Question

我正在从DB中读取byte[]并将其转换为缓冲图像。

当我尝试显示图像时，我得到NullPointerException。

以下是我坚持使用的代码部分：

        conn = access.getCon();
        sql = "select doc_size, mime_type_id, doc from endo_scope_doc where endo_scope_val_id ='"+idToProcess+"'";
        stmt = conn.prepareStatement(sql);
        ResultSet resultSet = stmt.executeQuery();
        while (resultSet.next()) {
            doc_size = resultSet.getLong(1);
            mime_type_id = resultSet.getInt(2);
            doc = resultSet.getBytes(3);
        }
    } catch (Exception ex) {
        System.out.println(this.getClass().getName()+"."+ex.getStackTrace()[0].getMethodName()+" 4: "+ ex);
        ex.printStackTrace();
        throw new Exception("Cannot execute data retrieval for photo with SQL: "+sql,ex);
    }

        BufferedImage bufferedImage = null;
          try {
        bufferedImage = ImageIO.read(new ByteArrayInputStream(doc));
    } catch (IOException e) {
        e.printStackTrace();
    }

        Image jpeg = Image.getInstance(bufferedImage, null);
        jpeg.scalePercent(40);
        jpeg.setAlignment(Image.LEFT);
        PdfPCell photoCell = new PdfPCell(jpeg);

iText使用com.lowagie.text.Image而非java.awt.Image，因此我无法找到将BufferedImage转换为Image的方法。

这是错误：

java.lang.NullPointerException
at java.awt.image.PixelGrabber.<init>(Unknown Source)
at com.lowagie.text.Image.getInstance(Unknown Source)
at com.lowagie.text.Image.getInstance(Unknown Source)
at iwa.printScopeValPDF.doServlet(printScopeValPDF.java:211)
at iwa.printScopeValPDF.doGet(printScopeValPDF.java:277)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:627)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:729)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(

以iText pdf显示缓冲图像

0 个答案: