Android 为什么我的活动中存在NetworkOnMainThreadException?
我有一个下载文件的活动,执行该活动一段时间后,我在onPostExecute()上收到一个NetworkOnMainThreadException。此外,该文件未完全下载。我找不到哪里错了。这是我的密码:Android 为什么我的活动中存在NetworkOnMainThreadException?,android,networkonmainthread,Android,Networkonmainthread,我有一个下载文件的活动,执行该活动一段时间后,我在onPostExecute()上收到一个NetworkOnMainThreadException。此外,该文件未完全下载。我找不到哪里错了。这是我的密码: protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_activity1);
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_activity1);
RetrieveFeedTask download = new RetrieveFeedTask();
download.execute();
}
class RetrieveFeedTask extends AsyncTask<String, Void, InputStream> {
private Exception exception;
protected InputStream doInBackground(String... urls) {
try {
OkHttpClient client = new OkHttpClient();
Request request = new Request.Builder()
.url(URL)
.build();
Response response = client.newCall(request).execute();
InputStream asd = response.body().byteStream();
System.out.println(asd + " vaslisiss");
return asd;
} catch (Exception e) {
System.out.println("helloooo");
this.exception = e;;
return null;
}
}
protected void onPostExecute(InputStream feed) {
Log.e("mactibiti", "exception", exception);
// TODO: do something with the feed
if(exception == null)
System.out.println("asdasdasdasdasdasdads");
try{
File file = new File(Environment.getExternalStorageDirectory() + "/downloaded_file.xml");
FileOutputStream fileOutput = new FileOutputStream(file);
byte[] buffer = new byte[1024];
int bufferLength = 0;
while ( (bufferLength = feed.read(buffer)) > 0 ) {
fileOutput.write(buffer, 0, bufferLength);
}
//close the output stream when complete //
fileOutput.close();
feed.close();
}
catch(Exception e){
Log.e("filex", "ioexc", e);
}
}
}}
创建时受保护的void(Bundle savedInstanceState){
super.onCreate(savedInstanceState);
setContentView(R.layout.activity\u activity1);
RetrieveFeedTask下载=新建RetrieveFeedTask();
下载.execute();
}
类RetrieveFeedTask扩展了AsyncTask{
私人例外;
受保护的InputStream doInBackground(字符串…URL){
试一试{
OkHttpClient=新的OkHttpClient();
Request Request=newrequest.Builder()
.url(url)
.build();
Response=client.newCall(request.execute();
InputStream asd=response.body().ByTestStream();
System.out.println(asd+“Vasliss”);
返回asd;
}捕获(例外e){
System.out.println(“hellooooo”);
这个例外=e;;
返回null;
}
}
受保护的void onPostExecute(InputStream提要){
Log.e(“mactibiti”,“exception”,exception);
//TODO:对提要做些什么
if(异常==null)
System.out.println(“asdasdads”);
试一试{
File File=新文件(Environment.getExternalStorageDirectory()+“/downloaded_File.xml”);
FileOutputStream fileOutput=新的FileOutputStream(文件);
字节[]缓冲区=新字节[1024];
int bufferLength=0;
而((bufferLength=feed.read(buffer))>0){
fileOutput.write(buffer,0,bufferLength);
}
//完成后关闭输出流//
fileOutput.close();
feed.close();
}
捕获(例外e){
Log.e(“filex”、“ioexc”、e);
}
}
}}
feed
是您正在从Http调用读取的InputStream
将该代码移动到doInBackground()
您仍在使用网络读取数据如果我理解正确,feed在doInBackground()之后仍与internet连接?所以我必须把保存文件的代码放在doInBackGround()上,对吗?@billiout这是正确的。您在doInBackground()
方法中获得了流,但该流在onPostExecute()
@billiout()期间仍在从internet读取。是的,您必须
protected void onPostExecute(InputStream feed) {