.newInstance();
factory.setNamespaceAware(true);
DocumentBuilder builder;
builder = factory.newDocumentBuilder();
doc = builder.parse(new InputSource(new StringReader(xml)));
return doc;
}
}
