我正在为我的应用程序构建一个天气模块，我正在使用accuWeather API获取5天的天气预报详细信息。我在manifest.xml中添加了Internet权限。我试图获取日志以获取天气URL，当我单击URL时，它将在浏览器中打开并显示json文件。这意味着链接是正确的。但是，当我创建一个jsonobject并尝试将数据作为JSON数组获取时，它表明没有数据： 这是我的代码： MyWeatheractivity.java
public class MyWeather extends AppCompatactivity {
private final String TAG = "hello";
// TODO : If following are not used in activity then move the declaration to asynch task
private ArrayList<Weather> weatherArrayList = new ArrayList<>();
private ArrayList<String> dateArray = new ArrayList<>();
private ArrayList<String> minTempArray = new ArrayList<>();
private ArrayList<String>maxTempArray= new ArrayList<>();
private ArrayList<String> backgroundDayArray= new ArrayList<>();
private ArrayList<String>backgroundNightArray= new ArrayList<>();
ListView listView;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_my_weather);
findViews();
}
protected void findViews()
{
listView = findViewById(R.id.list_item1);
startFetchWeatherDetailsAsyncTask();
}
protected void startFetchWeatherDetailsAsyncTask()
{
URL weatherUrl= NetworkUtils.buildURLForWeather();
new FetchWeatherDetails().execute(weatherUrl);
Log.d(TAG,"oncreate:weatherURL : " + weatherUrl);
}
// TODO : Please make below class static and pass all the list in execute parameters
// TODO : Not doing it will cause the memory leak and you should not access activity objects directly.
private class FetchWeatherDetails extends AsyncTask<URL,Void,String>{
@Override
protected void onPreExecute(){
super.onPreExecute();
}
@Override
protected String doInBackground(URL... urls) {
URL weatherUrl =urls[0];
String weatherSearchResults=null;
try {
weatherSearchResults=NetworkUtils.getResponseFromHttpUrl(weatherUrl);
} catch (IOException e) {
e.printStackTrace();
}
return weatherSearchResults;
}
@Override
protected void onPostExecute(String weatherSearchResults) {
if(weatherSearchResults !=null && !weatherSearchResults.equals("")){
weatherArrayList =parseJSON(weatherSearchResults );
}
super.onPostExecute(weatherSearchResults);
}
private ArrayList<Weather> parseJSON(String weatherSearchResults) {
if(weatherArrayList!=null){
weatherArrayList.clear();
}
if(weatherSearchResults!=null){
try {
JSONObject rootObject= new JSONObject(weatherSearchResults);
**JSONArray results= rootObject.getJSONArray("Daily Forecasts");**
// TODO : pass the context in constructor and use weakreference
Toast.makeText(getapplicationContext(),"toast:"+results,Toast.LENGTH_LONG).show();
for(int i= 0;i<results.length();i++){
Weather weather= new Weather();
JSONObject resultObj = results.getJSONObject(i);
String date = resultObj.getString("date");
dateArray.add(date);
weather.setDate(date);
JSONObject temperatureObj = resultObj.getJSONObject("Temperature");
String minTemp=temperatureObj.getJSONObject("Minimum").getString("Value");
minTempArray.add(minTemp);
weather.setMinTemp(minTemp);
String maxTemp=temperatureObj.getJSONObject("Maximum").getString("Value");
maxTempArray.add(maxTemp);
weather.setMaxTemp(maxTemp);
JSONObject backDayObj= resultObj.getJSONObject("Day");
String backday=backDayObj.getJSONObject("IconPhrase").getString("");
backgroundDayArray.add(backday);
weather.setBackgroundDay(backday);
JSONObject backNightObj =resultObj.getJSONObject("Night");
String backnight =backNightObj.getJSONObject("IconPhrase").getString("");
backgroundNightArray.add(backnight);
weather.setBackgroundNight(backnight);
weatherArrayList.add(weather);
}
if(weatherArrayList !=null){
WeatherAdapter weatherAdapter = new WeatherAdapter(MyWeather.this,weatherArrayList);
listView.setadapter(weatherAdapter);
}else {
Toast.makeText(getapplicationContext(),"Data invalid",Toast.LENGTH_LONG).show();
}
return weatherArrayList;
} catch (JSONException e) {
e.printStackTrace();
}
}
return null;
}
}
}
getter设置程序的类
public class Weather
{
private String date;
private String minTemp;
private String maxTemp;
private String backgroundDay;
private String backgroundNight;
public String getDate() {
return date;
}
public void setDate(String date) {
this.date = date;
}
public String getMinTemp() {
return minTemp;
}
public void setMinTemp(String minTemp) {
this.minTemp = minTemp;
}
public String getMaxTemp() {
return maxTemp;
}
public void setMaxTemp(String maxTemp) {
this.maxTemp = maxTemp;
}
public String getBackgroundDay() {
return backgroundDay;
}
public void setBackgroundDay(String background) {
this.backgroundDay = background;
}
public String getBackgroundNight() {
return backgroundNight;
}
public void setBackgroundNight(String backgroundNight) {
this.backgroundNight = backgroundNight;
}
}
用于连接：
package com.example.a49ersense;
import android.net.Uri;
import android.util.Log;
import java.io.IOException;
import java.io.InputStream;
import java.net.HttpURLConnection;
import java.net.MalformedURLException;
import java.net.URL;
import java.util.Scanner;
public class NetworkUtils {
private final static String WeatherDB_Base_URL=
"https://dataservice.accuweather.com/forecasts/v1/daily/5day/location key which I have deleted";
private final static String API_KEY="my api key which i have deleted";
private final static String PARAM_API_KEY="apikey";
private static final String TAG="hello";
public static URL buildURLForWeather(){
Uri builturi = Uri.parse(WeatherDB_Base_URL).buildUpon()
.appendQueryParameter(PARAM_API_KEY,API_KEY)
.build();
URL url = null;
try {
url= new URL(builturi.toString());
} catch (MalformedURLException e) {
e.printStackTrace();
}
Log.d(TAG,"buildUrlForWeather:url:"+url);
return url;
}
public static String getResponseFromHttpUrl(URL url)throws IOException{
HttpURLConnection httpURLConnection =(HttpURLConnection) url.openConnection();
try {
InputStream in= httpURLConnection.getInputStream();
Scanner scanner = new Scanner(in);
scanner.useDelimiter("\\A");
boolean hasInput = scanner.hasnext();
if(hasInput){
return scanner.next();
}else {
return null;
}
}finally {
httpURLConnection.disconnect();
}
}
}
错误是：
W/System.err: org.json.JSONException: No value for Daily Forecasts