如何在java netbeans中显示从ms访问jpanel的图像 [英] How to show an image from ms access to jpanel in java netbeans

问题描述

我使用的代码：

private void okActionPerformed(java.awt.event.ActionEvent evt)        
{                                   
    try {
        String Update = name.getText();

        Class.forName("sun.jdbc.odbc.JdbcOdbcDriver");
        Connection connection = DriverManager.getConnection("jdbc:odbc:NewPData");
        PreparedStatement psmnt = connection.prepareStatement("SELECT Image FROM Table1 where Name='" + Update + "'");
        ResultSet rs = psmnt.executeQuery();
        Blob blob = rs.getBlob("Image");
        int b;
        InputStream bis = rs.getBinaryStream("Image");

        FileOutputStream f = new FileOutputStream("Image.jpg");
        while ((b = bis.read()) >= 0) {
            f.write(b);
        }
        f.close();
        bis.close();

        icon = new ImageIcon(blob.getBytes(1L, (int) blob.length()));

        lblImage.setIcon(icon);

    } catch (ClassNotFoundException e) {
        e.printStackTrace();
    } catch (Exception e) {
        e.printStackTrace();
    }
}

例外显示：

       java.lang.UnsupportedOperationException

我首先以ms访问存储图像，现在我想在标签上显示它。请帮助。

I have first stored the image in ms access and now I want to show it on a label. Please help.

推荐答案

这部分代码没有意义。

Blob blob = rs.getBlob("Image");
int b;
InputStream bis = rs.getBinaryStream("Image");

FileOutputStream f = new FileOutputStream("Image.jpg");
while ((b = bis.read()) >= 0) {
    f.write(b);
}
f.close();
bis.close();

icon = new ImageIcon(blob.getBytes(1L, (int) blob.length()));

您基本上从结果集中读取BLOB到文件，然后再次尝试读取它以构建您的图片。你可能已经耗尽了这条小溪。

You basically read the BLOB from result set to a file and then try and read it again to construct your image. It's possible that you've exhausted the stream.

为什么不只是阅读图片？

Why not just read the image?

icon = new ImageIcon("Image.jpg");

更好的是，为什么不利用 ImageIO API并直接读取流，是否需要写出临时文件？

Better yet, why not take advantage of the ImageIO API and read the stream directly, for-going the need to write out a temp file?

BufferedImage image = ImageIO.read(bis); 
icon = image == null ? null : new ImageIcon(image);

这篇关于如何在java netbeans中显示从ms访问jpanel的图像的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！