以编程方式在android中创建一个pdf文件并在其中写入 [英] Creating a pdf file in android programmatically and writing in it

问题描述

我正在尝试在我的应用程序中创建一个 pdf 文件，将其保存在外部存储中并打开它.保存文件对我来说不是问题，打开文件也不是问题，我的问题是创建一个文件并在其中写入.因此，在网上进行了一些研究后，我发现了以下方法:

I'm trying to create a pdf file inside my app, save it on the external storage the open it. Saving a file isn't an issue for me, nor is opening one, my issue is with creating one and writing in it. So after some research online I found the following way of doing it:

File file = new File(directoryName, fileName);

// Creating output stream to write in the newly created file
FileOutputStream fOut = null;

try {
    fOut = new FileOutputStream(file);
} catch (FileNotFoundException e) {
    e.printStackTrace();
}

// Creating a new document
Document document = new Document(PageSize.A4, 50, 50, 50, 50);

try {
    PdfWriter.getInstance(document, fOut);

    // Open the document for writing
    document.open();

    // Write in the document
    document.add(new Paragraph("Hello world"));
    document.close();

} catch (DocumentException de) {
    System.err.println(de.getMessage());
}

运行我的应用程序并执行上面的代码后，出现以下错误:

Upon running my app and executing the code above, I get the following error:

java.lang.NoClassDefFoundError: Failed resolution of: Ljava/awt/Color;

有人知道我的代码有什么问题吗，或者知道另一种肯定适用于创建和编写 pdf 文件的方法吗?

Would someone know what's the issue with my code, or of another way that is sure to work for creating and writing a pdf file ?

谢谢！

推荐答案

很明显我使用的代码与 android 不兼容，因此我得到了错误.您会在下面找到实际运行的正确代码(用于创建 pdf 文件、在其中放入一些内容、保存并打开新创建的文件):

So apparently the code I was using wasn't compatible with android, hence the error I was getting. Below you'll find the correct code that actually works right (for creating a pdf file, putting some content in it, saving in and the opening the newly created file):

PS:为此，您需要将 iTextG 的 jar 添加到您的项目中:

PS: For this you'll need to add the jar of iTextG to your project:

// Method for creating a pdf file from text, saving it then opening it for display
    public void createandDisplayPdf(String text) {

        Document doc = new Document();

        try {
            String path = Environment.getExternalStorageDirectory().getAbsolutePath() + "/Dir";

            File dir = new File(path);
            if(!dir.exists())
                dir.mkdirs();

            File file = new File(dir, "newFile.pdf");
            FileOutputStream fOut = new FileOutputStream(file);

            PdfWriter.getInstance(doc, fOut);

            //open the document
            doc.open();

            Paragraph p1 = new Paragraph(text);
            Font paraFont= new Font(Font.COURIER);
            p1.setAlignment(Paragraph.ALIGN_CENTER);
            p1.setFont(paraFont);

            //add paragraph to document
            doc.add(p1);    

        } catch (DocumentException de) {
            Log.e("PDFCreator", "DocumentException:" + de);
        } catch (IOException e) {
            Log.e("PDFCreator", "ioException:" + e);
        }
        finally {
            doc.close();
        }

        viewPdf("newFile.pdf", "Dir");
    }

    // Method for opening a pdf file
    private void viewPdf(String file, String directory) {

        File pdfFile = new File(Environment.getExternalStorageDirectory() + "/" + directory + "/" + file);
        Uri path = Uri.fromFile(pdfFile);

        // Setting the intent for pdf reader
        Intent pdfIntent = new Intent(Intent.ACTION_VIEW);
        pdfIntent.setDataAndType(path, "application/pdf");
        pdfIntent.setFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);

        try {
            startActivity(pdfIntent);
        } catch (ActivityNotFoundException e) {
            Toast.makeText(TableActivity.this, "Can't read pdf file", Toast.LENGTH_SHORT).show();
        }
    }

这篇关于以编程方式在android中创建一个pdf文件并在其中写入的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！