gpt4 book ai didi

android - 使用 HttpResponseCache 会使应用程序崩溃

转载 作者:太空狗 更新时间:2023-10-29 13:16:19 26 4
gpt4 key购买 nike

我正在尝试使用 HttpResponseCache 来缓存网络数据,但是当我将安装缓存代码放入 OnCreateOnPause 方法时,应用崩溃。我使用了 HttpResponseCache documentation 中的代码.并出现如下所示的编译错误。使用后

@TargetApi(Build.VERSION_CODES.ICE_CREAM_SANDWICH)

为了解决错误然后它消失了,我运行应用程序但仍然崩溃。当我删除该代码时,它会恢复正常行为。

protected void onCreate(Bundle savedInstanceState) {
...

try {
File httpCacheDir = new File(context.getCacheDir(), "http");
long httpCacheSize = 10 * 1024 * 1024; // 10 MiB
HttpResponseCache.install(httpCacheDir, httpCacheSize); //error
} catch (IOException e) {
Log.i(TAG, "HTTP response cache installation failed:" + e);
}
}

protected void onStop() {
...

HttpResponseCache cache = HttpResponseCache.getInstalled();//error
if (cache != null) {
cache.flush();//error
}
}}

我是初学者,如果有人能提供帮助,我将不胜感激。这是 MainActivity 代码

    public class MainActivity extends AppCompatActivity  {


private MovieAdapter movieAdapter;
private Context context;



@TargetApi(Build.VERSION_CODES.ICE_CREAM_SANDWICH)
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);


// ------ caching data ------------------
try {
File httpCacheDir = new File(context.getCacheDir(), "http");
long httpCacheSize = 2 * 1024 * 1024; // 10 MiB
HttpResponseCache.install(httpCacheDir, httpCacheSize); //error
} catch (IOException e) {
Log.i("caching failed", "HTTP response cache installation failed:" + e);
}

//-----------------------

DataSyncTask dataSyncTask = new DataSyncTask();
dataSyncTask.execute();
}


@Override
public boolean onCreateOptionsMenu(Menu menu) {
MenuInflater inflater = getMenuInflater();
inflater.inflate(R.menu.menu_main, menu);
return true;
}



@Override
public boolean onOptionsItemSelected(MenuItem item) {
int id = item.getItemId();

if (id == R.id.action_settings) {
startActivity(new Intent(this, SettingsActivity.class));

return true;
}
return super.onOptionsItemSelected(item);
}


private class DataSyncTask extends AsyncTask<Void, Void, ArrayList<Movie>> {

@Override
protected ArrayList<Movie> doInBackground(Void... params) {
JSONHttpClient jsonHttpClient = new JSONHttpClient(MainActivity.this);
JSONDataParser finalData = new JSONDataParser();
/*
using shared preference to obtain data
*/
SharedPreferences sharedPreferences =
PreferenceManager.getDefaultSharedPreferences(getApplicationContext());

String sortingOrder = sharedPreferences.getString(
getString(R.string.pref_findMovies_key),
getString(R.string.pref_popular_value));

String streamData = jsonHttpClient.getData(sortingOrder);
return finalData.getParsedData(streamData);

}

@Override
protected void onPostExecute(final ArrayList<Movie> movies) {


movieAdapter = new MovieAdapter(getApplicationContext(), movies);
GridView gridView = (GridView) findViewById(R.id.movies_grid);
gridView.setAdapter(movieAdapter);
gridView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> adapterView, View view, int i, long l) {
Movie movie = (Movie) adapterView.getItemAtPosition(i);
Intent intent = new Intent(MainActivity.this, DetailActivity.class);
intent.putExtra("MovieTitle", movie.getTitle());
intent.putExtra("voteAverage", movie.getVoteAverage());
intent.putExtra("ReleaseDate", movie.getReleaseDate());
intent.putExtra("MovieOverview", movie.getOverview());
intent.putExtra("PosterPath", movie.getPosterPath());

startActivity(intent);
}
});

}
}

@Override
protected void onResume() {
DataSyncTask dataSyncTask = new DataSyncTask();
dataSyncTask.execute();
super.onResume();

}

@TargetApi(Build.VERSION_CODES.ICE_CREAM_SANDWICH)
@Override
protected void onStop() {
HttpResponseCache cache = HttpResponseCache.getInstalled();
if (cache != null) {
cache.flush();
}
super.onStop();
}
}

应用程序崩溃后 logcat 中出现的内容

12-19 19:22:58.465  17548-17548/com.example.geekymind.displayjsondatafrominternet W/dalvikvm﹕ VFY: unable to find class referenced in signature (Landroid/view/SearchEvent;)
12-19 19:22:58.465 17548-17548/com.example.geekymind.displayjsondatafrominternet I/dalvikvm﹕ Could not find method android.view.Window$Callback.onSearchRequested, referenced from method android.support.v7.internal.view.WindowCallbackWrapper.onSearchRequested
12-19 19:22:58.465 17548-17548/com.example.geekymind.displayjsondatafrominternet W/dalvikvm﹕ VFY: unable to resolve interface method 14585: Landroid/view/Window$Callback;.onSearchRequested (Landroid/view/SearchEvent;)Z
12-19 19:22:58.465 17548-17548/com.example.geekymind.displayjsondatafrominternet I/dalvikvm﹕ Could not find method android.view.Window$Callback.onWindowStartingActionMode, referenced from method android.support.v7.internal.view.WindowCallbackWrapper.onWindowStartingActionMode
12-19 19:22:58.465 17548-17548/com.example.geekymind.displayjsondatafrominternet W/dalvikvm﹕ VFY: unable to resolve interface method 14589: Landroid/view/Window$Callback;.onWindowStartingActionMode (Landroid/view/ActionMode$Callback;I)Landroid/view/ActionMode;
12-19 19:22:58.505 17548-17548/com.example.geekymind.displayjsondatafrominternet I/dalvikvm﹕ Could not find method android.content.res.TypedArray.getChangingConfigurations, referenced from method android.support.v7.internal.widget.TintTypedArray.getChangingConfigurations
12-19 19:22:58.505 17548-17548/com.example.geekymind.displayjsondatafrominternet W/dalvikvm﹕ VFY: unable to resolve virtual method 451: Landroid/content/res/TypedArray;.getChangingConfigurations ()I
12-19 19:22:58.515 17548-17548/com.example.geekymind.displayjsondatafrominternet I/dalvikvm﹕ Could not find method android.content.res.TypedArray.getType, referenced from method android.support.v7.internal.widget.TintTypedArray.getType
12-19 19:22:58.515 17548-17548/com.example.geekymind.displayjsondatafrominternet W/dalvikvm﹕ VFY: unable to resolve virtual method 473: Landroid/content/res/TypedArray;.getType (I)I
12-19 19:22:58.585 17548-17548/com.example.geekymind.displayjsondatafrominternet W/dalvikvm﹕ threadid=1: thread exiting with uncaught exception (group=0x415ffc80)

最佳答案

根据 HttpResponseCache Docs :

Enable caching of all of your application's HTTP requests by installing the cache at application startup.

所以你应该使用如下:

我的应用程序.java:

public class MyApplication extends Application {

private final Context mContext = this;

public void onCreate() {
super.onCreate();

// Install the cache
try {
File httpCacheDir = new File(mContext.getCacheDir(), "http");
long httpCacheSize = 10 * 1024 * 1024; // 10 MiB
HttpResponseCache.install(httpCacheDir, httpCacheSize);
} catch (IOException e) {
Log.i("CacheHttpUrlConnection", "HTTP response cache installation failed:" + e);
}

// Register for activity lifecycle callbacks,
// specifically interested in activity stop callbacks.
registerActivityLifecycleCallbacks(
new MyApplicationActivityLifeCycleCallbacks());
}

// method to flush cache contents to the filesystem
public void flushCache() {
HttpResponseCache cache = HttpResponseCache.getInstalled();
if (cache != null) {
cache.flush();
}
}

private class MyApplicationActivityLifeCycleCallbacks implements ActivityLifecycleCallbacks {
@Override
public void onActivityCreated(Activity activity, Bundle savedInstanceState) {
}

@Override
public void onActivityStarted(Activity activity) {
}

@Override
public void onActivityResumed(Activity activity) {
}

@Override
public void onActivityPaused(Activity activity) {
}

public void onActivityStopped(Activity activity) {
flushCache();
}

@Override
public void onActivitySaveInstanceState(Activity activity, Bundle outState) {
}

@Override
public void onActivityDestroyed(Activity activity) {
}
}
}

MainActivity.java:

AsyncTask 类的 doInBackground 内部:

...
URL url = new URL(address);
HttpURLConnection urlConnection = (HttpURLConnection) url.openConnection();
int maxStale = 60 * 60 * 24 * 28; // tolerate 4-weeks stale
urlConnection.addRequestProperty("Cache-Control", "max-stale=" + maxStale);
// Checks cache
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.ICE_CREAM_SANDWICH) {
cache = HttpResponseCache.getInstalled();
if (cache != null) {
cacheInfo = "Request count: "
+ cache.getRequestCount() + ", hit count "
+ cache.getHitCount() + ", network count "
+ cache.getNetworkCount() + " size = "
+ cache.size() + " <-----------------";
Log.i(LOG_TAG, cacheInfo);
}
}
// Gets stream
Log.i(LOG_TAG, "RespCode: " + urlConnection.getResponseCode());
if (urlConnection.getResponseCode() < HttpURLConnection.HTTP_BAD_REQUEST) {
inputStream = urlConnection.getInputStream();
} else {
inputStream = urlConnection.getErrorStream();
}
// Parses stream to string
BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(inputStream));
String temp, response = "";
while ((temp = bufferedReader.readLine()) != null) {
response += temp;
}
...

AndroidManifest.xml:

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.example.cachehttpurlconnection" >

<uses-permission android:name="android.permission.INTERNET" />

<application
android:allowBackup="true"
android:icon="@mipmap/ic_launcher"
android:label="@string/app_name"
android:supportsRtl="true"
android:theme="@style/AppTheme"
android:name="com.example.cachehttpurlconnection.MyApplication" >
<activity android:name=".MainActivity" >
<intent-filter>
<action android:name="android.intent.action.MAIN" />

<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
</application>

</manifest>

关于android - 使用 HttpResponseCache 会使应用程序崩溃,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/34373336/

26 4 0
Copyright 2021 - 2024 cfsdn All Rights Reserved 蜀ICP备2022000587号
广告合作:1813099741@qq.com 6ren.com