Question

我的应用中存在问题。首先，我将描述它是如何工作的。它向服务器发送请求（这不是我创建的），并且在响应中我得到JSON字符串（它在JSONarray中不是那么大的平均10条记录），在一个参数中有我下载的图片的URL和保存为每个JSON对象的位图。总结一下，我下载了一个类似于：

的JSON

{
    "id":"125", 
    "description":"desc",   
    "type":"type",  
    "state":"state",    
    "date":"2012-09-22 10:40:46.0",
    "lat":"52.321911",
    "lng":"19.464111",
    "author":"user",
    "photo":"GetImage?size=small&id=0",
    "comments":[

    ]
    }

例如，

x 10，然后我从每个对象的URL“照片”图像下载。问题在于执行时间，真的很长，不应该是大数据。这是我如何做到这一点：下载图像的AsyncClass：

private class HttpGetImage extends AsyncTask<Object, Integer, Integer>
    {
        public boolean ready = false;
        public boolean success = false;

        @Override
        protected Integer doInBackground(Object... obj) {
            DefaultHttpClient client = new MyHttpClient(ViewEdit.this);

            HttpGet get = new HttpGet(url+photoUrl);
            HttpResponse getResponse = null;
            try {
                getResponse = client.execute(get);
            } catch (ClientProtocolException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
                ready=true; return null;

            } catch (IOException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
                ready=true; return null;

            }

            HttpEntity responseEntity = getResponse.getEntity();
            BufferedHttpEntity httpEntity = null;
            try {
                httpEntity = new BufferedHttpEntity(responseEntity);
            } catch (IOException e1) {
                // TODO Auto-generated catch block
                e1.printStackTrace();
                ready=true; return null;

            }
            InputStream imageStream = null;
            try {
                imageStream = httpEntity.getContent();
                m_orders.get((Integer)obj[1])
                    .setOrderBitmap(BitmapFactory.decodeStream(imageStream));

                success = true;
            } catch (IOException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
                ready=true; return null;

            } finally {
                try {
                    imageStream.close();
                } catch (IOException e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                    ready=true; return null;

                }
            }

            ready = true;
            return null;
        }
    }

和jsonString的AsyncClass：

private class HttpGetNotifications extends AsyncTask<Double, Integer, Integer>
    {
        public boolean ready = false;
        public boolean success = false;

        @Override
        protected Integer doInBackground(Double... params) 
        {
            DefaultHttpClient client = new MyHttpClient(ViewEdit.this);
            HttpGet get = new HttpGet(url + Double.toString(params[0]) + "&longitude=" + Double.toString(params[1]) + "&radius="+distance);

            HttpResponse getResponse = null;
            try {
                getResponse = client.execute(get);

            } catch (ClientProtocolException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
                ready=true; return null;
            } catch (IOException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
                ready=true; return null;
            }
            HttpEntity responseEntity = getResponse.getEntity();
            String entityContents="";
            try {
                entityContents = EntityUtils.toString(responseEntity);

                loadNotifications(entityContents);
                success = true;
            } catch (ParseException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
                ready=true; return null;

            } catch (IOException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
                ready=true; return null;

            } catch (JSONException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
                ready=true; return null;

            }

            ready = true;
            return null;
        }

        public void loadNotifications(String jsonstring) throws JSONException
        {
            JSONObject jsonResponse = new JSONObject(jsonstring);

            JSONArray notifi = jsonResponse.getJSONArray("notifications");
            for (int i =0, count = notifi.length(); i <count; i++){
                //storage of data
            }       
        }
    }

也许你们有个想法如何优化代码以减少执行时间？

Answer 1

进行一些剖析以找出花时间的东西。在每个AsyncTasks中：

private long time0, time1;
@Override protected void onPreExecute() {
    time0 = System.currentTimeMillis();
}
@Override protected void onPostExecute(HttpResponse response) {
    time1 = System.currentTimeMillis();
long deltaT = (time1 - time0);
Log.d(TAG, "Execute took "+deltaT+"ms");
}

然后从那里开始。

Android的HTTP请求执行时间确实很长

1 个答案: