GAE 从数据存储中读取

Question

我想 return 来自 Datastore 的 myHighscores：即：保罗，1200 汤姆，1000 凯文，800

private void returnHighscores(HttpServletResponse resp, String game, int max) throws IOException {
    DatastoreService datastore = DatastoreServiceFactory.getDatastoreService();
    Key gameKey = KeyFactory.createKey("game", game);
    Query query = new Query("highscore", gameKey);
    query.addSort("points", Query.SortDirection.DESCENDING);
    List<Entity> highscores = datastore.prepare(query).asList(FetchOptions.Builder.withLimit(max));

    for(Entity e : highscores) {
        resp.getWriter().println(e.getProperty("name") + "," + e.getProperty("points"));
    }
}

它正在运行 :)！但是当我想阅读 returned Highscores 并将字符串添加到 textView 时：

AndroidHttpClient client = AndroidHttpClient.newInstance("Mueckenfang");
        HttpPost request = new HttpPost(HIGHSCORE_SERVER_BASE_URL + "?game=" + HIGHSCORESERVER_GAME_ID);

        HttpResponse response = client.execute(request);
        HttpEntity entity = response.getEntity();
        InputStreamReader reader = new InputStreamReader(entity.getContent(), "utf-8");
        int c = reader.read();
        while (c > 0) {

            highscores += (char) c;
            c = reader.read();
        }
        TextView tv = (TextView) findViewById(R.id.highscoreTv);
        tv.setText(highscores);

我只得到一些 HTML 代码，例如：

><html><head><meta http-euiv="content-type"content="text/html;charset=utf-8"><title>405 GTTP method POST is....

但我想要 Paul,1200 Tom,1000 Kevin 800 等等

Answer 1

HttpPost 不接受查询参数，就像 "?game=" + HIGHSCORESERVER_GAME_ID.

您需要将这些值作为

传递

AndroidHttpClient client = AndroidHttpClient.newInstance("Mueckenfang");
HttpPost request = new HttpPost(HIGHSCORE_SERVER_BASE_URL);
List<NameValuePair> nameValuePairs = new ArrayList<NameValuePair>(1);  
nameValuePairs.add(new BasicNameValuePair("game", String.valueOf(HIGHSCORESERVER_GAME_ID)));    
request.setEntity(new UrlEncodedFormEntity(nameValuePairs)); 
HttpResponse response = client.execute(request);
HttpEntity entity = response.getEntity();

Answer 2

问题是您在 appengine 上的处理程序仅支持 http 'GET'（我认为您只覆盖了 doGet）但您使用的是来自客户端的 'POST'。将客户端的 http 方法更改为 'GET'.

GAE 从数据存储中读取

GAE Reading from Datastore

android

google-app-engine

google-cloud-datastore