调出每小时天气预报数据时出错：java.lang.IllegalStateException：无法执行 android:onClick 的方法
Error bringing up hourly weather forecast datar: java.lang.IllegalStateException: Could not execute method for android:onClick
我的 Android 工作室项目存在运行时问题。这是一个天气应用程序，试图从 API 中调出每小时的预报数据。提出主要 activity 的意图不断提出 IllegalStateException。看起来代码本身没有错误
这是主要的 activity 文件。
package com.teamtreehouse.stormy.ui;
import android.content.Context;
import android.content.Intent;
import android.databinding.DataBindingUtil;
import android.graphics.drawable.Drawable;
import android.net.ConnectivityManager;
import android.net.NetworkInfo;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.text.method.LinkMovementMethod;
import android.util.Log;
import android.view.View;
import android.widget.ImageView;
import android.widget.TextView;
import android.widget.Toast;
import com.teamtreehouse.stormy.R;
import com.teamtreehouse.stormy.Weather.Current;
import com.teamtreehouse.stormy.Weather.Forecast;
import com.teamtreehouse.stormy.Weather.Hour;
import com.teamtreehouse.stormy.databinding.ActivityMainBinding;
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;
import java.io.IOException;
import java.io.Serializable;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;
import okhttp3.Call;
import okhttp3.Callback;
import okhttp3.OkHttpClient;
import okhttp3.Request;
import okhttp3.Response;
public class MainActivity extends AppCompatActivity {
public static final String TAG = MainActivity.class.getSimpleName();
private Forecast forecast;
private ImageView iconImageView;
double latitude = 37.8267;
double longitude = -122.4233;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
getForecast(latitude, longitude);
Log.d(TAG, "Main UI code is running, hooray!");
}
private void getForecast(double latitude, double longitude) {
final ActivityMainBinding binding = DataBindingUtil
.setContentView(MainActivity.this, R.layout.activity_main);
iconImageView = findViewById(R.id.iconImageView);
// Setup Dark Sky Link
TextView darkSky = findViewById(R.id.darkSkyAttribution);
darkSky.setMovementMethod(LinkMovementMethod.getInstance());
String apiKey = "57eaf3aa961968bf65b0619680588073";
String forecastURL = "https://api.darksky.net/forecast/" + apiKey +
"/" + latitude + "," + longitude;
if (isNetworkAvailable()) {
OkHttpClient client = new OkHttpClient();
Request request = new Request.Builder()
.url(forecastURL)
.build();
Call call = client.newCall(request);
call.enqueue(new Callback() {
@Override
public void onFailure(Call call, IOException e) {
}
@Override
public void onResponse(Call call, Response response) throws IOException {
try {
String jsonData = response.body().string();
Log.v(TAG, jsonData);
if (response.isSuccessful()) {
forecast = parseForecastData(jsonData);
Current current = forecast.getCurrent();
final Current displayWeather = new Current(
current.getLocationLabel(),
current.getIcon(),
current.getTime(),
current.getTemperature(),
current.getHumidity(),
current.getPrecipChance(),
current.getSummary(),
current.getTimeZone()
);
binding.setWeather(displayWeather);
runOnUiThread(new Runnable() {
@Override
public void run() {
Drawable drawable = getResources().getDrawable(displayWeather.getIconId());
iconImageView.setImageDrawable(drawable);
}
});
} else {
alertUserAboutError();
}
} catch (IOException e) {
Log.e(TAG, "IO Exception caught: ", e);
} catch (JSONException e) {
Log.e(TAG, "JSON Exception caught: ", e);
}
}
});
}
else {
Toast.makeText(this, R.string.network_unavailable_message,
Toast.LENGTH_LONG).show();
}
}
private Forecast parseForecastData(String jsonData) throws JSONException {
Forecast forecast = new Forecast();
forecast.setCurrent(getCurrentDetails(jsonData));
return forecast;
}
private Hour[] getHourlyForecast(String jsonData) throws JSONException {
JSONObject forecast = new JSONObject(jsonData);
String timezone = forecast.getString("timezone");
//get an array of JSON objects
JSONObject hourly = forecast.getJSONObject("hourly");
JSONArray data = hourly.getJSONArray("data");
Hour[] hours = new Hour[data.length()];
for (int i=0; i<data.length(); i++){
JSONObject jsonHour = data.getJSONObject(i);
Hour hour = new Hour();
hour.setSummary(jsonHour.getString("summary"));
hour.setIcon(jsonHour.getString("icon"));
hour.setTemperature(jsonHour.getDouble("temperature"));
hour.setTime(jsonHour.getLong("time"));
hour.setTimeZone(timezone);
hours[i] = hour;
}
return hours;
}
private Current getCurrentDetails(String jsonData) throws JSONException {
JSONObject forecast = new JSONObject(jsonData);
String timezone = forecast.getString("timezone");
Log.i(TAG, "From JSON: " + timezone);
JSONObject currently = forecast.getJSONObject("currently");
Current current = new Current();
// Parse weather data from currently object
current.setHumidity(currently.getDouble("humidity"));
current.setTime(currently.getLong("time"));
current.setIcon(currently.getString("icon"));
current.setLocationLabel("Alcatraz Island, CA");
current.setPrecipChance(currently.getDouble("precipProbability"));
current.setSummary(currently.getString("summary"));
current.setTemperature(currently.getDouble("temperature"));
current.setTimeZone(timezone);
Log.d(TAG, current.getFormattedTime());
return current;
}
private boolean isNetworkAvailable() {
ConnectivityManager manager = (ConnectivityManager) getSystemService(Context.CONNECTIVITY_SERVICE);
NetworkInfo networkInfo = manager.getActiveNetworkInfo();
boolean isAvailable = false;
if (networkInfo != null && networkInfo.isConnected()) {
isAvailable = true;
}
return isAvailable;
}
private void alertUserAboutError() {
AlertDialogFragment dialog = new AlertDialogFragment();
dialog.show(getFragmentManager(), "error_dialog");
}
public void refreshOnClick(View view) {
getForecast(latitude, longitude);
Toast.makeText(this, "Refreshing data", Toast.LENGTH_LONG).show();
}
public void hourlyOnClick(View view) {
List<Hour> hours = Arrays.asList(forecast.getHourlyForecast());
Intent intent = new Intent(this, HourlyForecastActivity.class);
intent.putExtra("HourlyList", (Serializable) hours);
startActivity(intent);
}
}
这是我的堆栈跟踪
07-19 09:53:53.662 12590-12590/uk.co.jonniegrieve.stormy E/AndroidRuntime: FATAL EXCEPTION: main
Process: uk.co.jonniegrieve.stormy, PID: 12590
java.lang.IllegalStateException: Could not execute method for android:onClick
at android.support.v7.app.AppCompatViewInflater$DeclaredOnClickListener.onClick(AppCompatViewInflater.java:389)
at android.view.View.performClick(View.java:5198)
at android.view.View$PerformClick.run(View.java:21147)
at android.os.Handler.handleCallback(Handler.java:739)
at android.os.Handler.dispatchMessage(Handler.java:95)
at android.os.Looper.loop(Looper.java:148)
at android.app.ActivityThread.main(ActivityThread.java:5417)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:726)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:616)
Caused by: java.lang.reflect.InvocationTargetException
at java.lang.reflect.Method.invoke(Native Method)
at android.support.v7.app.AppCompatViewInflater$DeclaredOnClickListener.onClick(AppCompatViewInflater.java:384)
at android.view.View.performClick(View.java:5198)
at android.view.View$PerformClick.run(View.java:21147)
at android.os.Handler.handleCallback(Handler.java:739)
at android.os.Handler.dispatchMessage(Handler.java:95)
at android.os.Looper.loop(Looper.java:148)
at android.app.ActivityThread.main(ActivityThread.java:5417)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:726)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:616)
Caused by: java.lang.NullPointerException: storage == null
at java.util.Arrays$ArrayList.<init>(Arrays.java:38)
at java.util.Arrays.asList(Arrays.java:155)
at com.teamtreehouse.stormy.ui.MainActivity.hourlyOnClick(MainActivity.java:222)
at java.lang.reflect.Method.invoke(Native Method)
at android.support.v7.app.AppCompatViewInflater$DeclaredOnClickListener.onClick(AppCompatViewInflater.java:384)
at android.view.View.performClick(View.java:5198)
at android.view.View$PerformClick.run(View.java:21147)
at android.os.Handler.handleCallback(Handler.java:739)
at android.os.Handler.dispatchMessage(Handler.java:95)
at android.os.Looper.loop(Looper.java:148)
at android.app.ActivityThread.main(ActivityThread.java:5417)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:726)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:616)
07-19 09:53:53.682 1228-1228/? E/EGL_emulation: tid 1228: eglCreateSyncKHR(1881): error 0x3004 (EGL_BAD_ATTRIBUTE
)
看起来 hourlyOnClick returns 中的方法 forecast.getHourlyForecast() 为 null 而不是数组。
我的 Android 工作室项目存在运行时问题。这是一个天气应用程序，试图从 API 中调出每小时的预报数据。提出主要 activity 的意图不断提出 IllegalStateException。看起来代码本身没有错误
这是主要的 activity 文件。
package com.teamtreehouse.stormy.ui;
import android.content.Context;
import android.content.Intent;
import android.databinding.DataBindingUtil;
import android.graphics.drawable.Drawable;
import android.net.ConnectivityManager;
import android.net.NetworkInfo;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.text.method.LinkMovementMethod;
import android.util.Log;
import android.view.View;
import android.widget.ImageView;
import android.widget.TextView;
import android.widget.Toast;
import com.teamtreehouse.stormy.R;
import com.teamtreehouse.stormy.Weather.Current;
import com.teamtreehouse.stormy.Weather.Forecast;
import com.teamtreehouse.stormy.Weather.Hour;
import com.teamtreehouse.stormy.databinding.ActivityMainBinding;
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;
import java.io.IOException;
import java.io.Serializable;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;
import okhttp3.Call;
import okhttp3.Callback;
import okhttp3.OkHttpClient;
import okhttp3.Request;
import okhttp3.Response;
public class MainActivity extends AppCompatActivity {
public static final String TAG = MainActivity.class.getSimpleName();
private Forecast forecast;
private ImageView iconImageView;
double latitude = 37.8267;
double longitude = -122.4233;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
getForecast(latitude, longitude);
Log.d(TAG, "Main UI code is running, hooray!");
}
private void getForecast(double latitude, double longitude) {
final ActivityMainBinding binding = DataBindingUtil
.setContentView(MainActivity.this, R.layout.activity_main);
iconImageView = findViewById(R.id.iconImageView);
// Setup Dark Sky Link
TextView darkSky = findViewById(R.id.darkSkyAttribution);
darkSky.setMovementMethod(LinkMovementMethod.getInstance());
String apiKey = "57eaf3aa961968bf65b0619680588073";
String forecastURL = "https://api.darksky.net/forecast/" + apiKey +
"/" + latitude + "," + longitude;
if (isNetworkAvailable()) {
OkHttpClient client = new OkHttpClient();
Request request = new Request.Builder()
.url(forecastURL)
.build();
Call call = client.newCall(request);
call.enqueue(new Callback() {
@Override
public void onFailure(Call call, IOException e) {
}
@Override
public void onResponse(Call call, Response response) throws IOException {
try {
String jsonData = response.body().string();
Log.v(TAG, jsonData);
if (response.isSuccessful()) {
forecast = parseForecastData(jsonData);
Current current = forecast.getCurrent();
final Current displayWeather = new Current(
current.getLocationLabel(),
current.getIcon(),
current.getTime(),
current.getTemperature(),
current.getHumidity(),
current.getPrecipChance(),
current.getSummary(),
current.getTimeZone()
);
binding.setWeather(displayWeather);
runOnUiThread(new Runnable() {
@Override
public void run() {
Drawable drawable = getResources().getDrawable(displayWeather.getIconId());
iconImageView.setImageDrawable(drawable);
}
});
} else {
alertUserAboutError();
}
} catch (IOException e) {
Log.e(TAG, "IO Exception caught: ", e);
} catch (JSONException e) {
Log.e(TAG, "JSON Exception caught: ", e);
}
}
});
}
else {
Toast.makeText(this, R.string.network_unavailable_message,
Toast.LENGTH_LONG).show();
}
}
private Forecast parseForecastData(String jsonData) throws JSONException {
Forecast forecast = new Forecast();
forecast.setCurrent(getCurrentDetails(jsonData));
return forecast;
}
private Hour[] getHourlyForecast(String jsonData) throws JSONException {
JSONObject forecast = new JSONObject(jsonData);
String timezone = forecast.getString("timezone");
//get an array of JSON objects
JSONObject hourly = forecast.getJSONObject("hourly");
JSONArray data = hourly.getJSONArray("data");
Hour[] hours = new Hour[data.length()];
for (int i=0; i<data.length(); i++){
JSONObject jsonHour = data.getJSONObject(i);
Hour hour = new Hour();
hour.setSummary(jsonHour.getString("summary"));
hour.setIcon(jsonHour.getString("icon"));
hour.setTemperature(jsonHour.getDouble("temperature"));
hour.setTime(jsonHour.getLong("time"));
hour.setTimeZone(timezone);
hours[i] = hour;
}
return hours;
}
private Current getCurrentDetails(String jsonData) throws JSONException {
JSONObject forecast = new JSONObject(jsonData);
String timezone = forecast.getString("timezone");
Log.i(TAG, "From JSON: " + timezone);
JSONObject currently = forecast.getJSONObject("currently");
Current current = new Current();
// Parse weather data from currently object
current.setHumidity(currently.getDouble("humidity"));
current.setTime(currently.getLong("time"));
current.setIcon(currently.getString("icon"));
current.setLocationLabel("Alcatraz Island, CA");
current.setPrecipChance(currently.getDouble("precipProbability"));
current.setSummary(currently.getString("summary"));
current.setTemperature(currently.getDouble("temperature"));
current.setTimeZone(timezone);
Log.d(TAG, current.getFormattedTime());
return current;
}
private boolean isNetworkAvailable() {
ConnectivityManager manager = (ConnectivityManager) getSystemService(Context.CONNECTIVITY_SERVICE);
NetworkInfo networkInfo = manager.getActiveNetworkInfo();
boolean isAvailable = false;
if (networkInfo != null && networkInfo.isConnected()) {
isAvailable = true;
}
return isAvailable;
}
private void alertUserAboutError() {
AlertDialogFragment dialog = new AlertDialogFragment();
dialog.show(getFragmentManager(), "error_dialog");
}
public void refreshOnClick(View view) {
getForecast(latitude, longitude);
Toast.makeText(this, "Refreshing data", Toast.LENGTH_LONG).show();
}
public void hourlyOnClick(View view) {
List<Hour> hours = Arrays.asList(forecast.getHourlyForecast());
Intent intent = new Intent(this, HourlyForecastActivity.class);
intent.putExtra("HourlyList", (Serializable) hours);
startActivity(intent);
}
}
这是我的堆栈跟踪
07-19 09:53:53.662 12590-12590/uk.co.jonniegrieve.stormy E/AndroidRuntime: FATAL EXCEPTION: main
Process: uk.co.jonniegrieve.stormy, PID: 12590
java.lang.IllegalStateException: Could not execute method for android:onClick
at android.support.v7.app.AppCompatViewInflater$DeclaredOnClickListener.onClick(AppCompatViewInflater.java:389)
at android.view.View.performClick(View.java:5198)
at android.view.View$PerformClick.run(View.java:21147)
at android.os.Handler.handleCallback(Handler.java:739)
at android.os.Handler.dispatchMessage(Handler.java:95)
at android.os.Looper.loop(Looper.java:148)
at android.app.ActivityThread.main(ActivityThread.java:5417)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:726)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:616)
Caused by: java.lang.reflect.InvocationTargetException
at java.lang.reflect.Method.invoke(Native Method)
at android.support.v7.app.AppCompatViewInflater$DeclaredOnClickListener.onClick(AppCompatViewInflater.java:384)
at android.view.View.performClick(View.java:5198)
at android.view.View$PerformClick.run(View.java:21147)
at android.os.Handler.handleCallback(Handler.java:739)
at android.os.Handler.dispatchMessage(Handler.java:95)
at android.os.Looper.loop(Looper.java:148)
at android.app.ActivityThread.main(ActivityThread.java:5417)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:726)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:616)
Caused by: java.lang.NullPointerException: storage == null
at java.util.Arrays$ArrayList.<init>(Arrays.java:38)
at java.util.Arrays.asList(Arrays.java:155)
at com.teamtreehouse.stormy.ui.MainActivity.hourlyOnClick(MainActivity.java:222)
at java.lang.reflect.Method.invoke(Native Method)
at android.support.v7.app.AppCompatViewInflater$DeclaredOnClickListener.onClick(AppCompatViewInflater.java:384)
at android.view.View.performClick(View.java:5198)
at android.view.View$PerformClick.run(View.java:21147)
at android.os.Handler.handleCallback(Handler.java:739)
at android.os.Handler.dispatchMessage(Handler.java:95)
at android.os.Looper.loop(Looper.java:148)
at android.app.ActivityThread.main(ActivityThread.java:5417)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:726)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:616)
07-19 09:53:53.682 1228-1228/? E/EGL_emulation: tid 1228: eglCreateSyncKHR(1881): error 0x3004 (EGL_BAD_ATTRIBUTE
)
看起来 hourlyOnClick returns 中的方法 forecast.getHourlyForecast() 为 null 而不是数组。