20191011学习

1. runOnUiThread(new Runable（）{})；如果当前线程是ui线程，当前线程会立即执行，如果不会，则会将消息发送到ui线程的队列当中。不管在子线程还是主线程

new Thread(
                new Runnable() {
                    @Override
                    public void run() {

                        try { web= edt.getText().toString().trim();
                            URL url=new URL(web);
                            HttpURLConnection httpURLConnection = (HttpURLConnection) url.openConnection();
                            httpURLConnection.setRequestMethod("GET");
                            httpURLConnection.setConnectTimeout(5000);
                            Log.d("TAG", "run: 你好me");
                            int responseCode = httpURLConnection.getResponseCode();
                            if (responseCode==200){
                                InputStream inputStream = httpURLConnection.getInputStream();

                                byteArrayOutputStream = new ByteArrayOutputStream();
                                int len;
                                byte[] bytes=new byte[1024];
                                while((len=inputStream.read(bytes))!=-1){
                                    byteArrayOutputStream.write(bytes,0,len);
                                }
                              /*  Message obtain = Message.obtain();
                                obtain.obj=new String(byteArrayOutputStream.toByteArray());
                                Log.d("TAG", "run: 你好");
                                handler.sendMessage(obtain);*/
                              runOnUiThread(new Runnable() {
                                  @Override
                                  public void run() {
                                      tv.setText(new String(byteArrayOutputStream.toByteArray()));
                                      Log.d("TAG", "run: 你在哪里");
                                  }
                              });
                            }
                        } catch (MalformedURLException e) {
                            e.printStackTrace();
                        } catch (IOException e) {
                            e.printStackTrace();
                        }
                    }
                }
        ).start();
```