将 PageSize 更改为更大的值应该可以解决这一特定问题。
之后您可以缩小页面以获得 A4 页面的 PDF。
请查看下面的代码示例,了解如何执行此操作。
public static void main(String[] args) throws IOException {
ByteArrayOutputStream pdf = createPdf("src/main/resources/SO47869248/html.html");
// To get from A3 to A4 the size has to shrink 71%
new SO47869248().scalePdf(DEST, new ByteArrayInputStream(pdf.toByteArray()), 0.7071f);
}
public static ByteArrayOutputStream createPdf(String htmlSrc) throws IOException {
ByteArrayOutputStream output = new ByteArrayOutputStream();
ConverterProperties converterProperties = new ConverterProperties();
converterProperties.setBaseUri(new File(htmlSrc).getParent());
PdfWriter writer = new PdfWriter(output);
PdfDocument pdfDocument = new PdfDocument(writer);
PdfMerger merger = new PdfMerger(pdfDocument);
for(int x=0; x < 3; x++){
ByteArrayOutputStream baos = new ByteArrayOutputStream();
PdfDocument temp = new PdfDocument(new PdfWriter(baos));
temp.setDefaultPageSize(PageSize.A3);
HtmlConverter.convertToPdf(new FileInputStream(htmlSrc), temp, converterProperties);
temp = new PdfDocument(new PdfReader(new ByteArrayInputStream(baos.toByteArray())));
merger.merge(temp, 1, temp.getNumberOfPages());
temp.close();
}
pdfDocument.close();
return output;
}
public void scalePdf(String dest, ByteArrayInputStream input, float scale) throws IOException {
// Create the source document
PdfDocument srcDoc = new PdfDocument(new PdfReader(input));
PdfDocument pdfDoc = new PdfDocument(new PdfWriter(dest));
ScaleDownEventHandler eventHandler = new ScaleDownEventHandler(scale);
int n = srcDoc.getNumberOfPages();
pdfDoc.addEventHandler(PdfDocumentEvent.START_PAGE, eventHandler);
PdfCanvas canvas;
PdfFormXObject page;
for (int p = 1; p <= n; p++) {
eventHandler.setPageDict(srcDoc.getPage(p).getPdfObject());
canvas = new PdfCanvas(pdfDoc.addNewPage());
page = srcDoc.getPage(p).copyAsFormXObject(pdfDoc);
canvas.addXObject(page, scale, 0f, 0f, scale, 0f, 0f);
}
pdfDoc.close();
srcDoc.close();
}
protected class ScaleDownEventHandler implements IEventHandler {
protected float scale = 1;
protected PdfDictionary pageDict;
public ScaleDownEventHandler(float scale) {
this.scale = scale;
}
public void setPageDict(PdfDictionary pageDict) {
this.pageDict = pageDict;
}
@Override
public void handleEvent(Event event) {
PdfDocumentEvent docEvent = (PdfDocumentEvent) event;
PdfPage page = docEvent.getPage();
page.put(PdfName.Rotate, pageDict.getAsNumber(PdfName.Rotate));
scaleDown(page, pageDict, PdfName.MediaBox, scale);
scaleDown(page, pageDict, PdfName.CropBox, scale);
}
protected void scaleDown(PdfPage destPage, PdfDictionary pageDictSrc, PdfName box, float scale) {
PdfArray original = pageDictSrc.getAsArray(box);
if (original != null) {
float width = original.getAsNumber(2).floatValue() - original.getAsNumber(0).floatValue();
float height = original.getAsNumber(3).floatValue() - original.getAsNumber(1).floatValue();
PdfArray result = new PdfArray();
result.add(new PdfNumber(0));
result.add(new PdfNumber(0));
result.add(new PdfNumber(width * scale));
result.add(new PdfNumber(height * scale));
destPage.put(box, result);
}
}
}
在本例中,我选择了 A3 页面大小常量。您还可以使用特定测量值创建 PageSize 对象。如下所示:
构造函数:
public PageSize(float width, float height)
Example:
PageSize pageSize = new PageSize(750, 1000);
PdfDocument temp = new PdfDocument(pageSize);