As a beginner in android, I was having a hard time converting html to pdf, every time I convert the html to pdf the result image inside the pdf file is small. How can I solve this problem? This code I am using to convert the html:
PdfWriter writer = PdfWriter.getInstance(document, new FileOutputStream(file));
document.open();
InputStream htmlPath = getAssets().open(filename + ".html");
XMLWorkerHelper helper = XMLWorkerHelper.getInstance();
helper.parseXHtml(writer, document, htmlPath);
document.close();
writer.close();
this is the result:
Related
I am using itextpdf html2pdf tool to implement freemarker template to generate pdf
Refer to the official documentation link：
https://kb.itextpdf.com/home/it7kb/ebooks/itext-7-converting-html-to-pdf-with-pdfhtml/chapter-7-frequently-asked-questions-about-pdfhtml/can-pdfhtml-render-base64-images-to-pdf
The front end uses echarts to convert the image to base64.
The picture can be displayed clearly on the browser, but after the pdf is generated, the picture becomes blurry.
Refer to html and pdf image comparison：
html pdf
public static void main(String[] args) throws Exception{
File file = FileUtil.newFile("D:/test.html");
BufferedOutputStream outputStream = FileUtil.getOutputStream("D:/test.pdf");
BufferedInputStream inputStream = FileUtil.getInputStream(file);
ConverterProperties converterProperties=new ConverterProperties();
FontProvider fontProvider=new DefaultFontProvider();
FontProgram fontProgram = FontProgramFactory.createFont(Constant.CONFIG_PATH+File.separator+"simsun.ttc,1");
fontProvider.addFont(fontProgram);
MediaDeviceDescription mediaDeviceDescription = new MediaDeviceDescription(MediaType.SCREEN);
mediaDeviceDescription.setResolution(2000f);
converterProperties.setFontProvider(fontProvider);
converterProperties.setMediaDeviceDescription(mediaDeviceDescription);
PdfDocument pdfDoc = new PdfDocument(new PdfWriter(outputStream));
pdfDoc.setDefaultPageSize(new PageSize(1000,1700));
HtmlConverter.convertToPdf(inputStream,pdfDoc,converterProperties);
}
I am trying to convert html to pdf with iText API(itextpdf.5.5.7.jar, xmlworker 5.5.7.jar), everything is good except the text inside the pre tag.
In html the text inside the pre is good but in PDF the formatting is totally gone and simply coming in normal lines without formatting. I checked the blogs but I did not find correct answer.
Please find the screen shots for HTML and PDF.
HTML screen:
PDF screen:
this is my code
String pdfFileName="C:\test.pdf";
com.itextpdf.text.Document document = new com.itextpdf.text.Document();
PdfWriter writer = PdfWriter.getInstance(document,
new FileOutputStream(pdfFileName));
writer.setInitialLeading(12.5f);
document.open();
HtmlPipelineContext htmlContext = new HtmlPipelineContext(null);
htmlContext.setTagFactory(Tags.getHtmlTagProcessorFactory());
CSSResolver cssResolver = XMLWorkerHelper.getInstance()
.getDefaultCssResolver(true);
Pipeline<?> pipeline = new CssResolverPipeline(cssResolver,
new HtmlPipeline(htmlContext, new PdfWriterPipeline(document,
writer)));
XMLWorker worker = new XMLWorker(pipeline, true);
XMLParser p = new XMLParser(worker);
File input = new File(completeHtmlFilePath);
p.parse(new InputStreamReader(new FileInputStream(input), "UTF-8"));
document.close();
return pdfFileNameWithPath;
I would like to open an existing pdf, add some text and then output as content disposition using itext sharp. I have the following code. Where it falls down it is that i want to output as memory stream but need to filestream to open the original file.
Here's what i have. Obviously defining PdfWriter twice won't work.
public static void Create(string path)
{
var Response = HttpContext.Current.Response;
Response.Clear();
Response.ContentType = "application/pdf";
System.IO.MemoryStream m = new System.IO.MemoryStream();
Document document = new Document();
PdfWriter wri = PdfWriter.GetInstance(document, new FileStream(path, FileMode.Create));
PdfWriter.GetInstance(document, m);
document.Open();
document.Add(new Paragraph(DateTime.Now.ToString()));
document.NewPage();
document.Add(new Paragraph("Hello World"));
document.Close();
Response.OutputStream.Write(m.GetBuffer(), 0, m.GetBuffer().Length);
Response.OutputStream.Flush();
Response.OutputStream.Close();
Response.End();
}
You've got a couple of problems that I'll try to walk you through.
First, the Document object is only for working with new PDFs, not modifying existing ones. Basically the Document object is a bunch of wrapper classes that abstract away the underlying parts of the PDF spec and allow you to work with higher level things like paragraphs and reflowable content. These abstractions turn what you think of "paragraphs" into raw commands that write the paragraph one line at a time with no relationship between lines. When working with an existing document there's no safe way to say how to reflow text so these abstractions aren't used.
Instead you want to use the PdfStamper object. When working with this object you have two choices for how to work with potentially overlapping content, either your new text gets written on top of existing content or your text gets written below it. The two methods GetOverContent() or GetUnderContent() of an instantiated PdfStamper object will return a PdfContentByte object that you can then write text with.
There's two main ways to write text, either manually or through a ColumnText object. If you've done HTML you can think of the ColumnText object as using a big fixed-position single row, single column <TABLE>. The advantage of the ColumnText is that you can use the higher level abstractions such as Paragraph.
Below is a full working C# 2010 WinForms app targeting iTextSharp 5.1.2.0 that show off the above. See the code comments for any questions. It should be pretty easy to convert this to ASP.Net.
using System;
using System.IO;
using System.Windows.Forms;
using iTextSharp.text;
using iTextSharp.text.pdf;
namespace WindowsFormsApplication1 {
public partial class Form1 : Form {
public Form1() {
InitializeComponent();
}
private void Form1_Load(object sender, EventArgs e) {
string existingFile = Path.Combine(Environment.GetFolderPath(Environment.SpecialFolder.Desktop), "file1.pdf");
string newFile = Path.Combine(Environment.GetFolderPath(Environment.SpecialFolder.Desktop), "file2.pdf");
using (FileStream fs = new FileStream(existingFile, FileMode.Create, FileAccess.Write, FileShare.None)) {
using (Document doc = new Document(PageSize.LETTER)) {
using (PdfWriter writer = PdfWriter.GetInstance(doc, fs)) {
doc.Open();
doc.Add(new Paragraph("This is a test"));
doc.Close();
}
}
}
//Bind a PdfReader to our first document
PdfReader reader = new PdfReader(existingFile);
//Create a new stream for our output file (this could be a MemoryStream, too)
using (FileStream fs = new FileStream(newFile, FileMode.Create, FileAccess.Write, FileShare.None)) {
//Use a PdfStamper to bind our source file with our output file
using (PdfStamper stamper = new PdfStamper(reader, fs)) {
//In case of conflict we want our new text to be written "on top" of any existing content
//Get the "Over" state for page 1
PdfContentByte cb = stamper.GetOverContent(1);
//Begin text command
cb.BeginText();
//Set the font information
cb.SetFontAndSize(BaseFont.CreateFont(BaseFont.HELVETICA, BaseFont.CP1250, false), 16f);
//Position the cursor for drawing
cb.MoveText(50, 50);
//Write some text
cb.ShowText("This was added manually");
//End text command
cb.EndText();
//Create a new ColumnText object to write to
ColumnText ct = new ColumnText(cb);
//Create a single column who's lower left corner is at 100x100 and upper right is at 500x200
ct.SetSimpleColumn(100,100,500,200);
//Add a higher level object
ct.AddElement(new Paragraph("This was added using ColumnText"));
//Flush the text buffer
ct.Go();
}
}
this.Close();
}
}
}
As to your second problem about the FileStream vs MemoryStream, if you look at the method signature for almost every (actually all as far as I know) method within iTextSharp you'll see that they all take a Stream object and not just a FileStream object. Any time you see this, even outside of iTextSharp, this means that you can pass in any subclass of Stream which includes the MemoryStream object, everything else stays the same.
The code below is a slightly modified version of the one above. I've removed most of the comments to make it shorter. The main change is that we're using a MemoryStream instead of a FileStream. Also, when we're done with the PDF when need to close the PdfStamper object before accessing the raw binary data. (The using statment will do this for us automatically later but it also closes the stream so we need to manually do it here.)
One other thing, never, ever use the GetBuffer() method of the MemoryStream. It sounds like what you want (and I have mistakenly used it, too) but instead you want to use ToArray(). GetBuffer() includes uninitialized bytes which usually produces corrupt PDFs. Also, instead of writing to the HTTP Response stream I'm saving the bytes to array first. From a debugging perspective this allows me to finish all of my iTextSharp and System.IO code and make sure that it is correct, then do whatever I want with the raw byte array. In my case I don't have a web server handy so I'm writing them to disk but you could just as easily call Response.BinaryWrite(bytes)
string existingFile = Path.Combine(Environment.GetFolderPath(Environment.SpecialFolder.Desktop), "file1.pdf");
string newFile = Path.Combine(Environment.GetFolderPath(Environment.SpecialFolder.Desktop), "file2.pdf");
PdfReader reader = new PdfReader(existingFile);
byte[] bytes;
using(MemoryStream ms = new MemoryStream()){
using (PdfStamper stamper = new PdfStamper(reader, ms)) {
PdfContentByte cb = stamper.GetOverContent(1);
ColumnText ct = new ColumnText(cb);
ct.SetSimpleColumn(100,100,500,200);
ct.AddElement(new Paragraph("This was added using ColumnText"));
ct.Go();
//Flush the PdfStamper's buffer
stamper.Close();
//Get the raw bytes of the PDF
bytes = ms.ToArray();
}
}
//Do whatever you want with the bytes
//Below I'm writing them to disk but you could also write them to the output buffer, too
using (FileStream fs = new FileStream(newFile, FileMode.Create, FileAccess.Write, FileShare.None)) {
fs.Write(bytes, 0, bytes.Length);
}
The second part of your question title says:
"outputting as content disposition"
If that's what you really want you can do this:
Response.AddHeader("Content-Disposition", "attachment; filename=DESIRED-FILENAME.pdf");
Using a MemoryStream is unnecessary, since Response.OutputStream is available. Your example code is calling NewPage() and not trying to add the text to an existing page of your PDF, so here's one way to do what you asked:
Response.ContentType = "application/pdf";
Response.AddHeader("Content-Disposition", "attachment; filename=itextTest.pdf");
PdfReader reader = new PdfReader(readerPath);
// store the extra text on the last (new) page
ColumnText ct = new ColumnText(null);
ct.AddElement(new Paragraph("Text on a new page"));
int numberOfPages = reader.NumberOfPages;
int newPage = numberOfPages + 1;
// get all pages from PDF "template" so we can copy them below
reader.SelectPages(string.Format("1-{0}", numberOfPages));
float marginOffset = 36f;
/*
* we use the selected pages above with a PdfStamper to copy the original.
* and no we don't need a MemoryStream...
*/
using (PdfStamper stamper = new PdfStamper(reader, Response.OutputStream)) {
// use the same page size as the __last__ template page
Rectangle rectangle = reader.GetPageSize(numberOfPages);
// add a new __blank__ page
stamper.InsertPage(newPage, rectangle);
// allows us to write content to the (new/added) page
ct.Canvas = stamper.GetOverContent(newPage);
// add text at an __absolute__ position
ct.SetSimpleColumn(
marginOffset, marginOffset,
rectangle.Right - marginOffset, rectangle.Top - marginOffset
);
ct.Go();
}
I think you've already figured out that the Document / PdfWriter combination doesn't work in this situation :) That's the standard method for creating a new PDF document.
I attempted several ways to do this, but still cannot get it.
It appears iTextSharp requires a 2 pass situation so that an image appears on top of the text.
So I am attempting to do this using memory streams, but I keep getting errors.
Public Function createDoc(ByRef reqResponse As HttpResponse) As Boolean
Dim m As System.IO.MemoryStream = New System.IO.MemoryStream()
Dim document As Document = New Document()
Dim writer As PdfWriter = iTextSharp.text.pdf.PdfWriter.GetInstance(document, m)
document.Open()
document.Add(New Paragraph(DateTime.Now.ToString()))
document.Add(New Paragraph(DateTime.Now.ToString()))
document.Add(New Paragraph(DateTime.Now.ToString()))
document.Add(New Paragraph(DateTime.Now.ToString()))
document.Add(New Paragraph(DateTime.Now.ToString()))
document.Add(New Paragraph(DateTime.Now.ToString()))
document.Add(New Paragraph(DateTime.Now.ToString()))
document.Close()
writer.Flush()
writer.Flush()
'yes; I get the pdf if this is the last statement
'reqResponse.OutputStream.Write(m.GetBuffer(), 0, m.GetBuffer().Length)
'this statment does not work it says the stream is closed
'm.Position = 0
Dim Reader As PdfReader = New PdfReader(m)
'Dim rm As MemoryStream = New MemoryStream(m.GetBuffer(), 0, m.GetBuffer().Length)
Dim PdfStamper As PdfStamper = New PdfStamper(Reader, reqResponse.OutputStream)
Dim cb As iTextSharp.text.pdf.PdfContentByte = Nothing
cb = PdfStamper.GetOverContent(1)
Dim locMyImage As System.Drawing.Image = System.Drawing.Image.FromStream(zproProduceWhiteImageToCovertBarCodeNumbers())
Dim BImage As iTextSharp.text.Image = iTextSharp.text.Image.GetInstance(locMyImage, iTextSharp.text.BaseColor.CYAN)
Dim overContent As PdfContentByte = PdfStamper.GetOverContent(1)
BImage.SetAbsolutePosition(5, 5)
overContent.AddImage(BImage)
PdfStamper.FormFlattening = True
PdfStamper.Close()
'rm.Flush()
'rm.Close()
'Dim data As Byte() = rm.ToArray()
'reqResponse.Clear()
'Dim finalMs As MemoryStream = New MemoryStream(data)
'reqResponse.ContentType = "application/pdf"
'reqResponse.AddHeader("content-disposition", "attachment;filename=labtest.pdf")
'reqResponse.Buffer = True
'finalMs.WriteTo(reqResponse.OutputStream)
'reqResponse.End()
'Dim data As Byte() = rm.ToArray()
'reqResponse.OutputStream.Write(data, 0, data.Length)
''Response.OutputStream.Write(m.GetBuffer(), 0, m.GetBuffer().Length);
''Response.OutputStream.Flush();
''Response.OutputStream.Close();
''Response.End();
HttpContext.Current.ApplicationInstance.CompleteRequest()
Return True
End Function
reference:
Put text on top of an image?
seach engine reference:
whiteout text on a pdf document by using a image which is the same color as the background pdf
image overlap with itextpdf
itextsharp image on top of the text whiteout
itextsharp place picture on top of text
itextpdf image on top
thanks,
Doug Lubey of Louisiana
You can do this pretty easily. The Document object is a helper object that abstracts away many of the internals of the PDF model and for the most part assumes that you want to flow content and that text would go above images. If you want to get around this you can talk directly the PdfWriter object instead. It has two properties, DirectContent and DirectContentUnder that both have methods named AddImage() that you can use to set an absolute position on an image. DirectContent is above existing content and DirectContentUnder is below it. See the code for an example:
You appear to be doing this on the web so you'll need to adapt this to whatever stream you are using but that should be pretty easy.
One note, NEVER call GetBuffer() on a MemoryStream, ALWAYS use ToArray(). The former method includes uninitialized bytes that will give you potentially corrupt PDFs.
''//File that we are creating
Dim OutputFile As String = System.IO.Path.Combine(Environment.GetFolderPath(Environment.SpecialFolder.Desktop), "Test.pdf")
''//Image to place
Dim SampleImage As String = System.IO.Path.Combine(Environment.GetFolderPath(Environment.SpecialFolder.Desktop), "SampleImage.jpg")
''//Standard PDF creation setup
Using FS As New FileStream(OutputFile, FileMode.Create, FileAccess.Write, FileShare.None)
Using Doc As New Document(PageSize.LETTER)
Using writer = PdfWriter.GetInstance(Doc, FS)
''//Open the document for writing
Doc.Open()
''//Add a simple paragraph
Doc.Add(New Paragraph("Hello world"))
''//Create an image object
Dim Img = iTextSharp.text.Image.GetInstance(SampleImage)
''//Give it an absolute position in the top left corner of the document (remembering that 0,0 is bottom left, not top left)
Img.SetAbsolutePosition(0, Doc.PageSize.Height - Img.Height)
''//Add it directly to the raw pdfwriter instead of the document helper. DirectContent is above and DirectContentUnder is below
writer.DirectContent.AddImage(Img)
''//Close the document
Doc.Close()
End Using
End Using
End Using
I want to create a PdfWriter Object and set Events for Header and Footer.
The problem is it works if I create a new PDF. But my problem is I already have a PDF in Output Stream. Please find my sample code below.
Document document = new Document();
try {
// step 2:
FileInputStream is = new FileInputStream("D://2.pdf");
int nRead;
byte[] data = new byte[16384];
ByteArrayOutputStream buffer = new ByteArrayOutputStream();
while ((nRead = is.read(data, 0, data.length)) != -1) {
buffer.write(data, 0, nRead);
}
buffer.flush();
PdfWriter writer = PdfWriter.getInstance(document,buffer);
writer.setViewerPreferences(PdfWriter.PageLayoutTwoColumnLeft);
writer.setPageEvent(new DossierPortalUtil());
document.setMargins(36, 36, 54, 72);
// step 3:
document.open();
document.add( new Chunk("testing"));
} catch (Exception de) {
de.printStackTrace();
}
finally{
document.close();
}
If I comment the line
document.add( new Chunk("testing"));
I get an exception
Exception in thread "main" ExceptionConverter: java.io.IOException: The document has no pages.
Without commenting there are no exceptions but it doesnt add the Header and Footer. Any clues are highly appreciated.
Regards,
Tina
enter code here
Yep.
You're trying to modify an existing PDF with PdfWriter, when you should be using PdfStamper.
Adding text with a stamper is Far Less Trivial than doing so with PdfWriter and a Document.
You need to create a ColumnText object, and get a PdfContentByte by calling myStamper.getOverContent(pageNum).
You add the paragraphs/chunks/etc to the ColumnText, and pass it the PdfContentByte (and some positional parameters) to draw the text.
Alternatively, you can create a separate PDF with your text (and anything else), then use PdfStamper & PdfImportedPage to import those pages and write them over top of the existing ones. PDF page backgrounds are transparent until you draw something over them, so the text (and stuff) will appear over top of the existing page. This is noticeably less efficient, as the second document has to be converted to a byte array in PDF syntax (if you're using a ByteArrayOutputStream instead of writing to a file, which would be even slower), parsed again, and then added to the original doc and written out a second time.
It's worth a little extra effort to use ColumnText.
You'll also need to write your header and footer directly with PdfContentByte calls, but you have to do that already within your PdfPageEvent, so those changes should be quite simple.