这段代码在java中工作得很好,但在android中却不行
我在主线程的这段代码在java中工作得很好,但在android中却不行,android,urlconnection,Android,Urlconnection,我在主线程的onCreate方法中调用它 StringBuilder content = new StringBuilder(); try { URL url = new URL("http://alvinalexander.com/blog/post/java/java-how-read-from-url-string-text"); URLConnection urlConnection = u
onCreate
方法中调用它
StringBuilder content = new StringBuilder();
try
{
URL url = new URL("http://alvinalexander.com/blog/post/java/java-how-read-from-url-string-text");
URLConnection urlConnection = url.openConnection();
BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(urlConnection.getInputStream()));
String line;
while ((line = bufferedReader.readLine()) != null)
{
content.append(line + "\n");
}
bufferedReader.close();
}
catch(Exception e)
{
e.printStackTrace();
}
Log.d("rwj", content.toString());
我在
Asynctask
中尝试了很多代码,效果很好,我想网络操作不能在主UI线程中完成
class RetrieveFeedTask扩展了AsyncTask
{
私人例外;
StringBuilder内容=新建StringBuilder();
受保护的字符串doInBackground(字符串…URL){
尝试
{
//创建url对象
URL=新URL(“http://samples.openweathermap.org/data/2.5/weather?q=London,英国&appid=b1b15e88fa797225412429c1c50c122a1”);
//创建urlconnection对象
URLConnection URLConnection=url.openConnection();
//将urlconnection包装在bufferedreader中
BufferedReader BufferedReader=新的BufferedReader(新的InputStreamReader(urlConnection.getInputStream());
弦线;
//通过bufferedreader从urlconnection读取
而((line=bufferedReader.readLine())!=null)
{
content.append(第+行“\n”);
}
bufferedReader.close();
}
捕获(例外e)
{
Log.d(“myerr”,例如toString());
}
返回content.toString();
}
受保护的void onPostExecute(字符串结果){
Log.d(“myresut”,result.toString());
}
}
您是否在清单中添加了internet权限?可能与Post错误日志重复,如上所述检查清单。Rameez Jawaid,在onCreate方法中执行此类工作的想法是错误的。我会使用asynctask(或类似的东西)。问题是,网络操作无法在主ui线程中完成,因为我已经在Google上搜索过了。是的,它以异步任务的方式工作得很好。
class RetrieveFeedTask extends AsyncTask<String, Void, String>
{
private Exception exception;
StringBuilder content = new StringBuilder();
protected String doInBackground(String... urls) {
try
{
// create a url object
URL url = new URL("http://samples.openweathermap.org/data/2.5/weather?q=London,uk&appid=b1b15e88fa797225412429c1c50c122a1");
// create a urlconnection object
URLConnection urlConnection = url.openConnection();
// wrap the urlconnection in a bufferedreader
BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(urlConnection.getInputStream()));
String line;
// read from the urlconnection via the bufferedreader
while ((line = bufferedReader.readLine()) != null)
{
content.append(line + "\n");
}
bufferedReader.close();
}
catch(Exception e)
{
Log.d("myerr", e.toString());
}
return content.toString();
}
protected void onPostExecute(String result) {
Log.d("myresut", result.toString());
}
}