Servlet中的iText PDF [英] iText PDF in Servlet

问题描述

所以，我正在使用此代码从我的服务器创建报告PDF文件

So, i'm creating a report PDF file from my server using this code

response.setHeader("Expires", "0");
response.setHeader("Cache-Control", "must-revalidate, post-check=0, pre-check=0");
response.setHeader("Pragma", "public");
response.setContentType("application/pdf");
List<Integer> cartas1 = new ArrayList<Integer>();
DeudorDAO DDAO = new DeudorDAO();
ByteArrayOutputStream baos = new ByteArrayOutputStream();
try {
    baos = DocumentoCartaCobranza.CrearDocumento(
        getServletContext().getRealPath("static/images/pdf_banner.jpg"),
        getServletContext().getRealPath("static/images/firmaJG.png"),
        getServletContext().getRealPath("static/images/firmaAB.jpg"),
        DDAO.getDatosFullDeudores(cartas1)
    );
} catch (DocumentException e) {
    e.printStackTrace();
}
OutputStream os = response.getOutputStream();
baos.writeTo(os);
os.flush();
os.close();

和

public static ByteArrayOutputStream CrearDocumento(
    String imgCabecera,
    String imgFirma,
    String imgAbogado,
    java.util.List<Deudor> carta1) throws DocumentException {
        ByteArrayOutputStream baos = new ByteArrayOutputStream();
        try {
            PdfWriter pdfw = null;
            pdfw = PdfWriter.getInstance( Documento, baos );
            Documento.open();
            for (Deudor D : carta1){
                //Imagen cabecera
                Image imgHead = Image.getInstance(imgCabecera);
                //imgHead.setAbsolutePosition(35, 770);
                imgHead.scaleAbsolute(125, 40);
                Documento.add(imgHead);
                Carta1(D);
                //Imagen Firma
                Image imgSign = Image.getInstance(imgFirma);
                //imgHead.setAbsolutePosition(35, 770);
                imgSign.scaleAbsolute(110, 105);
                Documento.add(imgSign);
                Documento.newPage();
            }
            Documento.close();
        }
        catch(DocumentException e) {
            System.out.println(e.getMessage());
        } catch (MalformedURLException e) {
            System.out.println(e.getMessage());
        } catch (IOException e) {
            System.out.println(e.getMessage());
        }
        return baos;
    }

所以我的servlet调用一个类，它返回一个ByteArrayOutputStream。
到目前为止一切顺利。它有效！

So my servlet call a class and it return a ByteArrayOutputStream. So far so good. It works !

当我调用另一个报告时，问题就开始了...... servlet没有响应。它说：

The problems begins when i call another report ... The servlet doesn't response. It says:

该文件已经关闭。你不能添加任何元素。

并且，在第一次通话时它被关闭了。但这是对不同报告的新要求。

And, of cours it was closed, by the first call. But this is a new call for a diferent report.

我想它有关于PDFWriter的一些内容......

I guess it had something about the PDFWriter...

谢谢!!

编辑！

万一你问：

private static float Espaciado = 15;
private static Document Documento = new Document();

private static void Carta1(Deudor D) throws DocumentException {
        //Cabecera Cuerpo
        Paragraph persona = new Paragraph(); persona.add(Chunk.NEWLINE); persona.add(new Chunk("Señor(a)"));
        persona.add(Chunk.NEWLINE); persona.add(new Chunk(D.getPaciente().getNombre()).append(" ").
                append(D.getPaciente().getApepat()).append(" ").append(D.getPaciente().getApemat()).toString());
        persona.add(Chunk.NEWLINE); persona.add(new Chunk(D.getPaciente().getRut().toString()).append("-").append(D.getPaciente().getDV()).toString());
        persona.add(Chunk.NEWLINE); persona.add(new Chunk(D.getPaciente().getDireccion()+", "+D.getPaciente().getCiudad()+", "+D.getPaciente().getComuna()));
        persona.setAlignment(Element.ALIGN_LEFT);

        Paragraph folio = new Paragraph();
        Chunk c = new Chunk(D.getIngreso().toString()+"-"+D.getDV(), new Font(folio.getFont().getFamily(), 20, Font.BOLD)); c.setUnderline(0.5f, -1.5f); folio.add(c);
        folio.add(Chunk.NEWLINE); folio.add(new Chunk("Ref: Valorización PAM"));
        folio.setAlignment(Element.ALIGN_RIGHT);

        Paragraph cc = new Paragraph(new Chunk("Estimado Paciente:"));
        cc.setAlignment(Element.ALIGN_LEFT); cc.setSpacingAfter(Espaciado);
        //Cuerpo
        Paragraph p2 = new Paragraph(new Chunk("En CLINICA IQUIQUE S.A. bla bla").toString());
        p2.setFirstLineIndent(50); p2.setSpacingAfter(Espaciado); p2.setAlignment(Element.ALIGN_JUSTIFIED);

        Documento.add(persona); Documento.add(folio); Documento.add(cc);
        Documento.add(p2); 
    }

推荐答案

这很简单：你创建一个静态文档：

it is quite simple: you create a static document:

 private static Document Documento = new Document();

然后你打电话给它关闭：

and then you call close on it:

Documento.close();

因此错误是合乎逻辑的。将文档创建为方法属性并将其传递，而不是将其用作静态。在servlet中使用静态字段只对缓存有用，其他任何东西都要求麻烦。

So the error is logical. Create the document as a method property and pass it on instead of using it as static. Using static fields in servlets is only good for caches, anything else is asking for trouble.

这篇关于Servlet中的iText PDF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！