dom4j中使用xpath解析带命名空间的xml文件,取不到节点的解决办法 (转载)-优快云博客

本文链接：https://blog.youkuaiyun.com/tempdowncomputer/article/details/84188355

本文通过一个具体的XML示例，展示了如何使用XPath进行元素定位及查询，并对比了不同XPath表达式的有效性，为开发者提供了一个实践性的参考案例。

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<?xml version="1.0" encoding="gbk" standalone="yes"?>
<unit xmlns="http://www.sdml.info/srcML/src" xmlns:cpp="http://www.sdml.info/srcML/cpp">
    <cpp:ifndef>
        <name>test</name>
    </cpp:ifndef>
    <class>class</class>
</unit>

转载之 http://blog.youkuaiyun.com/fm2005/article/details/4074313

    public static void main(String [] args){  
                Document document = XmlTools.getDoc(file.getPath());  
                HashMap xmlMap = new HashMap();  
                xmlMap.put("src", "http://www.sdml.info/srcML/src");  
                xmlMap.put("cpp", "http://www.sdml.info/srcML/cpp");  
                // 以下可以访问到  
                XPath x0 = document.createXPath("unit/src:class");  
                XPath x1 = document.createXPath("src:unit/src:class");  
                XPath x2 = document.createXPath("/unit/src:class");  
                XPath x3 = document.createXPath("unit/src:class");  
                XPath x4 = document.createXPath("/unit/cpp:define");  
                XPath x6 = document.createXPath("unit/cpp:define");  
                XPath x7 = document.createXPath("src:unit/cpp:define");  
                // 以下访问不到  
                XPath x8 = document.createXPath("unit/class");  
                XPath x9 = document.createXPath("unit/define");  
                XPath x10 = document.createXPath("/unit/class");  
                XPath x11 = document.createXPath("/unit/define");  
                XPath x12 = document.createXPath("src:unit/class");  
                XPath x13 = document.createXPath("src:unit/define");  
                XPath x14 = document.createXPath("unit/cpp:class");  
                XPath x15 = document.createXPath("unit/src:define");  
                test(x0, document, xmlMap);  
                test(x1, document, xmlMap);  
                test(x2, document, xmlMap);  
                test(x3, document, xmlMap);  
                test(x4, document, xmlMap);  
                test(x6, document, xmlMap);  
                test(x7, document, xmlMap);  
                test(x8, document, xmlMap);  
                test(x9, document, xmlMap);  
                test(x10, document, xmlMap);  
                test(x11, document, xmlMap);  
                test(x12, document, xmlMap);  
                test(x13, document, xmlMap);  
                test(x14, document, xmlMap);  
                test(x15, document, xmlMap);  
    }  
        static void test(XPath x, Document doc, Map map) {  
            x.setNamespaceURIs(map);  
            System.out.println("运行结果:"+x.selectNodes(doc).size());  
        }

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