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POXpath memory leak?
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  1. POXpath memory leak?
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    copied!<p>There appears to be a memory leak when using the standard Java library (1.6.0_27) for evaluating XPath expressions.</p> <p>See below for some code to reproduct this problem:</p> <pre><code>public class XpathTest { public static void main(String[] args) throws Exception { DocumentBuilderFactory docFactory = DocumentBuilderFactory.newInstance(); docFactory.setNamespaceAware(true); DocumentBuilder builder = docFactory.newDocumentBuilder(); Document doc = builder.parse("test.xml"); XPathFactory factory = XPathFactory.newInstance(); XPath xpath = factory.newXPath(); XPathExpression expr = xpath.compile("//Product"); Object result = expr.evaluate(doc, XPathConstants.NODESET); NodeList nodes = (NodeList) result; for (int i = 0; i &lt; nodes.getLength(); i++) { Node node = nodes.item(i); System.out.println(node.getAttributes().getNamedItem("id")); XPathExpression testExpr = xpath.compile("Test"); Object testResult = testExpr.evaluate(node, XPathConstants.NODE); Node test = (Node) testResult; System.out.println(test.getTextContent()); } System.out.println(nodes.getLength()); } } </code></pre> <p>An example XML file is given below:</p> <pre><code>&lt;Products&gt; &lt;Product id='ID0'&gt; &lt;Test&gt;0&lt;/Test&gt; &lt;/Product&gt; &lt;Product id='ID1'&gt; &lt;Test&gt;1&lt;/Test&gt; &lt;/Product&gt; &lt;Product id='ID2'&gt; &lt;Test&gt;2&lt;/Test&gt; &lt;/Product&gt; &lt;Product id='ID3'&gt; &lt;Test&gt;3&lt;/Test&gt; &lt;/Product&gt; ... &lt;/Products&gt; </code></pre> <p>When I run this example using the NetBeans profiler it appears that the allocations for the com.sun.org.apache.xpath.internal.objects.XObject class keeps increasing, even after garbage collection.</p> <p>Am I using the XPath library in an incorrect way? Is this a bug in the Java libraries? Are there are potential workarounds?</p>
 

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