sql如何从oracle检索图像并在java框架中显示

Question

如何从oracle检索图像并在java框架中显示。请寄给我一个样本程序 我正在使用oracle 10G express edition

import javax.swing.*;
import java.awt.event.*;
import java.awt.*;
import java.sql.*;

@SuppressWarnings("serial")
public class Search extends JFrame implements ActionListener {

//Initializing Components
    private JLabel lb, lb1, lb2, lb3, lb4, lb5, lb6;
    private JTextField tf1, tf2, tf3, tf4, tf5;
    private byte s4;
    private JButton btn;
    private Connection con;

    Search() {//Creating Constructor for initializing JFrame components
        //Providing Title
        super("Fetching Student Information");
        lb5 = new JLabel("Enter the Employee id:");
        lb5.setBounds(20, 20, 100, 20);
        tf5 = new JTextField(20);
        tf5.setBounds(130, 20, 200, 20);
        btn = new JButton("Submit");
        btn.setBounds(50, 50, 100, 20);
        btn.addActionListener(this);
        lb = new JLabel("Fetching Employee Information From Database");
        lb.setBounds(30, 80, 450, 30);
        lb.setForeground(Color.red);
        lb.setFont(new Font("Serif", Font.BOLD, 20));
        setVisible(true);
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        lb1 = new JLabel("EmployeeName:");
        lb1.setBounds(20, 120, 100, 20);
        tf1 = new JTextField(50);
        tf1.setBounds(130, 120, 200, 20);
        lb2 = new JLabel("Gender:");
        lb2.setBounds(20, 150, 100, 20);
        tf2 = new JTextField(100);
        tf2.setBounds(130, 150, 200, 20);
        lb3 = new JLabel("DOB:");
        lb3.setBounds(20, 180, 100, 20);
        tf3 = new JTextField(50);
        tf3.setBounds(130, 180, 200, 20);
        lb4 = new JLabel("DOJ:");
        lb4.setBounds(20, 210, 100, 20);
        tf4 = new JTextField(50);
        tf4.setBounds(130, 210, 100, 20);
        lb6 = new JLabel("Photo:");
        lb6.setBounds(550, 10, 100, 100);
        setLayout(null);
        setVisible(true);
        //Add components to the JFrame
        add(lb5);
        add(tf5);
        add(btn);
        add(lb);
        add(lb1);
        add(tf1);
        add(lb2);
        add(tf2);
        add(lb3);
        add(tf3);
        add(lb4);
        add(tf4);
        add(lb6);
        //Set TextField Editable False
        tf1.setEditable(false);
        tf2.setEditable(false);
        tf3.setEditable(false);
        tf4.setEditable(false);
    }

    public void actionPerformed(ActionEvent e) {
        //Create DataBase Coonection and Fetching Records
        try {
            String str = tf5.getText();
            String url = "jdbc:oracle:thin:@localhost:1521:XE";
            String u = "ems2";
            String p = "ems2";
            Class.forName("oracle.jdbc.driver.OracleDriver");
            con = DriverManager.getConnection(url, u, p);
            PreparedStatement st = con.prepareStatement("select * from employee where emp_id=?",);
            st.setString(1, str);
            //Excuting Query
            ResultSet rs = st.executeQuery();
            if (rs.next()) {
                String s = rs.getString("employeename");
                String s1 = rs.getString("dob");
                String s2 = rs.getString("gender");
                String s3 = rs.getString("doj");
                //Sets Records in TextFields.
                tf1.setText(s);
                tf2.setText(s2);
                tf3.setText(s1);
                tf4.setText(s3);
            } else {
                JOptionPane.showMessageDialog(null, "please check your employeeID");
            }
            PreparedStatement ps1 = con.prepareStatement("select * from photo where photoid =?");
            ResultSet rs1 = ps1.executeQuery();
            while (rs.next()) {//now on 1st row  
                Blob b = rs.getBlob(2);//2 means 2nd column data  
                byte barr[] = b.getBytes(1, (int) b.length());//1 means first image
            }
            //Create Exception Handler
        } catch (Exception ex) {
            System.out.println(ex);
        }
    }

//Running Constructor
    public static void main(String args[]) {
        new Search();
    }
}

Answer 1

调用一个查询来检索图像，并使用如下内容

byte[] imgData = null;
 if (rs.next ())
 {
   Blob img  = rs.getBlob(1);
   imgData = img.getBytes(1,(int)img.length());
   BufferedImage image = ImageIO.read(new ByteArrayInputStream(imgData));
   yourJLabelInstance.setIcon(new ImageIcon(image));
 }

yourJLabelInstance是创建并添加到框架中的JLabel