java - XML 模式验证时超时和挂起线程

Question

我在通过 XSD 架构验证 XML 时收到 TimeoutException，并且与检查器关联的线程被挂起。

为什么会这样呢？如何避免这种情况？

堆栈跟踪:

TimeoutManage I   WTRN0124I: When the timeout occurred the thread with which the transaction is, or was most recently, associated was Thread[WebContainer : 3,5,main].  The stack trace of this thread when the timeout occurred was:
        java.net.SocketInputStream.socketRead0(Native Method)
        java.net.SocketInputStream.read(SocketInputStream.java:140)
        java.io.BufferedInputStream.fill(BufferedInputStream.java:229)
        java.io.BufferedInputStream.read1(BufferedInputStream.java:269)
        java.io.BufferedInputStream.read(BufferedInputStream.java:328)
        sun.net.www.http.HttpClient.parseHTTPHeader(HttpClient.java:700)
        sun.net.www.http.HttpClient.parseHTTP(HttpClient.java:645)
        sun.net.www.protocol.http.HttpURLConnection.getInputStream(HttpURLConnection.java:1205)
        org.apache.xerces.impl.XMLEntityManager.setupCurrentEntity(Unknown Source)
        org.apache.xerces.impl.XMLVersionDetector.determineDocVersion(Unknown Source)
        org.apache.xerces.impl.xs.opti.SchemaParsingConfig.parse(Unknown Source)
        org.apache.xerces.impl.xs.opti.SchemaParsingConfig.parse(Unknown Source)
        org.apache.xerces.impl.xs.opti.SchemaDOMParser.parse(Unknown Source)
        org.apache.xerces.impl.xs.traversers.XSDHandler.getSchemaDocument(Unknown Source)
        org.apache.xerces.impl.xs.traversers.XSDHandler.resolveSchema(Unknown Source)
        org.apache.xerces.impl.xs.traversers.XSDHandler.constructTrees(Unknown Source)
        org.apache.xerces.impl.xs.traversers.XSDHandler.parseSchema(Unknown Source)
        org.apache.xerces.impl.xs.XMLSchemaLoader.loadSchema(Unknown Source)
        org.apache.xerces.impl.xs.XMLSchemaLoader.loadGrammar(Unknown Source)
        org.apache.xerces.impl.xs.XMLSchemaLoader.loadGrammar(Unknown Source)
        org.apache.xerces.jaxp.validation.XMLSchemaFactory.newSchema(Unknown Source)
        javax.xml.validation.SchemaFactory.newSchema(Unknown Source)
        my.utils.XmlUtils.validate(XmlUtils.java:38)

用于验证的代码片段:

SchemaFactory schemaFactory = 
    SchemaFactory.newInstance(XMLConstants.W3C_XML_SCHEMA_NS_URI);
try {
    Schema schema = schemaFactory.newSchema(new StreamSource(new StringReader(xsd)));
    Validator validator = schema.newValidator();
...

异常发生在行:

Schema schema = schemaFactory.newSchema(new StreamSource(new StringReader(xsd)));

Answer 1

如果没有看到实际的 XSD，很难确定，但很可能您的架构不是自包含的，而是包含一个或多个引用外部 URL 的 include 语句。 schemaFactory 可能会尝试获取它们来构建完整的 XSD。

指出这一点的原因之一是堆栈跟踪中对 getSchemaDocument() 的调用，该调用试图在执行 parseSchema()< 的过程中通过 HTTP 获取架构文档 您传入的 xsd 上。