我想从数据库中检索图像并将其显示在jsp页面中。

// 数据库连接配置
String url = "jdbc:mysql://localhost:3306/database";
String username = "username";
String password = "password";

// 从数据库中检索图像数据
String query = "SELECT image_data FROM images WHERE image_id = ?";
try (Connection connection = DriverManager.getConnection(url, username, password);
     PreparedStatement statement = connection.prepareStatement(query)) {
    statement.setInt(1, imageId);
    try (ResultSet resultSet = statement.executeQuery()) {
        if (resultSet.next()) {
            // 获取图像数据
            byte[] imageData = resultSet.getBytes("image_data");

            // 在JSP页面中显示图像
            request.setAttribute("imageData", imageData);
            RequestDispatcher dispatcher = request.getRequestDispatcher("image.jsp");
            dispatcher.forward(request, response);
        } else {
            // 图像不存在或无法检索
            // 处理图像不存在的情况
        }
    }
} catch (SQLException e) {
    // 处理数据库异常
    e.printStackTrace();
}

<%@ page import="java.io.*, java.util.*, javax.servlet.*" %>
<%
  byte[] imageData = (byte[]) request.getAttribute("imageData");

  // 设置响应头
  response.setContentType("image/jpeg");

  // 输出图像数据
  try (ServletOutputStream outputStream = response.getOutputStream()) {
      outputStream.write(imageData);
  } catch (IOException e) {
      e.printStackTrace();
  }
%>