jsp从数据库读取图片

CREATE TABLE images (
    id INT PRIMARY KEY,
    image_data BLOB
);

<%@ page import="java.sql.*" %>
<%@ page contentType="image/jpeg" %>
<%
    int imageId = Integer.parseInt(request.getParameter("id"));
    byte[] imageData = getImageFromDatabase(imageId);
    if (imageData != null) {
        out.clear();
        out = pageContext.pushBody();
        response.getOutputStream().write(imageData);
    }
%>

import java.sql.*;

public class ImageDAO {
    private Connection getConnection() throws SQLException {
        // 这里替换为你的数据库连接信息
        String url = "jdbc:mysql://localhost:3306/your_database";
        String user = "your_username";
        String password = "your_password";
        return DriverManager.getConnection(url, user, password);
    }

    public byte[] getImageFromDatabase(int id) {
        String sql = "SELECT image_data FROM images WHERE id = ?";
        try (Connection conn = getConnection();
             PreparedStatement pstmt = conn.prepareStatement(sql)) {
            pstmt.setInt(1, id);
            ResultSet rs = pstmt.executeQuery();
            if (rs.next()) {
                return rs.getBytes("image_data");
            }
        } catch (SQLException e) {
            e.printStackTrace();
        }
        return null;
    }
}