在浏览器生成PDF文件，主要用了JasperRunManager对象面的runReportToPdfStream方法，在WEB里一般都先用iReport生成jasper文件，这样就去解析JRXML文件了 

例子如下 

 import java.io.IOException;
 import java.io.InputStream;
 import java.io.PrintWriter;
 import java.io.StringWriter;
 import java.util.HashMap;

 import javax.servlet.ServletException;
 import javax.servlet.ServletOutputStream;
 import javax.servlet.http.HttpServlet;
 import javax.servlet.http.HttpServletRequest;
 import javax.servlet.http.HttpServletResponse;

 import net.sf.jasperreports.engine.JREmptyDataSource;
 import net.sf.jasperreports.engine.JRException;
 import net.sf.jasperreports.engine.JasperRunManager;

 public class JasperReportServlet extends HttpServlet {

     private static final long serialVersionUID = 1L;

     public void doGet(HttpServletRequest request, HttpServletResponse response)
             throws ServletException, IOException {
         //获得输出流
         ServletOutputStream outputStream = response.getOutputStream();
         //获得输入流
         InputStream inputStream = getServletConfig().getServletContext().getResourceAsStream("JasperFile//JasperReportFile.jasper");
         try {

             //生成网页的PDF文件
             JasperRunManager.runReportToPdfStream(inputStream, outputStream, new HashMap(), new JREmptyDataSource());
             //设置PDF格式
             response.setContentType("application/pdf");
             outputStream.flush();
             outputStream.close();
         } catch (JRException e) {
             StringWriter stringWriter = new StringWriter();
             PrintWriter printWriter = new PrintWriter(stringWriter);
             e.printStackTrace(printWriter);
             response.setContentType("text/plain");
             response.getOutputStream().print(stringWriter.toString());
         }
     }


     public void doPost(HttpServletRequest request, HttpServletResponse response)
             throws ServletException, IOException {
         this.doPost(request, response);
     }
 }