java 二维码

要将页面报表导出到pdf中，但是报表中有checkbox复选框，需要要后台利用itext生成，生成复选框的方法如下： 
PdfContentByte cb = writer.getDirectContent();
cb.moveTo(0, 0);
PdfFormField field = PdfFormField.createCheckBox(writer);
PdfAppearance tpOff = cb.createAppearance(20, 20);
PdfAppearance tpOn = cb.createAppearance(20, 20);
tpOff.rectangle(1, 1, 18, 18);
tpOff.stroke(); 
//
tpOn.setRGBColorFill(255, 128, 128);
tpOn.rectangle(1, 1, 18, 18);
tpOn.fillStroke();
tpOn.moveTo(1, 1);
tpOn.lineTo(19, 19);
tpOn.moveTo(1, 19);
tpOn.lineTo(19, 1);
tpOn.stroke();

field.setWidget(new Rectangle(100, 700, 120, 720), PdfAnnotation.HIGHLIGHT_INVERT);
field.setFieldName("Urgent");
field.setValueAsName("On");
field.setAppearanceState("Off"); 
//            field.setAppearance(PdfAnnotation.APPEARANCE_NORMAL, "Off", tpOff); 
//            field.setAppearance(PdfAnnotation.APPEARANCE_NORMAL, "On", tpOn);
writer.addAnnotation(field);