java - 我无法多次显示照片 Blob

Question

我有一个包含每个人照片的数据库。我有一个类展示人们的照片。当该类首先运行时，它会将照片存储在本地，然后另一个方法获取它并显示它。问题是该类只能在第一次正确运行!每个其他名称选择都会显示第一张图片。请帮我确定这是在哪里发生的!

这是我的类(class):

public class Profile extends JFrame {

    int x;
    JLabel label;
    Image img;
    ImageIcon pic;
    JPanel panel;
    private JTextPane namepanel = new JTextPane();
    private JLabel namelabel = new JLabel();
    private JLabel lastnamelabel = new JLabel();
    private JTextPane lastnamepanel = new JTextPane();
    ResultSet resultSet;
    private JButton add = new JButton();
    private JButton remove = new JButton();

    public Profile() {
        try {

            //getData(x);
            //showImage();
            //jbInit();
        } catch (Exception e) {
            e.printStackTrace();
        }


    }


    public void getData(int p_id) throws Exception {



        Login login = new Login();
        String url = "jdbc:oracle:thin:@localhost:1521:ORCL";
        String username = login.getUsername();
        String password = login.getPassword();
        Connection conn = null;

        try {

            Class.forName("oracle.jdbc.driver.OracleDriver");
            conn = DriverManager.getConnection(url, username, password);
            System.out.println("At the profile class id = " + p_id);
            String sql = "SELECT foto, name, surname FROM criminals WHERE id = " + p_id;
            System.out.println(sql);
            PreparedStatement stmt = conn.prepareStatement(sql);
            resultSet = stmt.executeQuery();

            while (resultSet.next()) {
                namepanel.setText(resultSet.getString(2));
                lastnamepanel.setText(resultSet.getString(3));

                File image = new File("java.jpg");
                FileOutputStream fos = new FileOutputStream(image);
                byte[] buffer = new byte[256];


                // Get the binary stream of our BLOB data

                InputStream is = resultSet.getBinaryStream(1);
                int bytes = 0;
                while ((bytes = is.read(buffer)) > 0) {


                    fos.write(buffer, 0, bytes);
                }
                showImage();

                fos.close();

            }
        } catch (SQLException e) {
            e.printStackTrace();
        } finally {
            if (conn != null && !conn.isClosed()) {
                conn.close();
            }
        }


    }


    public void showImage() throws Exception {

        this.getContentPane().removeAll();
        img = null;
        img = new ImageIcon("java.jpg").getImage();
        pic = null;
        pic = new ImageIcon(img);
        label = new JLabel("", pic, JLabel.CENTER);
        panel = new JPanel(new BorderLayout());
        panel.setBounds(new Rectangle(0, 0, 340, 310));
        namepanel.setBounds(new Rectangle(340, 30, 295, 35));
        namelabel.setText("Name");
        namelabel.setBounds(new Rectangle(340, 0, 295, 30));
        lastnamelabel.setText("Surname");
        lastnamelabel.setBounds(new Rectangle(340, 65, 295, 30));
        lastnamepanel.setBounds(new Rectangle(340, 105, 295, 35));
        add.setText("add");
        add.setBounds(new Rectangle(440, 175, 255, 40));
        remove.setText("remove");
        remove.setBounds(new Rectangle(440, 240, 255, 35));
        panel.add(label, null);
        panel.add(label, BorderLayout.CENTER);
        this.getContentPane().setLayout(null);
        this.setSize(new Dimension(1148, 336));
        this.getContentPane().add(remove, null);
        this.getContentPane().add(add, null);
        this.getContentPane().add(lastnamepanel, null);
        this.getContentPane().add(lastnamelabel, null);
        this.getContentPane().add(namelabel, null);
        this.getContentPane().add(namepanel, null);
        this.getContentPane().add(panel, null);


    }

Answer 1

您使用的方式不是使用准备好的语句的方式。使用这种方式

        String sql = "SELECT foto, name, surname FROM criminals WHERE id = ?" ;

        PreparedStatement stmt = conn.prepareStatement(sql);

stmt.setInt(1,p_id);