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我有一个使用iText库生成 PDF 文件的 Java 类。现在根据我的需要，我必须将这个生成的 PDF 文件保存到 MySQL 数据库表中，但我不知道该怎么做。

我的担忧是：

  1. 我应该在 PDF 表的 MySQL 列中使用什么数据类型来保存 PDF 文件
  2. 哪个查询将生成的 PDF 文件插入数据库

目前我正在生成 PDF 文件并将其存储到本地磁盘的硬编码文件路径中。

这是我用 Java 生成的 PDF 代码：

OutputStream file = new FileOutputStream(new File("D://timer.pdf"));
Document document = new Document();
PdfWriter.getInstance(document, file);

//Inserting Table in PDF
PdfPTable table = new PdfPTable(3);

PdfPCell cell = new PdfPCell(new Paragraph("Java4s.com"));

cell.setColspan(3);
cell.setHorizontalAlignment(Element.ALIGN_CENTER);
cell.setPadding(10.0f);
cell.setBackgroundColor(new BaseColor(140, 221, 8));

table.addCell(cell);

table.addCell("Name");
table.addCell("Address");
table.addCell("Country");
table.addCell("Java4s");
table.addCell("NC");
table.addCell("United States");
table.setSpacingBefore(30.0f);  // Space Before table starts, like margin-top in CSS
table.setSpacingAfter(30.0f);   // Space After table starts, like margin-Bottom in CSS

//Inserting List in PDF
List list = new List(true, 30);
list.add(new ListItem("Java4s"));
list.add(new ListItem("Php4s"));
list.add(new ListItem("Some Thing..."));

//Text formating in PDF
Chunk chunk = new Chunk("Welecome To Java4s Programming Blog...");
chunk.setUnderline(+1f, -2f);//1st co-ordinate is for line width,2nd is space between
Chunk chunk1 = new Chunk("Php4s.com");
chunk1.setUnderline(+4f, -8f);
chunk1.setBackground(new BaseColor(17, 46, 193));

//Now Insert Every Thing Into PDF Document
document.open();//PDF document opened........                  
document.add(Chunk.NEWLINE);   //Something like in HTML :-)
document.add(new Paragraph("Dear Java4s.com"));
document.add(new Paragraph("Document Generated On - " + newDate().toString()));
document.add(table);
document.add(list);            //In the new page we are going to add list
document.close();

file.close();

System.out.println("Pdf created successfully..");


请帮我。
提前致谢。

4

1 回答 1

5
  1. Datatype that you can use is BLOB.

  2. Convert the PDF file and persist the byte[] array in database.

    private byte[] getByteArrayFromFile(final Document handledDocument) throws IOException {
    final ByteArrayOutputStream baos = new ByteArrayOutputStream();
    final InputStream in = new FileInputStream(handledDocument);
    final byte[] buffer = new byte[500];

    int read = -1;
    while ((read = in.read(buffer)) > 0) {
        baos.write(buffer, 0, read);
    }
    in.close();

    return baos.toByteArray();
}

  3. To insert it into DB If you are using any ORM tools you just have to map the column as blob and the tool will handle it for you. In case you are not using it then you can create a prepared statement. Statement has a method called setBlob() which will be useful. Consider the below example and create a normal insert query with blob column.

    String sql = "INSERT INTO testtable(stringcolumn, blobcolumn) VALUES(?,?)";

PreparedStatement statement = conn.getConnection().prepareStatement(sql);
statement.setLong(1, version);
ByteArrayInputStream bais = new ByteArrayInputStream(getByteArrayFromFile(document));
statement.setBlob(2, bais);          
statement.execute();

conn.commit();
于 2013-11-14T06:46:43.127 回答