利用Applet进行Web打印

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一web打印常见方法：
1，一种简单的方法是在html上调用window.print(),但是这种方法极其“简陋”，除了要弹出一个对话框让我们选择打印机外，还有就是打印的内容不大好控制。
2，利用pdf，先将要打印的内容呈现在pdf上，再点击pdf上的打印按钮，但是一般要执行两步。很多情况下，这是一种不错的选择。
3，利用插件，有ActiveX控件，Applet插件，一下讲解applet打印。
二指定客户端的打印机直接打印
利用java print sevice可以很好地控制打印，此处不直接用Java Print Service，为了更好地控制打印内容的格式，我这里推荐用jasperreport来进行打印。利用applet调用其JRPrintServiceExporter对象来打印。
1，创建一个servlet，负责生产要打印的报表

-----------------------------------------

public class JasperPrintServlet extends HttpServlet
{


/**
*
*/
public void service(
HttpServletRequest request,
HttpServletResponse response
) throws IOException, ServletException
{
ServletContext context = this.getServletConfig().getServletContext();

File reportFile = new File(context.getRealPath("/reports/WebappReport.jasper"));
if (!reportFile.exists())
throw new JRRuntimeException("File WebappReport.jasper not found. The report design must be compiled first.");

Map parameters = new HashMap();
parameters.put("ReportTitle", "Address Report");
parameters.put("BaseDir", reportFile.getParentFile());

JasperPrint jasperPrint = null;

try
{
JasperReport jasperReport = (JasperReport)JRLoader.loadObject(reportFile.getPath());

jasperPrint =
JasperFillManager.fillReport(
jasperReport,
parameters,
new WebappDataSource()
);
}
catch (JRException e)
{
response.setContentType("text/html");
PrintWriter out = response.getWriter();
out.println("");
out.println("");
out.println("");
out.println("");
out.println("");

out.println("");

out.println("JasperReports encountered this error :");
out.println("

"); 

e.printStackTrace(out); 

out.println("

");

out.println("");
out.println("");

return;
}

if (jasperPrint != null)
{
response.setContentType("application/octet-stream");
ServletOutputStream ouputStream = response.getOutputStream();

ObjectOutputStream oos = new ObjectOutputStream(ouputStream);
oos.writeObject(jasperPrint);
oos.flush();
oos.close();

ouputStream.flush();
ouputStream.close();
}
else
{
response.setContentType("text/html");
PrintWriter out = response.getWriter();
out.println("");
out.println("");
out.println("");
out.println("");
out.println("");

out.println("");

out.println("Empty response.");

out.println("");
out.println("");
}
}


}2，创建一个Applet，负责调用servlet，同时执行打印
------------------------------------------------------------------------------
public class HelloSwingApplet extends JApplet
{

private URL url = null;
private JasperPrint jasperPrint = null;

public HelloSwingApplet()
{

}

public void init()
{

String strUrl = getParameter("REPORT_URL");
if (strUrl != null)
{
try
{
url = new URL(getCodeBase(), strUrl);
}
catch (Exception e)
{
StringWriter swriter = new StringWriter();
PrintWriter pwriter = new PrintWriter(swriter);
e.printStackTrace(pwriter);
JOptionPane.showMessageDialog(this, swriter.toString());
}
}
if (url != null)
{
try
{
if (jasperPrint == null)
{
jasperPrint = (JasperPrint)JRLoader.loadObject(url);
}
if (jasperPrint != null)
{
//ViewerFrame viewerFrame = new ViewerFrame(this.getAppletContext(), jasperPrint);
//viewerFrame.show();
}
else
{
JOptionPane.showMessageDialog(this, "Empty report.");
}
}
catch (Exception e)
{
StringWriter swriter = new StringWriter();
PrintWriter pwriter = new PrintWriter(swriter);
e.printStackTrace(pwriter);
JOptionPane.showMessageDialog(this, swriter.toString());
}
}



}
public void printReport() throws Exception{
try {
//JRSaver.saveObject(jasperPrint, "PrintServiceReport.jrprint");
PrintRequestAttributeSet printRequestAttributeSet = new HashPrintRequestAttributeSet();
printRequestAttributeSet.add(MediaSizeName.ISO_A4);

PrintServiceAttributeSet printServiceAttributeSet = new HashPrintServiceAttributeSet();
//指定打印机，不会弹出打印机选择框（PDFill PDF&Image Writer是我的打印机）
printServiceAttributeSet.add(new PrinterName("PDFill PDF&Image Writer", null));

JRPrintServiceExporter exporter = new JRPrintServiceExporter();

exporter.setParameter(JRExporterParameter.JASPER_PRINT, jasperPrint);
exporter.setParameter(JRPrintServiceExporterParameter.PRINT_REQUEST_ATTRIBUTE_SET, printRequestAttributeSet);
exporter.setParameter(JRPrintServiceExporterParameter.PRINT_SERVICE_ATTRIBUTE_SET, printServiceAttributeSet);
exporter.setParameter(JRPrintServiceExporterParameter.DISPLAY_PAGE_DIALOG, Boolean.FALSE);
exporter.setParameter(JRPrintServiceExporterParameter.DISPLAY_PRINT_DIALOG, Boolean.FALSE);

exporter.exportReport();
} catch (JRException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}

3，创建一个html，嵌入applet

1）嵌入代码


2）编写一个js函数
function print(){
  document.applets[0].printReport();
}3）编写一个button测试