如何从数据库中检索数据并在java中以pdf格式显示

Question

1. 我想以pdf文件格式显示存储在数据库中的数据
2. 我已经显示在网页中，而不是我想显示在 pdf 中。下面是我的代码，我用的是 MySQL 数据库

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public class StockReceiptReturnQuery extends HttpServlet {

    public void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        response.setContentType("text/html");
        PrintWriter out = response.getWriter();

        String receiptNo = request.getParameter("ReceiptNo");
        int Rno = Integer.parseInt(receiptNo);

        try {
            Class.forName("com.mysql.jdbc.Driver");
            Connection con = DriverManager.getConnection("jdbc:mysql://localhost:3306", "root", "dinga");
            PreparedStatement ps = con.prepareStatement("select * from project.stockreceiptreturn WHERE ReceiptNO =?");
            ps.setInt(1, Rno);
            out.print("<center><table width=25% border=1></center>");
            out.print("<center><h1>StockReceiptReturnQuery:</h1></center>");
            ResultSet rs = ps.executeQuery();
            /* Printing column names */
            ResultSetMetaData rsmd = rs.getMetaData();
            while (rs.next()) {
                out.print("<tr>");
                out.print("<td>" + rsmd.getColumnName(1) + "</td>");
                out.print("<td>" + rs.getInt(1) + "</td></tr>");
                out.print("<tr><td>" + rsmd.getColumnName(2) + "</td>");
                out.print("<td>" + rs.getString(2) + "</td></tr>");
                out.print("<tr><td>" + rsmd.getColumnName(3) + "</td>");
                out.print("<td>" + rs.getString(3) + "</td></tr>");
                out.print("<tr><td>" + rsmd.getColumnName(4) + "</td>");
                out.print("<td>" + rs.getString(4) + "</td></tr>");
                out.print("<tr><td>" + rsmd.getColumnName(5) + "</td>");
                out.print("<td>" + rs.getString(5) + "</td></tr>");
                out.print("<tr><td>" + rsmd.getColumnName(6) + "</td>");
                out.print("<td>" + rs.getString(6) + "</td></tr>");
                out.print("<tr><td>" + rsmd.getColumnName(7) + "</td>");
                out.print("<td>" + rs.getInt(7) + "</td></tr>");
                out.print("<tr><td>" + rsmd.getColumnName(8) + "</td>");
                out.print("<td>" + rs.getInt(8) + "</td></tr>");
                out.print("<tr><td>" + rsmd.getColumnName(9) + "</td>");
                out.print("<td>" + rs.getString(9) + "</td></tr>");
                out.print("<tr><td>" + rsmd.getColumnName(10) + "</td>");
                out.print("<td>" + rs.getInt(10) + "</td></tr>");
                out.print("<tr><td>" + rsmd.getColumnName(11) + "</td>");
                out.print("<td>" + rs.getString(11) + "</td></tr>");
                out.print("<tr><td>" + rsmd.getColumnName(12) + "</td>");
                out.print("<td>" + rs.getDouble(12) + "</td></tr>");
                out.print("<tr><td>" + rsmd.getColumnName(13) + "</td>");
                out.print("<td>" + rs.getDouble(13) + "</td></tr>");
                out.print("<tr><td>" + rsmd.getColumnName(14) + "</td>");
                out.print("<td>" + rs.getInt(14) + "</td></tr>");
                out.print("<tr><td>" + rsmd.getColumnName(15) + "</td>");
                out.print("<td>" + rs.getInt(15) + "</td></tr>");
                out.print("<tr><td>" + rsmd.getColumnName(16) + "</td>");
                out.print("<td>" + rs.getDouble(16) + "</td></tr>");
                out.print("<tr><td>" + rsmd.getColumnName(17) + "</td>");
                out.print("<td>" + rs.getDouble(17) + "</td></tr>");
                out.print("<tr><td>" + rsmd.getColumnName(18) + "</td>");
                out.print("<td>" + rs.getDouble(18) + "</td></tr>");
                out.print("<tr><td>" + rsmd.getColumnName(19) + "</td>");
                out.print("<td>" + rs.getDouble(19) + "</td></tr>");
                out.print("<tr><td>" + rsmd.getColumnName(20) + "</td>");
                out.print("<td>" + rs.getString(20) + "</td></tr>");
                out.print("<tr><td>" + rsmd.getColumnName(21) + "</td>");
                out.print("<td>" + rs.getInt(21) + "</td></tr>");
                out.print("<tr><td>" + rsmd.getColumnName(22) + "</td>");
                out.print("<td>" + rs.getString(22) + "</td></tr>");
                out.print("<tr><td>" + rsmd.getColumnName(23) + "</td>");
                out.print("<td>" + rs.getInt(23) + "</td></tr>");
                out.print("<tr><td>" + rsmd.getColumnName(24) + "</td>");
                out.print("<td>" + rs.getInt(24) + "</td></tr>");

            }
            out.print("</table>");

        } catch (Exception e2) {
            e2.printStackTrace();
        }

        finally {
            out.close();
        }
    }
}

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• 运行 pgm 后我退出了

Answer 1

我建议使用某种 pdf 生成器库，这将允许您使用您的数据创建您喜欢的样式的 PDF。

通过 Google 搜索获得的库示例是 PdfBox https://pdfbox.apache.org/，但请随意使用您自己的。

您所做的一般方法是以编程方式创建一个 Pdf 文档并用您的数据填充它。通常应该有方法以您想要的格式设置 Pdf 的样式（实现将取决于您使用的库）。

您需要将文件保存在某处（无论是在您的服务器上还是在云平台上）以允许用户下载 pdf。然后在网页上将下载链接呈现给用户。