使用ApacheXML项目FOP生成PDF文件（下）

使用Apache XML项目FOP生成PDF文件（下）

四、       内容：

2、（2）XMLàXSL-FOàPDF：

有时我们在程序中会遇到要把一个只具有数据，没有格式的XML文件转化成PDF文件，这时我们就需要一个JAXP兼容的XSLT处理器：如Apache的xalan（或者IBM的xerces，Sun的JDOM等），请将它的库文件加入CLASSPATH。通过JAXP的API我们就可以先使用XSLT把XML文件转化为XML-FO文件，再把XML-FO文件转化为PDF。处理流程如下：

XLS-FO

PDF

FOP

XML

XSLT

JAXP

 

 

 

（a）     第一步让我们先看一下如何把XML文件转化为XLS-FO文件，处理流程如下：

XLS-FO

XML

XSLT

JAXP

 

 

 

 

//例二：ExampleXML2FO.java

 

//Java

import java.io.File;

import java.io.IOException;

import java.io.OutputStream;

 

//JAXP

import javax.xml.transform.Transformer;

import javax.xml.transform.TransformerFactory;

import javax.xml.transform.TransformerException;

import javax.xml.transform.Source;

import javax.xml.transform.Result;

import javax.xml.transform.stream.StreamResult;

import javax.xml.transform.stream.StreamSource;

 

//Avalon

import org.apache.avalon.framework.ExceptionUtil;

 

/**

 * This class demonstrates the conversion of an XML file to an XSL-FO file

 * using JAXP (XSLT).

 */

public class ExampleXML2FO {

 

    public void convertXML2FO(File xml, File xslt, File fo)

                throws IOException, TransformerException {

      

        //Setup output

        OutputStream out = new java.io.FileOutputStream(fo);

        try {

            //Setup XSLT

            TransformerFactory factory = TransformerFactory.newInstance();

            Transformer transformer = factory.newTransformer(new StreamSource(xslt));

       

            //Setup input for XSLT transformation

            Source src = new StreamSource(xml);

       

            //Resulting SAX events (the generated FO) must be piped through to FOP

            Result res = new StreamResult(out);

 

            //Start XSLT transformation and FOP processing

            transformer.transform(src, res);

        } finally {

            out.close();

        }

    }

 

 

    public static void main(String[] args) {

        try {

            System.out.println("FOP ExampleXML2FO/n");

            System.out.println("Preparing...");

 

            //Setup directories

            File baseDir = new File(".");

 

 

            //Setup input and output files           

            File xmlfile = new File(baseDir, "projectteam.xml");

            File xsltfile = new File(baseDir, "projectteam2FO.xsl");

            File fofile = new File(baseDir, "ResultXML2FO.fo");

 

            System.out.println("Input: XML (" + xmlfile + ")");

            System.out.println("Stylesheet: " + xsltfile);

            System.out.println("Output: XSL-FO (" + fofile + ")");

            System.out.println();

            System.out.println("Transforming...");

           

            ExampleXML2FO app = new ExampleXML2FO();

            app.convertXML2FO(xmlfile, xsltfile, fofile);

           

            System.out.println("Success!");

        } catch (Exception e) {

            System.err.println(ExceptionUtil.printStackTrace(e));

            System.exit(-1);

        }

    }

}

 

              编译运行上面的程序使用XSLT文件projectteam2FO.xsl把XML文件projectteam.xml转化为XML-FO文件ResultXML2FO.fo。

 

（b）    进一步，我们看一下如何把XML文件转化为PDF文件。

处理流程如下：

XLS-FO

PDF

FOP

XML

XSLT

JAXP

 

 

 

 

//例三：ExampleXML2PDF.java

 

//Java

import java.io.File;

import java.io.IOException;

import java.io.OutputStream;

 

//JAXP

import javax.xml.transform.Transformer;

import javax.xml.transform.TransformerFactory;

import javax.xml.transform.TransformerException;

import javax.xml.transform.Source;

import javax.xml.transform.Result;

import javax.xml.transform.stream.StreamSource;

import javax.xml.transform.sax.SAXResult;

 

//Avalon

import org.apache.avalon.framework.ExceptionUtil;

import org.apache.avalon.framework.logger.ConsoleLogger;

import org.apache.avalon.framework.logger.Logger;

 

//FOP

import org.apache.fop.apps.Driver;

import org.apache.fop.apps.FOPException;

import org.apache.fop.messaging.MessageHandler;

 

/**

 * This class demonstrates the conversion of an XML file to PDF using

 * JAXP (XSLT) and FOP (XSL:FO).

 */

public class ExampleXML2PDF {

 

    public void convertXML2PDF(File xml, File xslt, File pdf)

                throws IOException, FOPException, TransformerException {

        //Construct driver

        Driver driver = new Driver();

       

        //Setup logger

        Logger logger = new ConsoleLogger(ConsoleLogger.LEVEL_INFO);

        driver.setLogger(logger);

        MessageHandler.setScreenLogger(logger);

 

        //Setup Renderer (output format)       

        driver.setRenderer(Driver.RENDER_PDF);

       

        //Setup output

        OutputStream out = new java.io.FileOutputStream(pdf);

        try {

            driver.setOutputStream(out);

 

            //Setup XSLT

            TransformerFactory factory = TransformerFactory.newInstance();

            Transformer transformer = factory.newTransformer(new StreamSource(xslt));

       

            //Setup input for XSLT transformation

            Source src = new StreamSource(xml);

       

            //Resulting SAX events (the generated FO) must be piped through to FOP

            Result res = new SAXResult(driver.getContentHandler());

 

            //Start XSLT transformation and FOP processing

            transformer.transform(src, res);

        } finally {

            out.close();

        }

    }

 

 

    public static void main(String[] args) {

        try {

            System.out.println("FOP ExampleXML2PDF/n");

            System.out.println("Preparing...");

 

            //Setup directories

            File baseDir = new File(".");

 

            //Setup input and output files           

            File xmlfile = new File(baseDir, "projectteam.xml");

            File xsltfile = new File(baseDir, "projectteam2FO.xsl");

            File pdffile = new File(baseDir, "ResultXML2PDF.pdf");

 

            System.out.println("Input: XML (" + xmlfile + ")");

            System.out.println("Stylesheet: " + xsltfile);

            System.out.println("Output: PDF (" + pdffile + ")");

            System.out.println();

            System.out.println("Transforming...");

           

            ExampleXML2PDF app = new ExampleXML2PDF();

            app.convertXML2PDF(xmlfile, xsltfile, pdffile);

           

            System.out.println("Success!");

        } catch (Exception e) {

            System.err.println(ExceptionUtil.printStackTrace(e));

            System.exit(-1);

        }

    }

}

 

 

              编译运行上面的程序使用XSLT文件projectteam2FO.xsl把XML文件projectteam.xml转化为PDF文件ResultXML2PDF.pdf。

 

（3）JAVAàXMLàXSL-FOàPDF：

这种情况有兴趣的读者可以参考http://xml.apache.org/ 关于FOP的介绍。

 

参考资料：http://xml.apache.org/

作者邮箱：jasea@sina.com