Java应用程序FreeMind使用XSLT更新旧文件。XSLT使用静态java函数简化字符串操作。这在Java 7更新2之前都运行良好,并在Windows下的Java 7更新4中给出以下异常:
STDERR: ERROR: 'The first argument to the non-static Java function 'replaceSpacesToNonbreakableSpaces' is not a valid object reference.'
STDERR: FATAL ERROR: 'Could not compile stylesheet'May 26, 2012 10:50:06 PM freemind.main.Resources logException
SEVERE: An exception occured:
javax.xml.transform.TransformerConfigurationException: Could not compile stylesheet
at com.sun.org.apache.xalan.internal.xsltc.trax.TransformerFactoryImpl.newTemplates(Unknown Source)
at com.sun.org.apache.xalan.internal.xsltc.trax.TransformerFactoryImpl.newTransformer(Unknown Source)
at freemind.main.Tools$1TransformerRunnable.run(Tools.java:1023)
at java.lang.Thread.run(Unknown Source)
将问题简化后,发现原因是自定义的SecurityManager造成了问题。如果设定了自定义SecurityManager,则代码会失败;如果将其注释掉,则代码可以正常工作。有人知道java7中2号和4号更新之间的安全系统发生了什么变化,或者还有什么其他可能引起该问题的原因吗?
以下是更为简单的示例:
package freemind.main;
import java.io.StringReader;
import java.io.StringWriter;
import javax.xml.transform.Result;
import javax.xml.transform.Transformer;
import javax.xml.transform.TransformerFactory;
import javax.xml.transform.stream.StreamResult;
import javax.xml.transform.stream.StreamSource;
public final class FreeMindSecurityTest {
public static void main(String[] args) throws Exception {
// if commented out, this program works as expected.
System.setSecurityManager(new SecurityManager());
String input = "<map version=\"0.9.0\">"
+ "</map>";
String xslt = "<?xml version=\"1.0\" encoding=\"UTF-8\"?>"
+ " <xsl:stylesheet version=\"1.0\" xmlns:xsl=\"http://www.w3.org/1999/XSL/Transform\" xmlns:FreeMindSecurityTest=\"xalan://freemind.main.FreeMindSecurityTest\" exclude-result-prefixes=\"FreeMindSecurityTest\">"
+ " <xsl:template match=\"/ | node() | @* | comment() | processing-instruction()\">"
+ " <xsl:value-of select=\"FreeMindSecurityTest:replaceSpacesToNonbreakableSpaces('test')\"/>"
+ " </xsl:template>" + " </xsl:stylesheet>";
StringWriter writer = new StringWriter();
final Result result = new StreamResult(writer);
final StreamSource sr = new StreamSource(new StringReader(input));
// create an instance of TransformerFactory
TransformerFactory transFact = TransformerFactory.newInstance();
Transformer trans = transFact.newTransformer(new StreamSource(
new StringReader(xslt)));
trans.transform(sr, result);
System.out.println("Transformed: " + writer.getBuffer());
writer.close();
}
public static String replaceSpacesToNonbreakableSpaces(String input) {
return input;
}
}
简而言之,Java认为该方法不是静态的(但实际上是静态的),并且缺少对象引用。
谢谢,来自FreeMind的Chris
编辑:添加了最短的示例(只需设置普通安全管理器的副本即可)。
SecurityManager
也会导致此XSLT转换失败。 - Chris from FreeMind