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java-xhtml到带有flyingsaucer的pdf servlet

2019-10-31 11:03:37 作者：互联网

我正在尝试使用flyingsaucer服务从xhtml生成的pdf,但是我无法让servlet示例运行.

所有其他flyingsaucer示例对我来说都可以正常工作,但是我需要将它用作一个servlet并集成到webapp中.

servlet的完整代码如下：

import java.io.*;
import java.net.*;

import javax.servlet.*;
import javax.servlet.http.*;
import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import org.w3c.dom.Document;
import org.xhtmlrenderer.pdf.ITextRenderer;

public class PDFServlet extends HttpServlet {

    protected void processRequest(HttpServletRequest request, 
        HttpServletResponse response) throws ServletException, IOException {
        response.setContentType("application/pdf");

        StringBuffer buf = new StringBuffer();
        buf.append("<html>");

        String css = getServletContext().getRealPath("/PDFservlet.css");
        System.out.println("css url 2= " + css);
        // put in some style
        buf.append("<head><link rel='stylesheet' type='text/css' "+
                "href='"+css+"' media='print'/></head>");

        buf.append("<body>");
        buf.append("<h1>Quarterly Reports for " +
            request.getParameter("username")+"</h1>");

        buf.append("<table cellspacing='0'>");
        buf.append("<tr><th>Sales</th><th>Profit</th><th>Bonus</th></tr>");

        // generate sales data
        int totalSales = 0;
        int totalProfit = 0;
        int totalBonus = 0;
        for(int i=0; i<10; i++) {
            int currentSales = (int)(Math.random()*10000);
            int currentProfit = (int)(currentSales*0.2);
            int currentBonus = (int)(currentProfit*0.33);
            buf.append("<tr><td>"+currentSales+"$</td><td>"+
                currentProfit+"$</td><td>"+currentBonus+"$</td></tr>");
            totalSales  += currentSales;
            totalProfit += currentProfit;
            totalBonus  += currentBonus;
        }

        buf.append("<tr class='total-header'><td colspan='3'>totals</td></tr>");
        buf.append("<tr class='total'><td>"+totalSales+"$</td><td>"+
            totalProfit+"$</td><td>"+totalBonus+"$</td></tr>");
        buf.append("</table>");

        buf.append("</body>");
        buf.append("</html>");

        byte[] byteArray = buf.toString().getBytes("ISO-8859-1"); 

        // parse our markup into an xml Document
        DocumentBuilder builder;
        try {
            builder = DocumentBuilderFactory.newInstance().newDocumentBuilder();
            ByteArrayInputStream baos = new ByteArrayInputStream(byteArray); 
            Document doc = builder.parse(baos);

            ITextRenderer renderer = new ITextRenderer();
            renderer.setDocument(doc, null);

            OutputStream os = response.getOutputStream();
            renderer.layout();
            renderer.createPDF(os);
            os.flush();
            os.close();
        } catch (Exception ex) {
            ex.printStackTrace();
        }
    }

    protected void doGet(HttpServletRequest request, 
        HttpServletResponse response) throws ServletException, IOException {
        processRequest(request, response);
    }

    protected void doPost(HttpServletRequest request, 
        HttpServletResponse response) throws ServletException, IOException {
        processRequest(request, response);
    }

    public String getServletInfo() {
        return "Short description";
    }
}

我得到这个例外：

Jan 17, 2013 7:55:23 PM org.xhtmlrenderer.util.XRLog log
WARNING: Unhandled exception. IOException on parsing style seet from a Reader; don't know the URI.
java.io.IOException: Stream closed
    at java.io.BufferedInputStream.getInIfOpen(Unknown Source)
    at java.io.BufferedInputStream.read1(Unknown Source)
    at java.io.BufferedInputStream.read(Unknown Source)
    at sun.nio.cs.StreamDecoder.readBytes(Unknown Source)
    at sun.nio.cs.StreamDecoder.implRead(Unknown Source)
    at sun.nio.cs.StreamDecoder.read(Unknown Source)
    at java.io.InputStreamReader.read(Unknown Source)
    at org.xhtmlrenderer.css.parser.Lexer.zzRefill(Lexer.java:1527)
    ...
    at org.xhtmlrenderer.context.StyleReference.readAndParseAll(StyleReference.java:122)
    at org.xhtmlrenderer.context.StyleReference.setDocumentContext(StyleReference.java:106)
    at org.xhtmlrenderer.pdf.ITextRenderer.setDocument(ITextRenderer.java:130)
    at org.xhtmlrenderer.pdf.ITextRenderer.setDocument(ITextRenderer.java:106)
    at PDFServlet.processRequest(PDFServlet.java:73)
    at PDFServlet.doGet(PDFServlet.java:75)
    ...

它不会超出此行(在try-catch块中)：

renderer.setDocument(doc, null);

我尝试了一些操作,例如更改输入流类型并验证xhtml是否运行正常,但这并不能解决任何问题.

我对Java servlet并不十分熟悉,所以我不确定是否要解决正确的问题,看来我需要找到某种方法来防止输入流在运行前被关闭：

renderer.setDocument(doc, null);

这是可能的还是我应该解决其他问题？

我使用的是Tomcat 7和Java6.我注意到其他人使用的是similar problem,但是我只有在运行servlet示例时才知道它-其他所有示例都运行良好.

解决方法:

String css = getServletContext().getRealPath("/PDFservlet.css");

这是不对的.它必须是URL,而不是本地磁盘文件系统路径. IText尝试通过URL“通常的方式”下载它,就像Web浏览器一样.

构造适当的URL的方法之一是：

StringBuffer url = req.getRequestURL();
String base = url.substring(0, url.length() - req.getRequestURI().length() + req.getContextPath().length());
String css = base + "/PDFservlet.css";

标签：servlets,pdf-generation,flying-saucer,java
来源： https://codeday.me/bug/20191031/1975290.html