[xsl-fo转换使用Java 11的速度要慢得多，而不是1.8

Question

将我的程序更新为Java 11之后，使用xsl-fo（AWT渲染器）对XML的转换变得慢得多：Java 11：90秒Java 1.8：5秒

我没有在Java 9或10中尝试过。

在Java 11和1.8的运行之间没有代码，样式表也没有变化。

我正在使用2.3版中的org.apache.xmlgraphics：fop。

不幸的是，还有Saxon-HE 9.9.1-5（代替Xalan），性能也没有改善。

通过性能分析和调试，看起来像类org.apache.fop.layoutmgr.table.TableContentLayoutManager中的代码行284占用时间：

nextRowGroupElems = rowGroupLM.getNextKnuthElements(context, alignment, bodyType);

罪魁祸首是使用AWT的Apache FOP。使用MIME_PDF代替MIME_FOP_AWT_PREVIEW更快：5秒vs 90秒。

分析器（JProfiler）将java.awt.EventDispatchThread显示为Java 11的热点。因此，也许是AWT问题。

要复制的相关代码：

import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;

import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.transform.Result;
import javax.xml.transform.Source;
import javax.xml.transform.Transformer;
import javax.xml.transform.TransformerFactory;
import javax.xml.transform.dom.DOMResult;
import javax.xml.transform.dom.DOMSource;
import javax.xml.transform.sax.SAXResult;

import org.apache.fop.apps.FOUserAgent;
import org.apache.fop.apps.FopConfParser;
import org.apache.fop.apps.FopFactory;
import org.apache.fop.apps.FopFactoryBuilder;
import org.apache.fop.apps.MimeConstants;
import org.springframework.core.io.ClassPathResource;
import org.w3c.dom.Document;
import org.xml.sax.SAXException;

public class MyTransform {

    public static void main(String[] args) throws Exception {
        Document xmlDoc = DocumentBuilderFactory.newInstance().newDocumentBuilder().parse(new FileInputStream("my_xml.xml"));
        Document xslDoc = DocumentBuilderFactory.newInstance().newDocumentBuilder().parse(new File("my_xsl.xsl")); 

        Transformer transformer = TransformerFactory.newInstance().newTransformer(new DOMSource(xslDoc));

        DOMSource xmlDomSource = new DOMSource(xmlDoc);
        DOMResult domResult = new DOMResult();
        transformer.transform(xmlDomSource, domResult);

        Source src = new DOMSource(domResult.getNode());
        Result res = new SAXResult(createFopFactory().newFop(MimeConstants.MIME_FOP_AWT_PREVIEW, getDisplayAgent()).getDefaultHandler());

        TransformerFactory factory = javax.xml.transform.TransformerFactory.newInstance();
        transformer = factory.newTransformer();
        transformer.transform(src, res);

        transformer.transform(src, res); // took with Java 11 90 seconds and with Java 1.8 5 seconds
    }

    private static FopFactory createFopFactory() throws SAXException, IOException {
        ClassPathResource resource = new ClassPathResource("fop_configuration.xml");
        FopConfParser parser = new FopConfParser(resource.getInputStream(), resource.getURI()); //parsing configuration
        FopFactoryBuilder builder = parser.getFopFactoryBuilder(); //building the factory with the user options
        return builder.build();
    }

    private static FOUserAgent getDisplayAgent() throws SAXException, IOException {
        FopFactory fopFactory = createFopFactory();
        FOUserAgent displayAgent = fopFactory.newFOUserAgent();
        MyAWTRendererMaker maker = new MyAWTRendererMaker();
        displayAgent.getRendererFactory().addRendererMaker(maker);
        MyAWTRenderer displayRenderer = new MyAWTRenderer(displayAgent);
        displayAgent.setRendererOverride(displayRenderer);
        return displayAgent;
    }
}

Answer 1

我通过首先生成PDF，然后在ICEpdf对话框而不是Apache FOP中显示它来解决了这个问题。似乎使用输出格式MIME_FOP_AWT_PREVIEW会引起问题，而我现在使用MIME_PDF。