從Oracle數據庫中的Blob列在JLabel上顯示圖像

Question

如何從Oracle數據庫中的Blob列在JLabel上顯示圖像？

您好，我已經努力工作了好幾天，試圖弄清楚如何在oracle數據庫中的blob列上顯示jLabel上的圖像，但是所有努力似乎不足以產生期望的結果。 問題是標簽顯示的是深色的東西，例如背景。 我花了很多時間在谷歌上搜索，還在堆棧溢出中進行搜索，但是，可用資源並沒有使我度過難關。請幫助我！ 謝謝。 下面是我正在使用的代碼段...

    private void studentIdItemStateChanged(java.awt.event.ItemEvent evt)          {                                           
        String id = (String)studentId.getSelectedItem();


        try{


             con = DriverManager.getConnection("jdbc:odbc:test", "SYSTEM", "VICTOR");
             stmt = con.createStatement();
             result = stmt.executeQuery("select * from STUDENTDBASE.STUDENT where   Student_Id = '" + id + "' ");
             result = stmt.getResultSet();

             while (result.next()){
                 surname.setText(result.getString("Surname"));
                 firstName.setText(result.getString("First_Name"));
                 otherNames.setText(result.getString("Other_Names"));
                 phoneNumber.setText(result.getString("Mobile_Number"));
                 dob.setText(result.getString("Date_Of_Birth"));
                 gender.setText(result.getString("Gender"));
                 address.setText(result.getString("Address"));
                 state.setText(result.getString("State"));
                 lga.setText(result.getString("Lga"));

                }
             result.close();


             PreparedStatement ps;           
             con = DriverManager.getConnection("jdbc:odbc:test", "SYSTEM", "VICTOR");
             ps = (PreparedStatement) con.prepareStatement("select Image from STUDENTDBASE.STUDENT_Images where STUDENT_ID = '" + id + "' ");
             result2 = ps.executeQuery();

             while (result2.next()){


                InputStream in = result2.getBinaryStream("Image");


               BufferedImage im = ImageIO.read(in); 
               BufferedImage outimage = new BufferedImage(image.getWidth(), image.getHeight(), BufferedImage.TYPE_INT_RGB);
               Graphics2D g = outimage.createGraphics();

                float xScale = (float)image.getWidth() / outimage.getWidth();
                float yScale = (float)image.getHeight() / outimage.getHeight();
                AffineTransform at = AffineTransform.getScaleInstance(xScale,yScale);
                g.drawRenderedImage(im,at);
                g.dispose();
                Image scaledImage = outimage.getScaledInstance(image.getWidth(), image.getHeight(), Image.SCALE_SMOOTH);
                ImageIcon icon = new ImageIcon(scaledImage);
                image.setIcon(icon);
                image.revalidate();
                basicDetails.revalidate();
                }
             result2.close();
             con.close();
   }
   catch(SQLException d){
       JOptionPane.showMessageDialog(null, "Error is due to " + d.getMessage(), "Error message from database", JOptionPane.ERROR_MESSAGE);
   }
       catch(IOException io){
       JOptionPane.showMessageDialog(null, "Error is due to " + io.getMessage(), "Error message from database", JOptionPane.ERROR_MESSAGE);
        }







//Insert Student image into database
            url = "jdbc:odbc:test";
            String query1 = "insert into STUDENTDBASE.STUDENT_Images (Student_Id, Image, Image_Path, Image_Size)values('" + counterValue + "', ?, '" + path + "', '" + stringLength + "' ) ";
            con = DriverManager.getConnection(url, "SYSTEM", "VICTOR");
            PreparedStatement ps=con.prepareStatement(query1);
            FileInputStream fin=new FileInputStream(file);
            ps.setString(1, file.getName());
            ps.setBinaryStream(2, fin, file.length());
            ps.executeUpdate();

Answer 1

由於您使用的PreparedStatement錯誤，因此從未插入圖像。 你要用嗎？ 所有參數，而不僅僅是其中一個。