Export Grid or Listbox to PDF or Excel
Export Grid or Listbox to PDF or Excel
Sam Chuang, Engineer, Potix Corporation
November 26, 2012
ZK 6.0 and later
Introduction
Web application developers often require to transform data into different format. For instance, to PDF format that enhance read accessibility and to Excel format that can further analyze data. This smalltalk is going to introduce a easy way that can transform from Grid or Listbox to PDF/Excel.
Demo
Usage
Export Listbox/Grid
As you can see the following sample code, export Listbox/Grid to PDF or Excel is quite straightforward.
@Command
public void exportGrid(@BindingParam("ref") Grid grid) throws Exception {
ByteArrayOutputStream out = new ByteArrayOutputStream();
PdfExporter exporter = new PdfExporter();
exporter.export(grid, out);
AMedia amedia = new AMedia("FirstReport.pdf", "pdf", "application/pdf", out.toByteArray());
Filedownload.save(amedia);
out.close();
}
Excel
@Command
public void exportListboxToExcel(@BindingParam("ref") Listbox listbox) throws Exception {
ByteArrayOutputStream out = new ByteArrayOutputStream();
ExcelExporter exporter = new ExcelExporter();
exporter.export(listbox, out);
AMedia amedia = new AMedia("FirstReport.xlsx", "xls", "application/file", out.toByteArray());
Filedownload.save(amedia);
out.close();
}
Export data by Renderer
Although export Listbox/Grid to PDF or Excel is quite straightforward. However, it does have some limitation. For instance, it cannot export full contents with Grid/Listbox with ROD enabled. In such use case, you can use renderer to render raw data to PDF/Excel directly. Another advantage of renderer is that you can highly customize the rendering result.
The PdfExporter leverage the famous iText library to create PDF documents. Renderer will use iText API directly.
The PdfExporter contains Factories that help create necessary instances that iText needed.
1. DocumentFactory to create Document
2. PdfWriterFactory to get PdfWriter instance
3. PdfPTableFactory to get PdfPTable instance
4. FontFactory to get Font
5. PdfPCellFactory to create PdfPCell
The following sample code will demonstrate the usage of FontFactory and PdfPCellFactory
- Render header using Interceptor.beforeRendering API
final PdfExporter exporter = new PdfExporter();
final PdfPCellFactory cellFactory = exporter.getPdfPCellFactory();
final FontFactory fontFactory = exporter.getFontFactory();
final String[] headers = new String[]{"Name", "Top Nutrients", "% of Daily", "Calories", "Quantity"};
exporter.setInterceptor(new Interceptor <PdfPTable> () {
@Override
public void beforeRendering(PdfPTable table) {
for (int i = 0; i < headers.length; i++) {
String header = headers[i];
Font font = fontFactory.getFont(FontFactory.FONT_TYPE_HEADER);
PdfPCell cell = cellFactory.getHeaderCell();
cell.setPhrase(new Phrase(header, font));
if ("% of Daily".equals(header) || "Calories".equals(header)) {
cell.setHorizontalAlignment(Element.ALIGN_CENTER);
}
table.addCell(cell);
}
table.completeRow();
}
@Override
public void afterRendering(PdfPTable table) {
}
});
- Render contents using RowRenderer or GroupRenderer
exporter.export(headers.length, _model.getData(), new GroupRenderer<PdfPTable, Food>() {
@Override
public void render(PdfPTable table, Food food, boolean isOddRow) {
Font font = fontFactory.getFont(FontFactory.FONT_TYPE_CELL);
PdfPCell cell = cellFactory.getCell(isOddRow);
cell.setPhrase(new Phrase(food.getName(), font));
table.addCell(cell);
cell = cellFactory.getCell(isOddRow);
cell.setPhrase(new Phrase(food.getTopNutrients(), font));
table.addCell(cell);
cell = cellFactory.getCell(isOddRow);
cell.setPhrase(new Phrase("" + food.getDailyPercent(), font));
cell.setHorizontalAlignment(Element.ALIGN_CENTER);
table.addCell(cell);
cell = cellFactory.getCell(isOddRow);
cell.setPhrase(new Phrase("" + food.getCalories(), font));
cell.setHorizontalAlignment(Element.ALIGN_CENTER);
table.addCell(cell);
cell = cellFactory.getCell(isOddRow);
cell.setPhrase(new Phrase(food.getQuantity(), font));
table.addCell(cell);
table.completeRow();
}
@Override
public void renderGroup(PdfPTable table, Collection<Food> foods) {
Iterator<Food> iterator = foods.iterator();
if (iterator.hasNext()) {
Food food = iterator.next();
Font font = fontFactory.getFont(FontFactory.FONT_TYPE_GROUP);
PdfPCell cell = cellFactory.getGroupCell();
cell.setPhrase(new Phrase(food.getCategory(), font));
cell.setColspan(headers.length);
table.addCell(cell);
table.completeRow();
}
}
@Override
public void renderGroupfoot(PdfPTable table, Collection<Food> foods) {
Font font = fontFactory.getFont(FontFactory.FONT_TYPE_GROUPFOOT);
PdfPCell cell = cellFactory.getGroupCell();
cell.setPhrase(new Phrase("Total size: " + (foods != null ? foods.size() : 0), font));
table.addCell(cell);
cell = cellFactory.getCell(false);
cell.setColspan(headers.length - 1);
table.addCell(cell);
table.completeRow();
}
}, out);
Excel
Summary
Download
- The demo web application can be downloaded here - Github
- The export.jar can be downloaded here- Github
Comments
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