如何在 Spring MVC Web 应用程序中将 Apache FOP 与 Velocity 结合使用？

发布于 2024-12-04 08:57:08 字数 1643 浏览 2 评论 0原文

我在 Spring 上下文中对 Velocity 进行了简单的配置（根据官方 Spring 文档）并且工作正常。如何配置/将其与 Apache FOP 集成并生成 pdf 文档？如果有一些例子，我将不胜感激。

<!-- velocity -->
<bean id="velocityConfig" class="org.springframework.web.servlet.view.velocity.VelocityConfigurer">
    <property name="resourceLoaderPath" value="/WEB-INF/velocity/"/>
</bean>
<bean id="velocityViewResolver" class="org.springframework.web.servlet.view.velocity.VelocityViewResolver">
    <property name="cache" value="true"/>
    <property name="prefix" value=""/>
    <property name="suffix" value=".vm"/>
</bean>

测试控制器：

@Controller
@RequestMapping("/doc")
public class DocumentController {

    @RequestMapping("/test")
    public ModelAndView velocityTest() {
        List<String> xmens = new ArrayList<String>();
        xmens.add("Professor X");
        xmens.add("Cyclops");
        xmens.add("Iceman");
        xmens.add("Archangel");
        xmens.add("Beast");
        xmens.add("Phoenix");
        Map<String, List<String>> model = new HashMap<String, List<String>>();
        model.put("xmens", xmens);
        return new ModelAndView("testdoc", model);      
    }
}

/WEB-INF/velocity/test.vm

<html>
    <body>
        <ul>
        #foreach ($xmen in $xmens)
            <li>$xmen</li>
        #end
        </ul>
    </body>
</html>

原文

I have simple configuration of Velocity in Spring context (according to an official Spring documentation) and works ok. How to configure/integrate this with Apache FOP and generate pdf documents ? I would be grateful for some examples.

<!-- velocity -->
<bean id="velocityConfig" class="org.springframework.web.servlet.view.velocity.VelocityConfigurer">
    <property name="resourceLoaderPath" value="/WEB-INF/velocity/"/>
</bean>
<bean id="velocityViewResolver" class="org.springframework.web.servlet.view.velocity.VelocityViewResolver">
    <property name="cache" value="true"/>
    <property name="prefix" value=""/>
    <property name="suffix" value=".vm"/>
</bean>

Test controller:

@Controller
@RequestMapping("/doc")
public class DocumentController {

    @RequestMapping("/test")
    public ModelAndView velocityTest() {
        List<String> xmens = new ArrayList<String>();
        xmens.add("Professor X");
        xmens.add("Cyclops");
        xmens.add("Iceman");
        xmens.add("Archangel");
        xmens.add("Beast");
        xmens.add("Phoenix");
        Map<String, List<String>> model = new HashMap<String, List<String>>();
        model.put("xmens", xmens);
        return new ModelAndView("testdoc", model);      
    }
}

/WEB-INF/velocity/test.vm

<html>
    <body>
        <ul>
        #foreach ($xmen in $xmens)
            <li>$xmen</li>
        #end
        </ul>
    </body>
</html>

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忱杏 2024-12-11 08:57:08

我这样做了，但我认为这肯定是一个更优雅的解决方案（testpdf.vm和testpdf.xsl位于/WEB-INF/velocity< /代码>）。

@Controller
@RequestMapping("/doc")
public class DocumentController {

    @Autowired
    private PdfReportService pdfReportService;

    @RequestMapping("/pdf")
    public void testPdf(HttpServletResponse response) throws IOException {
        Map<String, Object> model = new HashMap<String,Object>(); 
        model.put("message", "Hello World!");
        pdfReportService.generatePdf("testpdf", model, response.getOutputStream());
    }

}

pdf报告服务：

import java.io.ByteArrayInputStream;
import java.io.InputStream;
import java.io.OutputStream;
import java.io.StringWriter;
import java.util.Map;

import javax.servlet.ServletContext;
import javax.xml.transform.Result;
import javax.xml.transform.Source;
import javax.xml.transform.Transformer;
import javax.xml.transform.TransformerFactory;
import javax.xml.transform.sax.SAXResult;
import javax.xml.transform.stream.StreamSource;

import org.apache.fop.apps.Fop;
import org.apache.fop.apps.FopFactory;
import org.apache.fop.apps.MimeConstants;
import org.apache.log4j.Logger;
import org.apache.velocity.Template;
import org.apache.velocity.VelocityContext;
import org.apache.velocity.app.VelocityEngine;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
import org.springframework.web.servlet.view.velocity.VelocityConfigurer;

@Service("pdfReportService")
public class PdfReportService {

    private final Logger log = Logger.getLogger(getClass());

    @Autowired
    private VelocityConfigurer velocityConfig;

    @Autowired
    private ServletContext servletContext; 

    public void generatePdf(String templateName, Map<String,Object>model, OutputStream out) {

        // get an engine
        final VelocityEngine engine = velocityConfig.getVelocityEngine();

        // get the Template
        Template template = engine.getTemplate(templateName+".vm");

        // create a context and add data
        VelocityContext context = new VelocityContext();
        context.put("model", model);

        // render the template into a StringWriter
        StringWriter writer = new StringWriter();
        template.merge(context, writer);

        FopFactory fopFactory = FopFactory.newInstance();

        try {
            //Setup FOP
            Fop fop = fopFactory.newFop(MimeConstants.MIME_PDF, out);

            //Setup Transformer
            InputStream xstlIn = servletContext.getResourceAsStream("/WEB-INF/velocity/"+templateName+".xsl");
            TransformerFactory tFactory = TransformerFactory.newInstance();
            Transformer transformer = tFactory.newTransformer(new StreamSource(xstlIn));

            //Make sure the XSL transformation's result is piped through to FOP
            Result res = new SAXResult(fop.getDefaultHandler());

            //Setup input
            byte[] bytes = writer.toString().getBytes("UTF-8");
            Source src = new StreamSource(new ByteArrayInputStream(bytes));

            //Start XSLT transformation and FOP processing
            transformer.transform(src, res);

        } catch (Exception e) {
            log.error(e.getMessage(), e);
        }
    }

}

I did it this way, but I think it is certainly a more elegant solution (testpdf.vm and testpdf.xsl are in /WEB-INF/velocity).

@Controller
@RequestMapping("/doc")
public class DocumentController {

    @Autowired
    private PdfReportService pdfReportService;

    @RequestMapping("/pdf")
    public void testPdf(HttpServletResponse response) throws IOException {
        Map<String, Object> model = new HashMap<String,Object>(); 
        model.put("message", "Hello World!");
        pdfReportService.generatePdf("testpdf", model, response.getOutputStream());
    }

}

PdfReportService:

import java.io.ByteArrayInputStream;
import java.io.InputStream;
import java.io.OutputStream;
import java.io.StringWriter;
import java.util.Map;

import javax.servlet.ServletContext;
import javax.xml.transform.Result;
import javax.xml.transform.Source;
import javax.xml.transform.Transformer;
import javax.xml.transform.TransformerFactory;
import javax.xml.transform.sax.SAXResult;
import javax.xml.transform.stream.StreamSource;

import org.apache.fop.apps.Fop;
import org.apache.fop.apps.FopFactory;
import org.apache.fop.apps.MimeConstants;
import org.apache.log4j.Logger;
import org.apache.velocity.Template;
import org.apache.velocity.VelocityContext;
import org.apache.velocity.app.VelocityEngine;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
import org.springframework.web.servlet.view.velocity.VelocityConfigurer;

@Service("pdfReportService")
public class PdfReportService {

    private final Logger log = Logger.getLogger(getClass());

    @Autowired
    private VelocityConfigurer velocityConfig;

    @Autowired
    private ServletContext servletContext; 

    public void generatePdf(String templateName, Map<String,Object>model, OutputStream out) {

        // get an engine
        final VelocityEngine engine = velocityConfig.getVelocityEngine();

        // get the Template
        Template template = engine.getTemplate(templateName+".vm");

        // create a context and add data
        VelocityContext context = new VelocityContext();
        context.put("model", model);

        // render the template into a StringWriter
        StringWriter writer = new StringWriter();
        template.merge(context, writer);

        FopFactory fopFactory = FopFactory.newInstance();

        try {
            //Setup FOP
            Fop fop = fopFactory.newFop(MimeConstants.MIME_PDF, out);

            //Setup Transformer
            InputStream xstlIn = servletContext.getResourceAsStream("/WEB-INF/velocity/"+templateName+".xsl");
            TransformerFactory tFactory = TransformerFactory.newInstance();
            Transformer transformer = tFactory.newTransformer(new StreamSource(xstlIn));

            //Make sure the XSL transformation's result is piped through to FOP
            Result res = new SAXResult(fop.getDefaultHandler());

            //Setup input
            byte[] bytes = writer.toString().getBytes("UTF-8");
            Source src = new StreamSource(new ByteArrayInputStream(bytes));

            //Start XSLT transformation and FOP processing
            transformer.transform(src, res);

        } catch (Exception e) {
            log.error(e.getMessage(), e);
        }
    }

}

回复收藏 0 原文

云裳 2024-12-11 08:57:08

我完全按照 marioosh 的方式做的。后来，当我们有很多用户同时进行 PDF 对话时，我们在大型 Web 应用程序中遇到了问题（内存不足），因为 VelocityEngine 和 Apache FOP 都需要一些（大量）内存，并且当您有许多并发用户时，这总结起来。

我们改变了流媒体的方式。 Velocity 现在将 XSL-FO 流式传输到 Apache FOP。 FOP 将结果流式传输到客户端。我们使用 PipedReader / PipedWriter。请注意，此解决方案需要额外的线程。我无法分享此代码，因为我们为我们的客户这样做了。

同时，我找到了一个用于在网络上进行流传输的现有解决方案，请参阅存档。但请注意，此解决方案通过 new Thread(worker).start(); 创建一个额外的线程
在应用程序服务器中，您应该使用改为 WorkManager。另请参阅 http://www.devx.com/java/Article/28815/1954< /a>