Http请求和Json解析结合实例

Http请求和Json解析结合实例—-天气预报项目

首先创建一个WeatherActivity，修改布局文件，添加控件，设置id

xml文件 activity_weather <?xml version="1.0" encoding="utf-8"?> <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" xmlns:app="http://schemas.android.com/apk/res-auto" xmlns:tools="http://schemas.android.com/tools" android:layout_width="match_parent" android:layout_height="match_parent" android:orientation="vertical" tools:context="com.example.administrator.urlapplication.WeatherActivity"> <EditText android:id="@+id/city_et" android:layout_width="match_parent" android:layout_height="100dp" android:hint="请输入城市名"/> <Button android:id="@+id/search_btn" android:layout_width="match_parent" android:layout_height="60dp" android:text="查询"/> <LinearLayout android:orientation="vertical" android:layout_width="match_parent" android:layout_height="wrap_content"> <TextView android:id="@+id/weather_tv" android:layout_width="match_parent" android:layout_height="wrap_content" android:text="天气:" android:textSize="30sp"/> <TextView android:id="@+id/temp_tv" android:layout_width="match_parent" android:layout_height="wrap_content" android:text="温度:" android:textSize="30sp"/> <TextView android:id="@+id/wind_tv" android:layout_width="match_parent" android:layout_height="wrap_content" android:text="风力：" android:textSize="30sp"/> </LinearLayout> </LinearLayout>

接着 在WeatherActivity内绑定id，设置监听，启动线程，并使用Http请求和Json解析结合

package com.example.administrator.urlapplication; import android.content.Context; import android.os.AsyncTask; import android.support.v7.app.AppCompatActivity; import android.os.Bundle; import android.view.View; import android.widget.TextView; import android.widget.Toast; import org.json.JSONArray; import org.json.JSONException; import org.json.JSONObject; import java.io.BufferedReader; import java.io.IOException; import java.io.InputStream; import java.io.InputStreamReader; import java.net.HttpURLConnection; import java.net.MalformedURLException; import java.net.URL; public class WeatherActivity extends AppCompatActivity { private TextView weatherTV; private TextView windTV; private TextView tempTV; private TextView searchBtn; private TextView cityET; //网络获取，和风天气 private String weatherAPI="https://free-api.heweather.com/s6/weather-now?key=f4df0dc926f54557b9c94b6c09451b51&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); } }); } class MyTask extends AsyncTask<String,String,String>{ @Override protected String doInBackground(String... strings) { StringBuffer stringBuffer=new StringBuffer(); try { //创建URL对象，接收api URL url=new URL(strings[0]); HttpURLConnection connection= (HttpURLConnection) url.openConnection(); InputStream inputStream=null; //判断是否联网 if (connection.getResponseCode()==200){ inputStream=connection.getInputStream();//只有网络正常且返回数据正常时，才能创建数据流； }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_SHORT).show(); }else { //JSON解析 try { //创建jsonobject对象，接收字符串 JSONObject object=new JSONObject(s); //创建jsonarray对象，接收数组 JSONArray array=object.getJSONArray("HeWeather6"); //创建jsonobject对象，接收数组第一个对象 JSONObject object1=array.getJSONObject(0); //创建jsonobject对象，接收对象 JSONObject nowObj=object1.getJSONObject("now"); //读取数据 String weather=nowObj.getString("cond_txt"); String wind=nowObj.getString("wind_dir")+nowObj.getString("wind_sc")+"级"; String temperature=nowObj.getString("tmp"); weatherTV.setText(weather); windTV.setText(wind); tempTV.setText(temperature); } catch (JSONException e) { e.printStackTrace(); } } } } private void bindID(){ cityET=findViewById(R.id.city_et); searchBtn=findViewById(R.id.search_btn); windTV=findViewById(R.id.wind_tv); tempTV=findViewById(R.id.temp_tv); weatherTV=findViewById(R.id.weather_tv); } }

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