Java实现HTML页面转PDF解决方案
首先，当然是找到能够解析PDF的完美组件，百度和谷歌不约而同的告诉我们。IText是王道。而目前开源的组件中，Itext的确是一个First Choice，如果各位单纯是做把图片转成PDF或者自己写了Velocity或者FreeMarker模板生成了HTML是非常推荐直接用Itext来进行的。而如果，大家像我这样已经有前人写好了HTML页面或者懒得写FreeMarker模板的话。可以直接看下一段。
由于他们已经写好了HTML页面，而且显示已经很完美了。那我要做的就是能完美解析HTML+CSS的PDF生成工具。这时候flying-saucer进入了我的选择范围中。
http://code.google.com/p/flying-saucer/
上面是网址，这个工具托管在GoogleCode上面，作者做他们能够做下面的工作：
Flying Saucer takes XML or XHTML and applies CSS 2.1-compliant stylesheets to it, in order to render to PDF (via iText), images, and on-screen using Swing or SWT。
不难看出工作原理，就是解析XML或者XHTML并且包括css样式表，并且用Swing或者SWT的组件生成PDF的功能。这解决了页面的显示问题。IText自身的一个很严重的问题就是解析CSS有很大的问题。而这个解决了。下面就是用Flying Saucer来实现的代码：
public boolean convertHtmlToPdf(String inputFile, String outputFile)
throws Exception {
OutputStream os = new FileOutputStream(outputFile);
ITextRenderer renderer = new ITextRenderer();
String url = new File(inputFile).toURI().toURL().toString();
renderer.setDocument(url);
// 解决中文支持问题
ITextFontResolver fontResolver = renderer.getFontResolver();
fontResolver.addFont("C:/Windows/Fonts/SIMSUN.TTC", BaseFont.IDENTITY_H, BaseFont.NOT_EMBEDDED);
//解决图片的相对路径问题
renderer.getSharedContext().setBaseURL("file:/D:/");
renderer.layout();
renderer.createPDF(os);
os.flush();
os.close();
return true;
}上面这段代码是这样的，输入一个HTML地址URL = inputFile，输入一个要输出的地址，就可以在输出的PDF地址中生成这个PDF。
注意事项：
1.输入的HTML页面必须是标准的XHTML页面。页面的顶上必须是这样的
TML页面的语法必须是非常严谨的，所有标签都必须闭合等等（由于flying-Saucer做了XML解析的工作，不严谨会报错的。），这是对页面的第一个要求。
2.要用到图片的地方写相对路径的形式，图片位置则必须在Java代码中指定。
renderer.getSharedContext().setBaseURL(“file:/D:/”);
也有另一种方法就是直接在标签中写绝对路径。
3.Flying-Saucer在解析tiff格式的图片的时候会报错。具体原因我还没找到。希望大家能够指点我。
4.如果在页面中有中文字体的话。必须在HTML代码中的样式中写上某种字体的css，并且必须是用英文的，然后在Java代码中写上对应的文件位置。
ITextFontResolver fontResolver = renderer.getFontResolver();
fontResolver.addFont("C:/Windows/Fonts/SIMSUN.TTC", BaseFont.IDENTITY_H, BaseFont.NOT_EMBEDDED);上面的方法是添加了宋体。也可以添加其他字体。
以上就是解决方案。
下面给出这几个包的下载地址。大家可以直接下载。
http://download.csdn.net/detail/jasonchris/4403777
网上遇到一个问题
I am trying to use flyingsaucer to serve pdf generated from xhtml but I am having trouble getting the servlet example to run.
All the other flyingsaucer examples work fine for me but I need this to work as a servlet to incorporate into a webapp.
The full code for the servlet is as follows
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";
}
}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)
...
解决方法
String css = getServletContext().getRealPath("/PDFservlet.css");This is not right. It has to be an URL, not a local disk file system path. IText is attempting to download it by an URL “the usual way”, like as a webbrowser would do.
One of the ways to construct the proper URL would be this:
ringBuffer url = req.getRequestURL();
String base = url.substring(0, url.length() - req.getRequestURI().length() + req.getContextPath().length());
String css = base + "/PDFservlet.css";