java - 尝试解析 XML 字符串时没有向我抛出协议(protocol)格式错误的 URL 异常

Question

当尝试解析 XML 字符串时，我收到一个格式错误的 URL 异常。

这是堆栈跟踪:

java.net.MalformedURLException: no protocol: <explanation>
<NodeExplanations>
    <IDAfterSkipProcessing>/Temporary/isMfs</IDAfterSkipProcessing>
    <NodeExplanation>
        <ID>/Temporary/isMfs</ID>
        <SkippedToIDForExplanationData>/Temporary/isMfs</SkippedToIDForExplanationData>
        <Value>false</Value>
        <Gist>Equals</Gist>
        <Scenario>NOT_EQUAL</Scenario>
        <Title>IsMfs</Title>
        <Phrase>
            <Text>isMfs</Text>
        </Phrase>
        <Question>
            <Text>isMfs</Text>
        </Question>
        <ExplanationText>
            <Text>We can't get any more details on </Text>
            <NodeName>
                <Text>isMfs</Text>
            </NodeName>
            <Text> right now.</Text>
        </ExplanationText>
        <InputNodes>
            <InputNodeEntry>
                <ID>/Return/ReturnData/IRS1040/IndividualReturnFilingStatusCd</ID>
                <Role>Value</Role>
                <Value>2</Value>
                <Type>CALCULATED_NODE</Type>
                <HasSubExplanations>false</HasSubExplanations>
            </InputNodeEntry>
            <InputNodeEntry>
                <ID>/Constants/IRS1040/FilingStatus/MarriedFilingSeparatelyCd</ID>
                <Role>Value</Role>
                <Value>3</Value>
                <Type>CONSTANT_NODE</Type>
                <HasSubExplanations>false</HasSubExplanations>
            </InputNodeEntry>
        </InputNodes>
        <Children>
            <ID>/Return/ReturnData/IRS1040/IndividualReturnFilingStatusCd</ID>
        </Children>
    </NodeExplanation>
</NodeExplanations>
</explanation>

    at java.net.URL.<init>(URL.java:585)
    at java.net.URL.<init>(URL.java:482)
    at java.net.URL.<init>(URL.java:431)
    at org.apache.xerces.impl.XMLEntityManager.setupCurrentEntity(Unknown Source)
    at org.apache.xerces.impl.XMLVersionDetector.determineDocVersion(Unknown Source)
    at org.apache.xerces.parsers.XML11Configuration.parse(Unknown Source)
    at org.apache.xerces.parsers.XML11Configuration.parse(Unknown Source)
    at org.apache.xerces.parsers.XMLParser.parse(Unknown Source)
    at org.apache.xerces.parsers.DOMParser.parse(Unknown Source)
    at org.apache.xerces.jaxp.DocumentBuilderImpl.parse(Unknown Source)
    at javax.xml.parsers.DocumentBuilder.parse(DocumentBuilder.java:177)

我不知道为什么，XML 绝对有效并且没有格式错误？

这是进行解析的代码:

static Document getDocument(String xml) throws FileNotFoundException {

    DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance();
    DocumentBuilder db;
    Document doc = null;

    try {
        db = dbf.newDocumentBuilder();
        doc = db.parse(xml);
        doc.getDocumentElement().normalize();
    } 
    catch (ParserConfigurationException e) {
        e.printStackTrace();
    } catch (IOException e) {
        e.printStackTrace();
    } catch (SAXException e) {
        e.printStackTrace();
    }
    return doc;
}

是什么原因造成的以及如何修复它？任何帮助或协助将不胜感激，谢谢。

Answer 1

DocumentBuilder.parse(String) 方法需要 URI，然后该方法会尝试打开该 URI。如果您想直接传递字符串的内容，则必须将其作为输入流提供。

DocumentBuilder db = ...;
String xml = ...;
db.parse(new InputSource(new ByteArrayInputStream(xml.getBytes("utf-8"))));

此文档可能会有所帮助 http://docs.oracle.com/javase/1.5.0/docs/api/javax/xml/parsers/DocumentBuilder.html