Adding Ajax Behavior for Generate PDF in Apache wicket

Step 1: Override the 'AbstractAjaxBehavior' class functionality as below.

public abstract class ClassName extends AbstractAjaxBehavior {

      public void initiate(AjaxRequestTarget target) {

        target.appendJavascript("window.open('" + getCallbackUrl()

            + "', '', 'scrollbars=yes,location=no,menuBar=no,resizable=yes,status=no,toolbar=no')");

    }

    // Called when a request to a behavior is received.

    @Override

    public void onRequest() {

        RequestCycle rc = getComponent().getRequestCycle();

        final WebResponse webResponse = (WebResponse) getComponent().getRequestCycle().getResponse();

        webResponse.setLastModifiedTime(Time.now());

        webResponse.setContentType("application/pdf");

        webResponse.setHeader("Content-Disposition", "inline; filename=\"" + getFileName() + "\"");

        rc.setRequestTarget(new IRequestTarget() {

            public void respond(RequestCycle requestCycle) {

                OutputStreamWriter writer = null;

                try {

                    OutputStream stream = webResponse.getOutputStream();

                    writer = new OutputStreamWriter(stream, "ISO-8859-1");

                    writer.write(getStringToWriteonPDF());

                    writer.flush();

                } catch (IOException ioException) {

                    ioException.printStackTrace();

                } finally {

                    try {

                        writer.close();

                    } catch (IOException ioException) {

                    }

                }

            }

            public void detach(RequestCycle requestCycle) {

            }

        });

    }

    protected abstract String getFileName();

    protected abstract String getStringToWriteonPDF();

}

Step 2: Use the override behavior in Component class

public void onClick(AjaxRequestTarget target) {
  ClassName  behavior =  new ClassName () {
             private static final long serialVersionUID = 1L;
             @Override
             protected String getStringToWriteonPDF() {
                  return "out put of PDF-it may get from Source (Database/webservices)";
             }
             @Override
             protected String getFileName() {
                  return "File Name of PDF";
             }
          };
                  add(behavior);
             behavior.initiate(target);
}