Java StringWriter StringBuilder exception at toString

Question

Ok.. this is totally weird. I'm trying to make a http request in android. It works and I can 'build' a string using StringWriter but the code throws an exception at writer.toString(). It makes no difference if I use StringBuilder or StringWriter.

try {
    HttpResponse response = httpClient.execute(httpPost);
    InputStream is = response.getEntity().getContent();
    StringBuilder writer = new StringBuilder();
    //StringWriter writer = new StringWriter();
    int ch;
    while(( ch = is.read()) != -1) { 
        writer.append((char)ch);
    }
    String theString = writer.toString();
    return theString;
} 
catch (Exception e) {
    return e.getMessage();
}

Any ideas?

Answer 1

The problem is that your HTTP thread is attempting to update the UI Thread with the HTTPResponse in a TextView or other such UI element so a CalledFromWrongThreadException is being raised.

Using a Handler or other such mechanism to redirect to the UI Thread for the UI update will solve your problem.