xml代码如下：
<EditText android:gravity="center" android:id="@+id/city_et" android:layout_width="match_parent" android:layout_height="wrap_content" android:hint="请输入城市名" /> <Button android:id="@+id/search_btn" android:layout_width="150dp" android:layout_gravity="center" android:layout_height="50dp" android:textSize="20sp" android:text="查询" /> <TextView android:layout_width="match_parent" android:layout_height="100dp" /> <LinearLayout android:layout_width="match_parent" android:layout_height="match_parent" android:orientation="vertical"> <RelativeLayout android:layout_width="match_parent" android:layout_height="50dp"> <TextView android:id="@+id/tianqi_tv" android:layout_width="100dp" android:layout_height="50dp" android:gravity="center" android:textSize="25sp" android:text="天气：" /> <TextView android:id="@+id/weather_tv" android:layout_width="wrap_content" android:layout_height="50dp" android:textSize="25sp" android:gravity="center" android:layout_toRightOf="@+id/tianqi_tv" /> </RelativeLayout> <RelativeLayout android:layout_width="match_parent" android:layout_height="50dp"> <TextView android:id="@+id/fengli_tv" android:layout_width="100dp" android:layout_height="50dp" android:gravity="center" android:textSize="25sp" android:text="风力：" /> <TextView android:id="@+id/wind_tv" android:layout_width="wrap_content" android:textSize="25sp" android:layout_height="50dp" android:gravity="center" android:layout_toRightOf="@+id/fengli_tv" /> </RelativeLayout> <RelativeLayout android:layout_width="match_parent" android:layout_height="50dp"> <TextView android:id="@+id/wendu_tv" android:layout_width="100dp" android:layout_height="50dp" android:gravity="center" android:textSize="25sp" android:text="温度：" /> <TextView android:id="@+id/temp_tv" android:layout_width="wrap_content" android:layout_height="50dp" android:textSize="25sp" android:gravity="center" android:layout_toRightOf="@+id/wendu_tv" /> </RelativeLayout> </LinearLayout>layout代码如下：
public class WeatherActivity extends AppCompatActivity { private TextView weatherTV; private TextView windTV; private TextView tempTV; private Button searchBTN; private EditText cityET; private String weatherAPI="https://free-api.heweather.com/s6/weather/now?key=8392825b30894374a86421ad2dba3def&location="; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_weather); bindID(); searchBTN.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View view) { String city=cityET.getText().toString(); new MyTask().execute(weatherAPI+city); } }); } private void bindID() { cityET=findViewById(R.id.city_et); searchBTN=findViewById(R.id.search_btn); weatherTV=findViewById(R.id.weather_tv); windTV=findViewById(R.id.wind_tv); tempTV=findViewById(R.id.temp_tv); } class MyTask extends AsyncTask<String,String,String>{ @Override protected String doInBackground(String... strings) { StringBuffer stringBuffer=new StringBuffer(); try{ URL url=new URL(strings[0]); HttpURLConnection connection=(HttpURLConnection)url.openConnection(); InputStream inputStream=null; if(connection.getResponseCode()==200){ inputStream=connection.getInputStream();//只有网络正常返回数据正常是，我们才创建输入流 }else { return "network_failed"; } InputStreamReader reader=new InputStreamReader(inputStream); BufferedReader bufferedReader=new BufferedReader(reader); String temp=""; while ((temp=bufferedReader.readLine())!=null) { stringBuffer.append(temp); } bufferedReader.close(); reader.close(); inputStream.close(); } catch (MalformedURLException e) { e.printStackTrace(); } catch (IOException e) { e.printStackTrace(); } return stringBuffer.toString(); } @Override protected void onPostExecute(String s) { super.onPostExecute(s); if (s.equals("network_failed")){ Toast.makeText(WeatherActivity.this,"网络连接失败",Toast.LENGTH_LONG).show(); }else { //JSON解析 try{ JSONObject object=new JSONObject(s); JSONArray array=object.getJSONArray("HeWeather6"); JSONObject object1=array.getJSONObject(0); JSONObject nowObj=object1.getJSONObject("now"); String weather=nowObj.getString("cond_txt"); String wind=nowObj.getString("wind_dir")+nowObj.getString("wind_sc")+"级"; String temperature=nowObj.getString("tmp")+"度"; weatherTV.setText(weather); windTV.setText(wind); tempTV.setText(temperature); } catch (JSONException e) { e.printStackTrace(); } } } } } 首先绑定ID，声明一个全局的API定义一个MyTask继承AsyncTask,在DoInBackground方法中实现联网获取数据的耗时操作（可以通过一个if else 判断网络连接是否有用）。在网络连接正常的情况下，接着创建输入流。
在PostExcute方法中利用JSON获取API接口中的数据（注意分清Object还是Array)，同样可以判断一下网络连接是否正常。
