[jboss-user] [JBoss Seam] - Legacy code: Integrating with existing servlet

[tonylmai]

Hi all,

We have a chart library that we use to serve images for our application. To integrate with our Seam app, we wrote a simple servlet that invokes the library and return a URL of the created image. The library requires a datasource and user ID so I use dependency injection. However, during runtime, the injection objects are all null.

Here is the code for the servlet:

 public class GetChart extends HttpServlet {
  | 
  |     @In("quoteDS")
  |     private ChartDatasource quoteDS;
  | 
  |     @In
  |     private WcLoginSession wcLoginSession;
  |     
  |     protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
  |         try {
  |             writeChart(request, response);
  |         } catch (Exception e) {
  |             e.printStackTrace();
  |         }
  |     }
  | 
  |     private void writeChart(HttpServletRequest request, HttpServletResponse response) throws Exception {
  |         OutputStream out = response.getOutputStream();
  |         try {
  |             response.setContentType("img/png");
  |             ChartCriteria chartCriteria = ChartCriteria.fromRequest(request);
  |             if (chartCriteria != null) {
  |                 writeChart(out, chartCriteria);
  |             }
  |         } finally {
  |             try {
  |                 out.flush();
  |             } catch (IOException e) {
  |                 e.printStackTrace();
  |             }
  |             out.close();
  |         }
  |     }
  | 
  |     private void writeChart(OutputStream out, ChartCriteria chartCriteria) {
  |         Chart chart = new Chart(wcLoginSession.getMyLoginId(), chartCriteria);
  |         try {
  |             chart.build(quoteDS, out);
  |         } catch (Exception e) {
  |             e.printStackTrace();
  |         }
  |     }
  | }
  | 

Why would my injections not working? Is there a better way to do this?

I am running Seam 2.0.0CR2 with JBoss 4.2.1GA.

Thanks in advance for your help.

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