![](/img/trans.png)
[英]Need help to redirect my one JSP page with prepopulated value in my textbox in another JSP
[英]Hi I need help in streaming image in my JSP page
好的,所以我創建了一個音樂上傳網站,可以上傳OGG音樂。 它還集成了音頻標記器。 我還將專輯封面作為字符串放入到數據庫中。
現在,我想在我的JSP中顯示該字符串(代表我的專輯封面):
@WebServlet(name = "LoadAlbumArt", urlPatterns = { "/LoadAlbumArt" })
public class LoadAlbumArt extends HttpServlet {
/**
* Processes requests for both HTTP <code>GET</code> and <code>POST</code> methods.
* @param request servlet request
* @param response servlet response
* @throws ServletException if a servlet-specific error occurs
* @throws IOException if an I/O error occurs
*/
protected void processRequest(HttpServletRequest request,
HttpServletResponse response) throws ServletException, IOException {
response.setContentType("image/jpg");
try {
OutputStream outputStream = response.getOutputStream();
DBConnector bConnector = new DBConnector();
PreparedStatement preparedStatement = bConnector
.Connect("SELECT * FROM devwebmp3.musicdatabase where musicno = ?");
preparedStatement.setInt(1,
Integer.parseInt(request.getParameter("musicno")));
ResultSet resultSet = preparedStatement.executeQuery();
Blob blob = null;
String imagestring = null;
while (resultSet.next()) {
imagestring = resultSet.getString("albumart");
}
//BufferedImage bi = ImageIO.read(ImageIO.createImageInputStream(new ByteArrayInputStream(Base64Coder.decode(imagestring.toCharArray()))));
//outputStream.write(blob.getBytes(1, (int) blob.length()));
byte[] hello = Base64Coder.decode(imagestring);
//ImageIO.write(bi, "jpg", outputStream);
//System.out.println("byte" + hello);
outputStream.write(hello);
outputStream.flush();
outputStream.close();
} catch (Exception e) {
// ...
}
// ...
}
}
另外,這是java servlet頁面:
src=<%="\"LoadAlbumArt?musicno="+request.getParameter("musicno") +"\""%>>
首先,在哪里調用此processRequest(..)
方法?
您確定在該servlet的doGet(..)
方法中包括對processRequest(..)
的調用,如下所示:
public void doGet(HttpServletRequest req, HttpServletResponse resp)
throws ServletException, IOException {
processRequest(req,resp);
}
您是否通過請求檢查了已知記錄的輸出
http://.../LoadAlbumArt?musicno=1
您的Servlet是否正確響應JPEG圖像? 如果不是,則應檢查Servlet代碼。
另外,將“視圖”頁面中的表達式更改為此:
<img src="/LoadAlbumArt?musicno=${param.musicno}" />
那些JSP腳本和表達式( <% %>
和<%= %>
)現在是古董,您除非有一些舊代碼可以復活,否則永遠不要使用它們。
您沒有提供有關數據庫表BLOB字段的足夠詳細信息,即使您的問題中包含隨機注釋的代碼,也很難決定是否使用它們。
聲明:本站的技術帖子網頁,遵循CC BY-SA 4.0協議,如果您需要轉載,請注明本站網址或者原文地址。任何問題請咨詢:yoyou2525@163.com.