我有一个执行网络操作的IntentService(HTTP POST),但它显示了一个NetworkOnMainThreadException。如果我是对的,IntentService将在一个单独的线程上运行。任何人都可以告诉为什么抛出这个异常?我的代码是:
public class UpdateService extends IntentService {
public static final int UPDATE_PROGRESS = 8344;
BroadcastReceiver broadcastReceiver;
public UpdateService() {
super("UpdateService");
}
@Override
protected void onHandleIntent(Intent intent) {
if (broadcastReceiver == null) {
broadcastReceiver = new BroadcastReceiver() {
@Override
public void onReceive(Context context, Intent intent) {
Bundle extras = intent.getExtras();
NetworkInfo info = (NetworkInfo) extras.getParcelable("networkInfo");
State state = info.getState();
if (state == State.CONNECTED) {
onNetworkUp();
} else {
}
}
};
final IntentFilter intentFilter = new IntentFilter();
intentFilter.addAction(ConnectivityManager.CONNECTIVITY_ACTION);
registerReceiver(broadcastReceiver, intentFilter);
}
}
@Override
public void onDestroy(){
unregisterReceiver(broadcastReceiver);
}
void onNetworkUp(){
String aDataRow = "";
try {
File myFile = new File( Environment.getExternalStorageDirectory().getPath() + "/myFile.txt");
FileReader fr = new FileReader(myFile);
BufferedReader myReader = new BufferedReader(fr);
while ((aDataRow = myReader.readLine()) != null)
updateLyne(aDataRow); //
fr.close();
} catch (Exception e) {
Log.e("onNetworkUp",e.toString());
}
void updateLyne(String aDataRow){
JSONParser jsonParser = new JSONParser();
String[] words = aDataRow.split(" ");
pid = words[1];
String rtime = aDataRow;
List<NameValuePair> params = new ArrayList<NameValuePair>();
params.add(new BasicNameValuePair(TAG_PID, pid));
params.add(new BasicNameValuePair(TAG_TIME, rtime));
JSONObject json = null;
if (words[0].equalsIgnoreCase("cancel")){
json = jsonParser.makeHttpRequest(url_cancel, "POST", params);
}
else{
Log.d("empty","file empty!!");
}
try {
int success = json.getInt("success");
if (success == 1) {
delLine(aDataRow); // delete the line
} else {
Log.d("pid="+pid+" not on board", "failed in deleting");
}
} catch (JSONException e) {
e.printStackTrace();
}
}
}
JSONParser.java在下面给出
public class JSONParser {
static InputStream is = null;
static JSONObject jObj = null;
static String json = "";
// constructor
public JSONParser() {
}
// function get json from url
public JSONObject makeHttpRequest(String url, String method,
List<NameValuePair> params) {
// Making HTTP request
try {
// check for request method
if(method == "POST"){
DefaultHttpClient httpClient = new DefaultHttpClient();
HttpPost httpPost = new HttpPost(url);
httpPost.setEntity(new UrlEncodedFormEntity(params));
HttpResponse httpResponse = httpClient.execute(httpPost);
HttpEntity httpEntity = httpResponse.getEntity();
is = httpEntity.getContent();
}
} catch (UnsupportedEncodingException e) {
e.printStackTrace();
} catch (ClientProtocolException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
try {
BufferedReader reader = new BufferedReader(new InputStreamReader(
is, "iso-8859-1"), 8);
StringBuilder sb = new StringBuilder();
String line = null;
while ((line = reader.readLine()) != null) {
sb.append(line + "\n");
}
is.close();
json = sb.toString();
} catch (Exception e) {
Log.e("Buffer Error", "Error converting result " + e.toString());
}
// try parse the string to a JSON object
try {
jObj = new JSONObject(json);
} catch (JSONException e) {
Log.e("JSON Parser", "Error parsing data " + e.toString());
}
// return JSON String
return jObj;
}
}
答案 0 :(得分:1)
问题是您没有在onHandleIntent()
中运行网络请求,而只是创建BroadcastReceiver
的实例并注册它。实际的网络请求不会在那里运行。它将在BroadcastReceiver
收到消息时运行,该消息发生在UI线程上。这里的正确方案是在其他地方创建BroadcastReceiver
,当收到消息时,启动IntentService
,在onHandleIntent()
内执行网络调用 - 然后确实会运行工人线程。希望这会有所帮助。