特别是，在android中非常新，并且不熟悉调试它。问题是每当我点击刷新按钮没有任何反应时，它必须显示真实数据，它继续显示虚假数据。 logcat说该文件不存在，在这里找不到错误。 这是我的代码
主要活动
package com.example.android.sunshine.app;
import android.annotation.TargetApi;
import android.support.v4.app.Fragment;
import android.os.Build;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ArrayAdapter;
import android.widget.ListView;
import android.widget.TextView;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.net.HttpURLConnection;
import java.net.URL;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;
public class MainActivity extends AppCompatActivity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
/** if (savedInstanceState == null){
getSupportFragmentManager().beginTransaction()
.add(R.id.container, new ForecastFragment())
.commit();
}*/
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.main, menu);
return true;
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
// Handle action bar item clicks here. The action bar will
// automatically handle clicks on the Home/Up button, so long
// as you specify a parent activity in AndroidManifest.xml.
int id = item.getItemId();
//noinspection SimplifiableIfStatement
if (id == R.id.action_settings) {
return true;
}
if (id == R.id.action_refresh){
return true;
}
return super.onOptionsItemSelected(item);
}
}
forecastFragment
package com.example.android.sunshine.app;
import android.net.*;
import android.os.*;
import android.support.v4.app.*;
import android.text.format.*;
import android.util.*;
import android.view.*;
import android.widget.*;
import org.json.*;
import java.io.*;
import java.net.*;
import java.text.*;
import java.util.*;
/**
* Created by Nabahat on 7/8/2015.
*/
public class ForecastFragment extends Fragment {
private ArrayAdapter<String> mForecastAdapter;
public ForecastFragment(){}
@Override
public void onCreate(Bundle savedInstanceState){
super.onCreate(savedInstanceState);
setHasOptionsMenu(true);
}
@Override
public void onCreateOptionsMenu(Menu menu, MenuInflater inflater){
inflater.inflate(R.menu.forecastfragment, menu);
}
@Override
public boolean onOptionsItemSelected(MenuItem item){
int id = item.getItemId();
if (id==R.id.action_refresh){
FetchWeatherTask weatherTask = new FetchWeatherTask();
weatherTask.execute("94043");
return true;
}
return super.onOptionsItemSelected(item);
}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.fragment_main, container, false);
String[] forecastArray = {
"Today - Sunny - 88/63",
"Tomorrow - Foggy - 70/40",
"Weds - Cloudy - 72/63",
"Thurs - Asteroids - 75/65",
"Fri - Heavy Rain - 65/56",
"Sat - HELP TRAPPED IN WEATHERSTATION - 60/51",
"Sun - Sunny - 80/68"
};
List<String> weekForecast = new ArrayList<String>(
Arrays.asList(forecastArray));
ArrayAdapter<String> mForecastAdapter = new ArrayAdapter<String>(
getActivity(),
R.layout.list_item_forecast,
R.id.list_item_forecast_textview,
weekForecast);
ListView listView = (ListView) rootView.findViewById(R.id.listview_forecast);
listView.setAdapter(mForecastAdapter);
return rootView;
}
public class FetchWeatherTask extends AsyncTask<String, Void, String[]> {
private final String LOG_TAG = FetchWeatherTask.class.getSimpleName();
/* The date/time conversion code is going to be moved outside the asynctask later,
* so for convenience we're breaking it out into its own method now.
*/
private String getReadableDateString(long time){
// Because the API returns a unix timestamp (measured in seconds),
// it must be converted to milliseconds in order to be converted to valid date.
SimpleDateFormat shortenedDateFormat = new SimpleDateFormat("EEE MMM dd");
return shortenedDateFormat.format(time);
}
/**
* Prepare the weather high/lows for presentation.
*/
private String formatHighLows(double high, double low) {
// For presentation, assume the user doesn't care about tenths of a degree.
long roundedHigh = Math.round(high);
long roundedLow = Math.round(low);
String highLowStr = roundedHigh + "/" + roundedLow;
return highLowStr;
}
/**
* Take the String representing the complete forecast in JSON Format and
* pull out the data we need to construct the Strings needed for the wireframes.
*
* Fortunately parsing is easy: constructor takes the JSON string and converts it
* into an Object hierarchy for us.
*/
private String[] getWeatherDataFromJson(String forecastJsonStr, int numDays)
throws JSONException {
// These are the names of the JSON objects that need to be extracted.
final String OWM_LIST = "list";
final String OWM_WEATHER = "weather";
final String OWM_TEMPERATURE = "temp";
final String OWM_MAX = "max";
final String OWM_MIN = "min";
final String OWM_DESCRIPTION = "main";
JSONObject forecastJson = new JSONObject(forecastJsonStr);
JSONArray weatherArray = forecastJson.getJSONArray(OWM_LIST);
// OWM returns daily forecasts based upon the local time of the city that is being
// asked for, which means that we need to know the GMT offset to translate this data
// properly.
// Since this data is also sent in-order and the first day is always the
// current day, we're going to take advantage of that to get a nice
// normalized UTC date for all of our weather.
Time dayTime = new Time();
dayTime.setToNow();
// we start at the day returned by local time. Otherwise this is a mess.
int julianStartDay = Time.getJulianDay(System.currentTimeMillis(), dayTime.gmtoff);
// now we work exclusively in UTC
dayTime = new Time();
String[] resultStrs = new String[numDays];
for(int i = 0; i < weatherArray.length(); i++) {
// For now, using the format "Day, description, hi/low"
String day;
String description;
String highAndLow;
// Get the JSON object representing the day
JSONObject dayForecast = weatherArray.getJSONObject(i);
// The date/time is returned as a long. We need to convert that
// into something human-readable, since most people won't read "1400356800" as
// "this saturday".
long dateTime;
// Cheating to convert this to UTC time, which is what we want anyhow
dateTime = dayTime.setJulianDay(julianStartDay+i);
day = getReadableDateString(dateTime);
// description is in a child array called "weather", which is 1 element long.
JSONObject weatherObject = dayForecast.getJSONArray(OWM_WEATHER).getJSONObject(0);
description = weatherObject.getString(OWM_DESCRIPTION);
// Temperatures are in a child object called "temp". Try not to name variables
// "temp" when working with temperature. It confuses everybody.
JSONObject temperatureObject = dayForecast.getJSONObject(OWM_TEMPERATURE);
double high = temperatureObject.getDouble(OWM_MAX);
double low = temperatureObject.getDouble(OWM_MIN);
highAndLow = formatHighLows(high, low);
resultStrs[i] = day + " - " + description + " - " + highAndLow;
}
for (String s : resultStrs){
Log.v(LOG_TAG, "Forecast entry: " + s);
}
return resultStrs;
}
@Override
protected String[] doInBackground(String... params){
if(params.length == 0){
return null;
}
HttpURLConnection urlConnection = null;
BufferedReader reader = null;
String forecastJsonStr = null;
String format = "jason";
String units = "metric";
int numDays = 7;
try {
final String FORECAST_BASE_URL =
"http://api.openweathermap.org/data/2.5/forecast/daily?";
final String QUERY_PARAM = "q";
final String FORMAT_PARAM = "mode";
final String UNITS_PARAM = "units";
final String DAYS_PARAM = "cnt";
Uri builtUri = Uri.parse(FORECAST_BASE_URL).buildUpon()
.appendQueryParameter(QUERY_PARAM, params[0])
.appendQueryParameter(FORMAT_PARAM, format)
.appendQueryParameter(UNITS_PARAM, units)
.appendQueryParameter(DAYS_PARAM, Integer.toString(numDays))
.build();
URL url = new URL(builtUri.toString());
Log.v(LOG_TAG, "Built URI " + builtUri.toString());
urlConnection = (HttpURLConnection) url.openConnection();
urlConnection.setRequestMethod("GET");
urlConnection.setRequestProperty("API_KEY", "c84aeef73dfe54e9ec696154cfb89a5a");
urlConnection.setDoInput(true);
urlConnection.setDoOutput(true);
urlConnection.connect();
InputStream inputStream = urlConnection.getInputStream();
StringBuffer buffer = new StringBuffer();
if (inputStream == null) {
return null;
}
reader = new BufferedReader(new InputStreamReader(inputStream));
String line;
while ((line = reader.readLine()) != null) {
buffer.append(line + "\n");
}
if (buffer.length() == 0) {
return null;
}
forecastJsonStr = buffer.toString();
Log.v(LOG_TAG, "Forecast JSON String: "+ forecastJsonStr);
} catch (IOException e) {
Log.e(LOG_TAG, "Error ", e);
return null;
} finally{
if (urlConnection != null) {
urlConnection.disconnect();
}
if (reader != null) {
try {
reader.close();
} catch (final IOException e) {
Log.e(LOG_TAG, "Error closing stream", e);
}
}
}
try{
return getWeatherDataFromJson(forecastJsonStr, numDays);
} catch (JSONException e){
Log.e(LOG_TAG, e.getMessage(), e);
e.printStackTrace();
}
return null;
}
@Override
protected void onPostExecute(String[] result){
if (result != null){
mForecastAdapter.clear();
for (String dayForecastStr : result){
mForecastAdapter.add(dayForecastStr);
}
}
}
}
}
logcat的
10670-10670/com.example.android.sunshine.app W/art﹕ Before Android 4.1, method int android.support.v7.internal.widget.ListViewCompat.lookForSelectablePosition(int, boolean) would have incorrectly overridden the package-private method in android.widget.ListView
07-09 06:12:19.182 10670-10692/com.example.android.sunshine.app W/EGL_emulation﹕ eglSurfaceAttrib not implemented
07-09 06:12:19.182 10670-10692/com.example.android.sunshine.app W/OpenGLRenderer﹕ Failed to set EGL_SWAP_BEHAVIOR on surface 0xa5403460, error=EGL_SUCCESS
07-09 06:12:19.627 10670-10677/com.example.android.sunshine.app W/art﹕ Suspending all threads took: 21.107ms
07-09 06:12:21.091 10670-10764/com.example.android.sunshine.app V/FetchWeatherTask﹕ Built URI http://api.openweathermap.org/data/2.5/forecast/daily?q=94043&mode=jason&units=metric&cnt=7
07-09 06:12:21.163 10670-10670/com.example.android.sunshine.app W/InputEventReceiver﹕ Attempted to finish an input event but the input event receiver has already been disposed.
07-09 06:12:22.087 10670-10764/com.example.android.sunshine.app E/FetchWeatherTask﹕ Error
java.io.FileNotFoundException: http://api.openweathermap.org/data/2.5/forecast/daily?q=94043&mode=jason&units=metric&cnt=7
at com.android.okhttp.internal.http.HttpURLConnectionImpl.getInputStream(HttpURLConnectionImpl.java:206)
at com.example.android.sunshine.app.ForecastFragment$FetchWeatherTask.doInBackground(ForecastFragment.java:217)
at com.example.android.sunshine.app.ForecastFragment$FetchWeatherTask.doInBackground(ForecastFragment.java:75)
at android.os.AsyncTask$2.call(AsyncTask.java:292)
at java.util.concurrent.FutureTask.run(FutureTask.java:237)
at android.os.AsyncTask$SerialExecutor$1.run(AsyncTask.java:231)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1112)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:587)
at java.lang.Thread.run(Thread.java:818)
07-09 06:12:31.513 10670-10677/com.example.android.sunshine.app W/art﹕ Suspending all threads took: 8.898ms
答案 0 :(得分：0)
根据您的日志，通过检查响应，添加这两个行代码
，解决了同样的问题urlConnection.setRequestProperty("User-Agent","Mozilla/5.0 ( compatible ) ");
urlConnection.setRequestProperty("Accept","*/*");
并设置
urlConnection.setDoOutput(false);
您可以参考以下两个答案：
HttpURLConnection java.io.FileNotFoundException
FileNotFoundException while getting the InputStream object from HttpURLConnection
答案 1 :(得分：0)
您需要将Open Weather API密钥附加到网址。