java-IntentService冻结了我的应用程序用户界面
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在我的应用程序中,我正在使用Intentservice从服务器获取数据,并将获取的数据存储到本地sqlite db中.我正在使用5 IntentService来获取并填充五个表.每个意向服务的数据最多可包含300行.我该怎么办?
IntentService代码:
public class SendBpRecordServer extends IntentService {
DbHelper dbHelper;
public static final String TAG="BP Service";
public JSONObject finalData;
public SendBpRecordServer() {
super("BP");
dbHelper=new DbHelper(this);
Log.i("In Constructor",TAG);
}
@Override
protected void onHandleIntent(Intent intent) {
String recName=intent.getStringExtra("nameTag");
if (recName.equals("fetch"))
{
Log.i("Send Data","Yes");
fetchDatFromServer();
ResultReceiver resultReceiver=intent.getParcelableExtra("receiverTagBP");
Log.d("BP Reseult ",resultReceiver.toString());
Bundle bun= new Bundle();
bun.putBoolean("Process_Complete_bp",true);
resultReceiver.send(2, bun);
}
else {
Log.i("Inside Service PUT BP ","Yes");
dataCollected();
}
}
private void fetchDatFromServer() {
Response.Listener listener=new Response.Listener<JSONObject>()
{
@Override
public void onResponse(JSONObject response) {
Log.i("Json Array Response", response.toString());
try
{
Boolean responseStatusCondition=response.getBoolean("success");
if (responseStatusCondition)
{
JSONArray jsonArray=response.getJSONArray("response");
Log.i("Array Size is",Integer.toString(jsonArray.length()));
for (int i=0;i<jsonArray.length();i++)
{
JSONObject childJSONObject = jsonArray.getJSONObject(i);
//Set the flag bit to 1 since data is already at server
long result=dbHelper.insertIntoBloodPressureDetails(childJSONObject.getInt("systolic"), childJSONObject.getInt("diastolic"), childJSONObject.getLong("timestamp"),1 );
// Log.i("Insertion result ",Long.toString(result));
}
Calendar c = Calendar.getInstance(TimeZone.getTimeZone("GMT"));
c.set(Calendar.HOUR_OF_DAY, 0);
c.set(Calendar.MINUTE, 0);
c.set(Calendar.SECOND, 0);
c.set(Calendar.MILLISECOND, 0);
//This is midnight time in GMT
long unixTimeStamp = c.getTimeInMillis();
//Convert it in to Indian time System
long indianMidNightTime=unixTimeStamp-19800000;
//Log.i("Now Calculates Days","doing");
dbHelper.calculateDays(dbHelper.bpTableName, dbHelper.bpCOLUMN_days, dbHelper.bpCOLUMN_timestamp, indianMidNightTime);
}
}catch (JSONException js)
{
js.printStackTrace();
}
}
};
Response.ErrorListener errorListener=new Response.ErrorListener() {
@Override
public void one rrorResponse(VolleyError error) {
NetworkResponse response = error.networkResponse;
// Handle Error
if (error instanceof TimeoutError || error instanceof NoConnectionError) {
error.printStackTrace();
Toast.makeText(getApplicationContext(), " this Network Error", Toast.LENGTH_SHORT).show();
} else if (error instanceof AuthFailureError) {
//TODO
error.printStackTrace();
Toast.makeText(getApplicationContext(), "User not authorized", Toast.LENGTH_SHORT).show();
} else if (error instanceof ServerError && response != null)
{
try {
String res = new String(response.data,
HttpHeaderParser.parseCharset(response.headers, "utf-8"));
// Now you can use any deserializer to make sense of data
JSONObject obj = new JSONObject();
obj.put("New Error",res);
Log.i("New Server Error",obj.toString());
} catch (UnsupportedEncodingException e1) {
// Couldn't properly decode data to string
e1.printStackTrace();
} catch (JSONException e2) {
// returned data is not JSONObject?
e2.printStackTrace();
}
} else if (error instanceof NetworkError) {
//TODO
error.printStackTrace();
Toast.makeText(getApplicationContext(), "Network Error", Toast.LENGTH_SHORT).show();
} else if (error instanceof ParseError) {
//TODO
error.printStackTrace();
Toast.makeText(getApplicationContext(), "Error consuming request", Toast.LENGTH_SHORT).show();
}
else error.printStackTrace();
}
};
String bp_url=Constants.url+"bp";
JsonObjectHeader customRequest=new JsonObjectHeader(bp_url, null, listener, errorListener);
RequestQueue requestQueue = Volley.newRequestQueue(getApplicationContext());
requestQueue.add(customRequest);
}
private void dataCollected() {
JSONArray jsonArray=new JSONArray();
ArrayList<Graph> arrayList=dbHelper.fetchDataFromBp();
for (int i=0;i<arrayList.size();i++)
{
Graph graph=new Graph();
graph=arrayList.get(i);
try {
JSONObject jsonObject=new JSONObject();
jsonObject.put("systolic",graph.getHeight());
jsonObject.put("diastolic",graph.getWeight());
jsonObject.put("timestamp",graph.getTime());
jsonArray.put(jsonObject);
}catch (JSONException js)
{
js.printStackTrace();
}
}
finalData=new JSONObject();
try {
finalData.put("bp",jsonArray);
}catch (JSONException js)
{
js.printStackTrace();
}
sendDatatoServer();
}
private void sendDatatoServer()
{
Response.Listener listener=new Response.Listener<JSONObject>()
{
@Override
public void onResponse(JSONObject response) {
try {
// Parsing json object response
// response will be a json object
//Toast.makeText(getApplicationContext(),response.toString(),Toast.LENGTH_LONG).show();
Boolean responseStatusCondition = response.getBoolean("success");
Log.i("Response BP",responseStatusCondition.toString());
if (responseStatusCondition)
dbHelper.setTheFlagBpTable();
else
Log.i("Something Went Wrong"," On Server");
}
catch (JSONException k)
{
Log.i("On Response",k.getMessage());
k.printStackTrace();
}
}
};
Response.ErrorListener errorListener=new Response.ErrorListener() {
@Override
public void one rrorResponse(VolleyError error) {
// Handle Error
if (error instanceof TimeoutError || error instanceof NoConnectionError) {
error.printStackTrace();
Toast.makeText(getApplicationContext(), " this Network Error", Toast.LENGTH_SHORT).show();
} else if (error instanceof AuthFailureError) {
//TODO
error.printStackTrace();
Toast.makeText(getApplicationContext(), "User not authorized", Toast.LENGTH_SHORT).show();
} else if (error instanceof ServerError) {
//TODO
error.printStackTrace();
Toast.makeText(getApplicationContext(), "Server error", Toast.LENGTH_SHORT).show();
} else if (error instanceof NetworkError) {
//TODO
error.printStackTrace();
Toast.makeText(getApplicationContext(), "Network Error", Toast.LENGTH_SHORT).show();
} else if (error instanceof ParseError) {
//TODO
error.printStackTrace();
Toast.makeText(getApplicationContext(), "Error consuming request", Toast.LENGTH_SHORT).show();
}
else error.printStackTrace();
}
};
Log.i("Bp Final Data",finalData.toString());
JsonObjectHeader customRequest=new JsonObjectHeader(Request.Method.PUT, Constants.url+"bp", finalData, listener, errorListener);
RequestQueue requestQueue = Volley.newRequestQueue(getApplicationContext());
requestQueue.add(customRequest);
}
}
调用intentservice的代码:
Log.i("Fetch BP Data ", SendBpRecordServer.TAG);
resultReceiverBP=new MyResultReceiver(new Handler());
resultReceiverBP.setReceiver(this);
Log.i("Bp resultreceiver ",resultReceiverBP.toString());
Intent intent2=new Intent(this,SendBpRecordServer.class);
intent2.putExtra("nameTag","fetch");
intent2.putExtra("receiverTagBP",resultReceiverBP);
startService(intent2);
并在完成任务时向我发送代码
在onReceiveResult ..中,结果代码通过调用的intentservice发送,并且当计数达到5时,启动mainactivity(尽管此技巧不起作用,即在未完成分配给intentservice的任务的情况下启动mainactivity).
@Override
public void onReceiveResult(int resultCode, Bundle resultData) {
// TODO Auto-generated method stub
Log.d("Diabetes","received result from Service= "+resultData.getString("ServiceTag"));
// Log.d("BMI ","received result from Service= "+resultData.getString("ServiceTag"));
/* if (progressDialog.isShowing()) {
progressDialog.dismiss();
}*/
Log.i("Get Values ",Integer.toString(Constants.getValues));
if (resultCode==0 && resultData.getBoolean("Process_Complete"))
Constants.getValues++;
if (resultCode==1 && resultData.getBoolean("Process_Complete_bmi"))
Constants.getValues++;
if (resultCode==2 && resultData.getBoolean("Process_Complete_bp"))
Constants.getValues++;
if (resultCode==3 && resultData.getBoolean("Process_Complete_med_stats"))
Constants.getValues++;
if (resultCode==4 && resultData.getBoolean("Process_Complete_one"))
Constants.getValues++;
if (Constants.getValues==5)
{
Constants.getValues=0;
if (progressDialog.isShowing()) {
progressDialog.dismiss();
}
startActivity(new Intent(this,MainActivity.class));
finish();
}
}
解决方法:
您是否绝对确定是UI冻结的根本原因是IntentService?意图服务是专门设计用于在工作线程中运行的,以便从主(UI)线程中卸载处理,其主要原因之一是有助于防止UI冻结.
也许尝试在UI级别开始调试工作.特别是,什么是在启动ResultReceiver时将其提供给IntentService的,以及在该接收者实例中的onReceiveResult回调方法中做什么?
除此之外,对于您遇到冻结的活动,请检查您正在执行哪种操作.从主线程上的数据库中加载大量数据(即,不使用Loader或类似的方法将处理任务卸载到工作线程中)是导致UI冻结的常见原因,至少就目前为止我是这样.
更新
我想我已经解决了问题所在.有两个主要问题,都取决于您如何使用Volley.将请求添加到Volley队列时,该请求将异步执行.这意味着队列方法会立即返回.在您的意图服务代码中,这意味着该服务立即继续告诉ResultReceiver它已完成处理,而实际上它所完成的只是将请求排队.所有五个Intent服务都将执行此操作,这意味着MainActivity将很快输入.这是第一个问题.
第二个问题说明了您遇到的冻结问题.尽管Volley在工作线程上执行请求,但它返回对主线程上的请求的已解析响应-请参阅文档here.这意味着您正在intent服务中进行的所有响应处理(将数据放入数据库等). )实际上发生在主(UI)线程上.这解释了冻结.
您在这里可能想要做的是改为使用Volley的RequestFuture.通过允许您阻止直到请求完成,这基本上将异步请求转换为同步请求.为此,请创建适当类型的Future(在您的情况下为JSONObject),并将其设置为请求的侦听器和错误侦听器.然后,像现在一样对请求进行排队,然后在以后立即调用get方法.该方法将阻塞,直到响应完成处理为止.可以在意图服务中执行此操作,因为它在工作线程而不是UI线程上运行.
如果请求成功,您将获得返回的数据,并且可以执行Response.Listener实现中当前包含的所有逻辑.如果发生错误(即由于某种原因请求失败),将来的请求将引发异常,您可以处理该异常以采取任何适当的措施.
使用请求期货是与使用侦听器的完全不同的方法,您可能需要对代码进行一些更改才能使其正常工作,但是它应该可以解决您遇到的问题.
希望能对您有所帮助,我诚挚的歉意不提早发现此错误.
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