Question

我在显示从JFrame上的数据库检索的图像时遇到问题。这是我将使用的， .........

     try
               {
               Class.forName("com.mysql.jdbc.Driver");
            Connection con=DriverManager.getConnection("jdbc:mysql://localhost:3306/studio","root","");  
            Statement st=con.createStatement();   
            ResultSet rs = st.executeQuery( "select  image  from photo_instn where cust_id='2'") ;
            while(rs.next()) 
            {
            byte[] imagedata = rs.getBytes("image") ;
            Image img = Toolkit.getDefaultToolkit().createImage(imagedata);
            ImageIcon icon =new ImageIcon(img);
            JLabel lPhoto = new JLabel(icon) ;
            setLayout(null);                              // BYTES TO IMAGE                                                                      
            System.out.println("Inside");
            System.out.println(lPhoto);
            this.add(lPhoto) ;
            lPhoto.setBounds(200,20,300,400); 
  }
}

这段代码没有问题。但是图片没有显示在框架上...... 请帮我解决这个问题....

Answer 1

import java.awt.*;
import java.sql.*;

import javax.swing.*;

public class DisplayImage extends JFrame {

Connection connection = null;
PreparedStatement statement = null;

ResultSet result;

public DisplayImage() {
    super("Image Display");
    setSize(600, 600);
    connection = getConnection();
    try { // table name:image and second image is field name
        statement = connection
                .prepareStatement("select image from  image where id = 1");
        result = statement.executeQuery();

        byte[] image = null;
        while (result.next()) {
            image = result.getBytes("image");

        }
        Image img = Toolkit.getDefaultToolkit().createImage(image);
        ImageIcon icon = new ImageIcon(img);
        JLabel lPhoto = new JLabel();
        lPhoto.setIcon(icon);
        add(lPhoto);

    } catch (SQLException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    }

    setVisible(true);
}

public Connection getConnection() {
    Connection connection = null;

    try {
        Class.forName("com.mysql.jdbc.Driver");
        connection = DriverManager.getConnection(
                // user name:root and password:blank
                "jdbc:mysql://localhost:3306/insertRetriveImages", "root",
                "");

    } catch (Exception e) {
        System.out.println("Error Occured While Getting the Connection: - "
                + e);
    }
    return connection;
}

public static void main(String[] args) {
    new DisplayImage();
}
}

Answer 2

尝试在

之后将this.setVisible(true)添加到您的代码中

this.add（lPhoto）;

Answer 3

 Class.forName("com.mysql.jdbc.Driver");
            Connection  con= DriverManager.getConnection("jdbc:mysql://localhost:3306/vodafonecare","root","root");
            PreparedStatement ps=con.prepareStatement("select * from photo");
            ResultSet rs=ps.executeQuery();
            if(rs.next()){
                rs.next();
                 rs.next();
            Blob b=rs.getBlob(3);
            byte bt[]=b.getBytes(1,(int)b.length());
             Image img = Toolkit.getDefaultToolkit().createImage(bt);
             photoL.setIcon(new ImageIcon(img));

Answer 4

1从您在代码中检索byte[]，然后

InputStream in = new ByteArrayInputStream(imageInByte);
BufferedImage bImageFromConvert = ImageIO.read(in);

2在JFrame上表示该图像

boolean Graphics.drawImage(Image img, 
                           int x, int y,
                           ImageObserver observer);

另见

Drawing an Image

Answer 5

我们不知道如何使用此代码的上下文。

通常在从GUI添加/删除组件后，您需要使用：

panel.revalidate();
panel.repaint();

如何在JFrame上显示从mysql检索到的图像

5 个答案: