当我测试我的应用程序时，关闭应用程序和清理内存（在我的情况下，CleanMaster应用程序），然后再次重新打开它，它强制关闭。我尝试搜索原因，但无法找到可解决的解决方案。
如果不是干净的记忆，它可以正常工作。我想知道在这些事件发生后是否需要保存和恢复。我非常喜欢Android。
这是log
06-29 11:59:19.479 22283-22283/com.thaifasttel D/WebView﹕ onTrimMemory: 20
06-29 11:59:33.985 22524-22524/com.thaifasttel D/jdwp﹕ sendBufferedRequest : len=0x39
06-29 11:59:33.993 22524-22524/com.thaifasttel W/asset﹕ AssetManager-->addDefaultAssets CIP path not exsit!
06-29 11:59:34.050 22524-22524/com.thaifasttel D/dalvikvm﹕ newInstance failed: no <init>()
06-29 11:59:34.052 22524-22524/com.thaifasttel D/AndroidRuntime﹕ Shutting down VM
06-29 11:59:34.052 22524-22524/com.thaifasttel W/dalvikvm﹕ threadid=1: thread exiting with uncaught exception (group=0x40d6f9a8)
06-29 11:59:34.060 22524-22524/com.thaifasttel E/AndroidRuntime﹕ FATAL EXCEPTION: main
java.lang.RuntimeException: Unable to start activity ComponentInfo{com.thaifasttel/com.thaifasttel.MainActivity}: android.support.v4.app.Fragment$InstantiationException: Unable to instantiate fragment com.thaifasttel.MainActivity$PlaceholderFragment: make sure class name exists, is public, and has an empty constructor that is public
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2343)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2395)
at android.app.ActivityThread.access$600(ActivityThread.java:162)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1364)
at android.os.Handler.dispatchMessage(Handler.java:107)
at android.os.Looper.loop(Looper.java:194)
at android.app.ActivityThread.main(ActivityThread.java:5371)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:525)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:833)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:600)
at dalvik.system.NativeStart.main(Native Method)
Caused by: android.support.v4.app.Fragment$InstantiationException: Unable to instantiate fragment com.thaifasttel.MainActivity$PlaceholderFragment: make sure class name exists, is public, and has an empty constructor that is public
at android.support.v4.app.Fragment.instantiate(Fragment.java:413)
at android.support.v4.app.FragmentState.instantiate(Fragment.java:97)
at android.support.v4.app.FragmentManagerImpl.restoreAllState(FragmentManager.java:1801)
at android.support.v4.app.FragmentActivity.onCreate(FragmentActivity.java:213)
at android.support.v7.app.ActionBarActivity.onCreate(ActionBarActivity.java:97)
at com.thaifasttel.MainActivity.onCreate(MainActivity.java:73)
at android.app.Activity.performCreate(Activity.java:5122)
at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1081)
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2307)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2395)
at android.app.ActivityThread.access$600(ActivityThread.java:162)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1364)
at android.os.Handler.dispatchMessage(Handler.java:107)
at android.os.Looper.loop(Looper.java:194)
at android.app.ActivityThread.main(ActivityThread.java:5371)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:525)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:833)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:600)
at dalvik.system.NativeStart.main(Native Method)
Caused by: java.lang.InstantiationException: can't instantiate class com.thaifasttel.MainActivity$PlaceholderFragment; no empty constructor
at java.lang.Class.newInstanceImpl(Native Method)
at java.lang.Class.newInstance(Class.java:1319)
at android.support.v4.app.Fragment.instantiate(Fragment.java:402)
at android.support.v4.app.FragmentState.instantiate(Fragment.java:97)
at android.support.v4.app.FragmentManagerImpl.restoreAllState(FragmentManager.java:1801)
at android.support.v4.app.FragmentActivity.onCreate(FragmentActivity.java:213)
at android.support.v7.app.ActionBarActivity.onCreate(ActionBarActivity.java:97)
at com.thaifasttel.MainActivity.onCreate(MainActivity.java:73)
at android.app.Activity.performCreate(Activity.java:5122)
at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1081)
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2307)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2395)
at android.app.ActivityThread.access$600(ActivityThread.java:162)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1364)
at android.os.Handler.dispatchMessage(Handler.java:107)
at android.os.Looper.loop(Looper.java:194)
at android.app.ActivityThread.main(ActivityThread.java:5371)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:525)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:833)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:600)
at dalvik.system.NativeStart.main(Native Method)
MainActivity.java
public class MainActivity extends ActionBarActivity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
if (savedInstanceState == null) {
getSupportFragmentManager().beginTransaction()
.add(R.id.container, new PlaceholderFragment())
.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();
return id == R.id.action_settings || super.onOptionsItemSelected(item);
}
public class PlaceholderFragment extends Fragment {
public PlaceholderFragment() {
}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
Log.e("My App", "onCreateView");
View rootView = inflater.inflate(R.layout.fragment_main, container, false);
return rootView;
}
WebView myWebView;
RelativeLayout splash_view;
TextView splash_text;
SharedPreferences Usettings;
String lang="th";
int isloadwa=0;
AssetManager assetPath = getAssets();
String waAssetPath ="web";
String wabase=getApplicationContext().getFilesDir().getPath();
String waIntPath = "web";
String waIntPath2 = wabase+"/"+waIntPath;
String baseupdatefolder="http://www.test.com/test/webapp";
@Override
public void onActivityCreated(Bundle savedInstanceState) {
super.onActivityCreated(savedInstanceState);
Log.e("My App", "onActivityCreated");
myWebView = (WebView) getView().findViewById(R.id.webview);
splash_view = (RelativeLayout) getView().findViewById(R.id.splashview);
splash_text = (TextView) getView().findViewById(R.id.splash_status);
inituserPref();
copydir();
}
@Override
public void onStart(){
super.onStart();
Log.e("My App", "onstart");
}
@Override
public void onResume(){
super.onResume();
Log.e("My App", "onResume");
if(isloadwa==1) {
if (isConnected()) {
Log.e("My App", "check update in app");
splash_text.setText(a_check_update);
checkupdate();
}
}
}
// do a lot of method after this