带有Saxon的Apache Camel Xpath 2.0在RouteBuilder/谓词中看起来不起作用

我使用的是ServiceMix 4.5.3，其中包括Camel 2.10.7，并且我能够使用以下端点选项对Saxon库进行XSLT 2.0转换：

...
to("xslt:stylesheet.xsl?transformerFactoryClass=net.sf.saxon.TransformerFactoryImpl")
...

private Namespaces ourNS = new Namespaces("myns",
        "urn:com:company:domain:namespace:myns/1");

// ... some code ...

// Make a predicate to filter according a header : 
// The code attribute looks like: urn:phone:apple:iphone:4s
Predicate isNotSamePhoneBrand = PredicateBuilder.isNotEqualTo(
        xpath("tokenize(/myns:Phone/@code, ':')[3]").namespaces(ourNS),
        header("PhoneBrand"));

.factory(new net.sf.saxon.xpath.XPathFactoryImpl())

Predicate isNotSamePhoneBrand = PredicateBuilder.isNotEqualTo(
        xpath("tokenize(/myns:Phone/@code, ':')[3]").namespaces(ourNS)
        .factory(new net.sf.saxon.xpath.XPathFactoryImpl()).resultType(String.class),
        header("PhoneBrand"));

net.sf.saxon.xpath.XPathFactoryImpl factory = new net.sf.saxon.xpath.XPathFactoryImpl();
XPath xpath = factory.newXPath();

NodeList channels = (NodeList) xpath.evaluate(
    "//*:Channels/*:Channel/text()",
    body, XPathConstants.NODESET);

但是，当我尝试像这样使用xpath函数时：

...
to("xslt:stylesheet.xsl?transformerFactoryClass=net.sf.saxon.TransformerFactoryImpl")
...

private Namespaces ourNS = new Namespaces("myns",
        "urn:com:company:domain:namespace:myns/1");

// ... some code ...

// Make a predicate to filter according a header : 
// The code attribute looks like: urn:phone:apple:iphone:4s
Predicate isNotSamePhoneBrand = PredicateBuilder.isNotEqualTo(
        xpath("tokenize(/myns:Phone/@code, ':')[3]").namespaces(ourNS),
        header("PhoneBrand"));

.factory(new net.sf.saxon.xpath.XPathFactoryImpl())

Predicate isNotSamePhoneBrand = PredicateBuilder.isNotEqualTo(
        xpath("tokenize(/myns:Phone/@code, ':')[3]").namespaces(ourNS)
        .factory(new net.sf.saxon.xpath.XPathFactoryImpl()).resultType(String.class),
        header("PhoneBrand"));

net.sf.saxon.xpath.XPathFactoryImpl factory = new net.sf.saxon.xpath.XPathFactoryImpl();
XPath xpath = factory.newXPath();

NodeList channels = (NodeList) xpath.evaluate(
    "//*:Channels/*:Channel/text()",
    body, XPathConstants.NODESET);

如果我执行上面的代码，它会说tokenize函数是未知的。我想这是因为它仍然使用XalanXPath1.0而不是Saxon

我还尝试在Camel文档中添加.saxon

Predicate isNotSamePhoneBrand = PredicateBuilder.isNotEqualTo(
        xpath("tokenize(/myns:Phone/@code, ':')[3]").namespaces(ourNS).saxon(),
        header("PhoneBrand"));

但他无法找到Saxon实现工厂，这是一个错误：

Caused by: javax.xml.xpath.XPathFactoryConfigurationException: No XPathFctory implementation found for the object model: http://saxon.sf.net/jaxp/xpath/om

在我的OSGI上下文中，我验证了camel-saxon和ApacheServiceMix:：Bundles:：saxon9he 9.3.0.112都已部署

---

我们计划很快升级到ServiceMix 5，但我不知道这个问题是否仍然存在，4.5.3版的解决方案对我来说会更好。

在Saxon 9.6中，我们删除了将Saxon注册为JAXP XPathFactory接口实现的服务文件。它仍然实现该接口，只是在JAR文件清单中没有这样的服务文件。这背后有很长的历史，但基本上有两个主要原因：JDK版本之间的不兼容导致无法生成从JDK 5到JDK 8（包括JDK 5到JDK 8）的服务文件；b仅仅将Saxon放在类路径上会导致应用程序在未编写或测试以使用XPath 2.0的情况下崩溃

---

我想，通过将服务文件添加到SAXON Jar文件清单，您可以自己复制9.5版本中的服务文件，这是一个解决方案。

最后，我找到了一个骆驼路线的有效解决方案：

由于.saxon对我的路径没有影响，我决定换一种方式看，我发现有一个特定的选项可以覆盖Xpath工厂，如下所示：

...
to("xslt:stylesheet.xsl?transformerFactoryClass=net.sf.saxon.TransformerFactoryImpl")
...

private Namespaces ourNS = new Namespaces("myns",
        "urn:com:company:domain:namespace:myns/1");

// ... some code ...

// Make a predicate to filter according a header : 
// The code attribute looks like: urn:phone:apple:iphone:4s
Predicate isNotSamePhoneBrand = PredicateBuilder.isNotEqualTo(
        xpath("tokenize(/myns:Phone/@code, ':')[3]").namespaces(ourNS),
        header("PhoneBrand"));

.factory(new net.sf.saxon.xpath.XPathFactoryImpl())

Predicate isNotSamePhoneBrand = PredicateBuilder.isNotEqualTo(
        xpath("tokenize(/myns:Phone/@code, ':')[3]").namespaces(ourNS)
        .factory(new net.sf.saxon.xpath.XPathFactoryImpl()).resultType(String.class),
        header("PhoneBrand"));

net.sf.saxon.xpath.XPathFactoryImpl factory = new net.sf.saxon.xpath.XPathFactoryImpl();
XPath xpath = factory.newXPath();

NodeList channels = (NodeList) xpath.evaluate(
    "//*:Channels/*:Channel/text()",
    body, XPathConstants.NODESET);

之后，我必须强制将Xpath的结果转换为带有.resultTypeString.class的字符串

完整谓词如下所示：

...
to("xslt:stylesheet.xsl?transformerFactoryClass=net.sf.saxon.TransformerFactoryImpl")
...

private Namespaces ourNS = new Namespaces("myns",
        "urn:com:company:domain:namespace:myns/1");

// ... some code ...

// Make a predicate to filter according a header : 
// The code attribute looks like: urn:phone:apple:iphone:4s
Predicate isNotSamePhoneBrand = PredicateBuilder.isNotEqualTo(
        xpath("tokenize(/myns:Phone/@code, ':')[3]").namespaces(ourNS),
        header("PhoneBrand"));

.factory(new net.sf.saxon.xpath.XPathFactoryImpl())

Predicate isNotSamePhoneBrand = PredicateBuilder.isNotEqualTo(
        xpath("tokenize(/myns:Phone/@code, ':')[3]").namespaces(ourNS)
        .factory(new net.sf.saxon.xpath.XPathFactoryImpl()).resultType(String.class),
        header("PhoneBrand"));

net.sf.saxon.xpath.XPathFactoryImpl factory = new net.sf.saxon.xpath.XPathFactoryImpl();
XPath xpath = factory.newXPath();

NodeList channels = (NodeList) xpath.evaluate(
    "//*:Channels/*:Channel/text()",
    body, XPathConstants.NODESET);

现在，标记化函数xpath 2.0已经得到了很好的认可

我发现在骆驼处理器中使用工厂实现时，我必须对工厂实现的实例化做同样的事情，如下所示：

...
to("xslt:stylesheet.xsl?transformerFactoryClass=net.sf.saxon.TransformerFactoryImpl")
...

private Namespaces ourNS = new Namespaces("myns",
        "urn:com:company:domain:namespace:myns/1");

// ... some code ...

// Make a predicate to filter according a header : 
// The code attribute looks like: urn:phone:apple:iphone:4s
Predicate isNotSamePhoneBrand = PredicateBuilder.isNotEqualTo(
        xpath("tokenize(/myns:Phone/@code, ':')[3]").namespaces(ourNS),
        header("PhoneBrand"));

.factory(new net.sf.saxon.xpath.XPathFactoryImpl())

Predicate isNotSamePhoneBrand = PredicateBuilder.isNotEqualTo(
        xpath("tokenize(/myns:Phone/@code, ':')[3]").namespaces(ourNS)
        .factory(new net.sf.saxon.xpath.XPathFactoryImpl()).resultType(String.class),
        header("PhoneBrand"));

net.sf.saxon.xpath.XPathFactoryImpl factory = new net.sf.saxon.xpath.XPathFactoryImpl();
XPath xpath = factory.newXPath();

NodeList channels = (NodeList) xpath.evaluate(
    "//*:Channels/*:Channel/text()",
    body, XPathConstants.NODESET);

---

这不是动态的，但我想在任何地方强制使用Saxon，这样这个解决方案就符合我们的需要。

Ok，那么它看起来更像是JVM的类路径问题，而不是ServiceMix中的特定问题。这就解释了为什么有时候它可以在JUnitEclipseJVM中工作，而不能在集成测试SMXJVM中工作。我会找到一个解决方案，但还不确定它是否有效。啊，请注意你所说的版本。但我认为我们有在SMX控制台中编写的9.3.0.112。正如您所说，我们应该能够使用9.6之前的服务。但它似乎不能按原样工作。您使用的JDK版本是什么？众所周知，我们以前包含的服务文件与JDK 8不兼容。我们在centos 6.5下使用JDK 7 me，在windows 7下使用我的同事。。。但两个平台上的效果相同谢谢你的帖子，它帮助我找到合适的解决方案，看看我的答案