Serializing कस्टम वस्तु JSON

Question

में वस्तुओं एक दूसरे गतिविधि है कि एक वस्तु है और यह भंडार एक ArrayList में एक Singleton मैं जब निर्माण Activity से पहले Activity की ओर लौटने यह त्रुटि प्राप्त के अंदर पैदा करता है चलाने के बाद।

Logcat:

public void storeGlobalData(Context context){ 
    mPrefs = context.getSharedPreferences("com.nanospark.cnc", Context.MODE_PRIVATE); 
    preferenceEditor = mPrefs.edit(); 
    Gson gson = new Gson(); 
    //Transform the ArrayLists into JSON Data. 
    String machineProfileListJSON = gson.toJson(getMachineProfileList()); 
    String contactInfoListJSON = gson.toJson(getContactInfoList()); 
    String eventInfoListJSON = gson.toJson(getEventInfoList()); 
    preferenceEditor.putString("machineProfileListJSONData", machineProfileListJSON); 
    preferenceEditor.putString("contactInfoListJSONData", contactInfoListJSON); 
    preferenceEditor.putString("eventInfoListJSONData", eventInfoListJSON); 
    //Commit the changes. 
    preferenceEditor.commit(); 

} 
public void retrieveGlobalDataFromStorage(Context context){ 
    mPrefs = context.getSharedPreferences("com.nanospark.cnc", Context.MODE_PRIVATE); 
    if(mPrefs.contains("machineProfileListJSONData")){ 

     Gson gson = new Gson(); 
     String machineProfileListJSON = mPrefs.getString("machineProfileListJSONData", ""); 
     String contactInfoListJSON = mPrefs.getString("contactInfoListJSONData", ""); 
     String eventInfoListJSON = mPrefs.getString("eventInfoListJSONData", ""); 
      Type machineProfileListType = new TypeToken<ArrayList<MachineProfile>>() {}.getType(); 
      machineProfileList = (gson.fromJson(machineProfileListJSON, machineProfileListType)); 

      Type contactInfoListType = new TypeToken<ArrayList<ContactInfo>>() {}.getType(); 
      contactInfoList = gson.fromJson(contactInfoListJSON, contactInfoListType); 

      Type eventListType = new TypeToken<ArrayList<Event>>() {}.getType(); 
      eventInfoList = gson.fromJson(eventInfoListJSON, eventListType); 
    } 
} 

रिपोर्ट इवेंट वर्ग है कि लिखे जाने की कोशिश कर रहा है:

package com.nanospark.cnc; 

import java.util.ArrayList; 

import org.joda.time.LocalDate; 
import org.joda.time.LocalTime; 
public class ReportEvent extends Event { 

    public ReportEvent(String eventTitle,String eventDescription,int assignedPin, String trackingType, 
      LocalDate startDate, LocalDate endDate, boolean watchAllDay, 
      LocalTime startTime, LocalTime endTime, ArrayList<String> selectedDays, 
      ArrayList<ContactInfo> selectedContact, String formatChoice, 
      ReportTimeSpec reportTimingConfig) { 
     super(eventTitle,eventDescription, assignedPin, trackingType, startDate, endDate, watchAllDay, 
       startTime, endTime, selectedDays, selectedContact, formatChoice, 
       reportTimingConfig); 
     // TODO Auto-generated constructor stub 
    } 

} 

जेनेरिक घटना क्लास कि रिपोर्ट घटना

10-09 15:00:48.125: E/AndroidRuntime(4266): FATAL EXCEPTION: main 
10-09 15:00:48.125: E/AndroidRuntime(4266): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.nanospark.cnc/com.nanospark.cnc.ContactCreateActivity}: java.lang.RuntimeException: Failed to invoke public org.joda.time.Chronology() with no args 
10-09 15:00:48.125: E/AndroidRuntime(4266):  at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2211) 
10-09 15:00:48.125: E/AndroidRuntime(4266):  at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2261) 
10-09 15:00:48.125: E/AndroidRuntime(4266):  at android.app.ActivityThread.access$600(ActivityThread.java:141) 
10-09 15:00:48.125: E/AndroidRuntime(4266):  at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1256) 
10-09 15:00:48.125: E/AndroidRuntime(4266):  at android.os.Handler.dispatchMessage(Handler.java:99) 
10-09 15:00:48.125: E/AndroidRuntime(4266):  at android.os.Looper.loop(Looper.java:137) 
10-09 15:00:48.125: E/AndroidRuntime(4266):  at android.app.ActivityThread.main(ActivityThread.java:5103) 
10-09 15:00:48.125: E/AndroidRuntime(4266):  at java.lang.reflect.Method.invokeNative(Native Method) 
10-09 15:00:48.125: E/AndroidRuntime(4266):  at java.lang.reflect.Method.invoke(Method.java:525) 
10-09 15:00:48.125: E/AndroidRuntime(4266):  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:737) 
10-09 15:00:48.125: E/AndroidRuntime(4266):  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:553) 
10-09 15:00:48.125: E/AndroidRuntime(4266):  at dalvik.system.NativeStart.main(Native Method) 
10-09 15:00:48.125: E/AndroidRuntime(4266): Caused by: java.lang.RuntimeException: Failed to invoke public org.joda.time.Chronology() with no args 
10-09 15:00:48.125: E/AndroidRuntime(4266):  at com.google.gson.internal.ConstructorConstructor$3.construct(ConstructorConstructor.java:107) 
10-09 15:00:48.125: E/AndroidRuntime(4266):  at com.google.gson.internal.bind.ReflectiveTypeAdapterFactory$Adapter.read(ReflectiveTypeAdapterFactory.java:173) 
10-09 15:00:48.125: E/AndroidRuntime(4266):  at com.google.gson.internal.bind.ReflectiveTypeAdapterFactory$1.read(ReflectiveTypeAdapterFactory.java:95) 
10-09 15:00:48.125: E/AndroidRuntime(4266):  at com.google.gson.internal.bind.ReflectiveTypeAdapterFactory$Adapter.read(ReflectiveTypeAdapterFactory.java:183) 
10-09 15:00:48.125: E/AndroidRuntime(4266):  at com.google.gson.internal.bind.ReflectiveTypeAdapterFactory$1.read(ReflectiveTypeAdapterFactory.java:95) 
10-09 15:00:48.125: E/AndroidRuntime(4266):  at com.google.gson.internal.bind.ReflectiveTypeAdapterFactory$Adapter.read(ReflectiveTypeAdapterFactory.java:183) 
10-09 15:00:48.125: E/AndroidRuntime(4266):  at com.google.gson.internal.bind.TypeAdapterRuntimeTypeWrapper.read(TypeAdapterRuntimeTypeWrapper.java:40) 
10-09 15:00:48.125: E/AndroidRuntime(4266):  at com.google.gson.internal.bind.CollectionTypeAdapterFactory$Adapter.read(CollectionTypeAdapterFactory.java:81) 
10-09 15:00:48.125: E/AndroidRuntime(4266):  at com.google.gson.internal.bind.CollectionTypeAdapterFactory$Adapter.read(CollectionTypeAdapterFactory.java:60) 
10-09 15:00:48.125: E/AndroidRuntime(4266):  at com.google.gson.Gson.fromJson(Gson.java:805) 
10-09 15:00:48.125: E/AndroidRuntime(4266):  at com.google.gson.Gson.fromJson(Gson.java:770) 
10-09 15:00:48.125: E/AndroidRuntime(4266):  at com.google.gson.Gson.fromJson(Gson.java:719) 
10-09 15:00:48.125: E/AndroidRuntime(4266):  at com.nanospark.cnc.GlobalData.retrieveGlobalDataFromStorage(GlobalData.java:92) 
10-09 15:00:48.125: E/AndroidRuntime(4266):  at com.nanospark.cnc.ContactCreateActivity.onCreate(ContactCreateActivity.java:38) 
10-09 15:00:48.125: E/AndroidRuntime(4266):  at android.app.Activity.performCreate(Activity.java:5133) 
10-09 15:00:48.125: E/AndroidRuntime(4266):  at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1087) 
10-09 15:00:48.125: E/AndroidRuntime(4266):  at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2175) 
10-09 15:00:48.125: E/AndroidRuntime(4266):  ... 11 more 
10-09 15:00:48.125: E/AndroidRuntime(4266): Caused by: java.lang.InstantiationException: can't instantiate class org.joda.time.Chronology 
10-09 15:00:48.125: E/AndroidRuntime(4266):  at java.lang.reflect.Constructor.constructNative(Native Method) 
10-09 15:00:48.125: E/AndroidRuntime(4266):  at java.lang.reflect.Constructor.newInstance(Constructor.java:417) 
10-09 15:00:48.125: E/AndroidRuntime(4266):  at com.google.gson.internal.ConstructorConstructor$3.construct(ConstructorConstructor.java:104) 
10-09 15:00:48.125: E/AndroidRuntime(4266):  ... 27 more 

सिंगलटन कोड JSON लेखन कर रही विस्तारित करता है:

package com.nanospark.cnc; 

import java.util.ArrayList; 
import java.util.Calendar; 

import org.joda.time.LocalDate; 
import org.joda.time.LocalTime; 


public class Event { 
    String eventTitle; 
    String eventDescription; 
    int assignedPin; 
    String trackingType; 
    LocalDate startDate; 
    LocalDate endDate; 
    boolean watchAllDay; 
    LocalTime startTime; 
    LocalTime endTime; 
    ArrayList<String> selectedDays = new ArrayList<String>(); 
    ArrayList<ContactInfo> selectedContact = new ArrayList<ContactInfo>(); 
    String formatChoice; 
    ReportTimeSpec reportTimingConfigs; 

    public Event(){ 

    } 
    public Event(String eventTitle, String eventDescription, int assignedPin, String trackingType, 
      LocalDate startDate, LocalDate endDate, boolean watchAllDay, 
      LocalTime startTime, LocalTime endTime, ArrayList<String> selectedDays, 
      ArrayList<ContactInfo> selectedContact, String formatChoice, ReportTimeSpec reportTimingConfigs) { 
     this.eventTitle = eventTitle; 
     this.eventDescription = eventDescription; 
     this.assignedPin = assignedPin; 
     this.trackingType = trackingType; 
     this.startDate = startDate; 
     this.endDate = endDate; 
     this.watchAllDay = watchAllDay; 
     this.startTime = startTime; 
     this.endTime = endTime; 
     this.selectedDays = selectedDays; 
     this.selectedContact = selectedContact; 
     this.formatChoice = formatChoice; 
     this.reportTimingConfigs = reportTimingConfigs; 
    } 



    public String getEventTitle() { 
     return eventTitle; 
    } 

    public void setEventTitle(String eventTitle) { 
     this.eventTitle = eventTitle; 
    } 

    public String getEventDescription() { 
     return eventDescription; 
    } 

    public void setEventDescription(String eventDescription) { 
     this.eventDescription = eventDescription; 
    } 

    public ReportTimeSpec getReportTimingConfigs() { 
     return reportTimingConfigs; 
    } 

    public void setReportTimingConfigs(ReportTimeSpec reportTimingConfigs) { 
     this.reportTimingConfigs = reportTimingConfigs; 
    } 

    public int getAssignedPin() { 
     return assignedPin; 
    } 

    public void setAssignedPin(int assignedPin) { 
     this.assignedPin = assignedPin; 
    } 

    public String getTrackingType() { 
     return trackingType; 
    } 

    public void setTrackingType(String trackingType) { 
     this.trackingType = trackingType; 
    } 

    public LocalDate getStartDate() { 
     return startDate; 
    } 

    public void setStartDate(LocalDate startDate) { 
     this.startDate = startDate; 
    } 

    public LocalDate getEndDate() { 
     return endDate; 
    } 

    public void setEndDate(LocalDate endDate) { 
     this.endDate = endDate; 
    } 

    public boolean isWatchAllDay() { 
     return watchAllDay; 
    } 

    public void setWatchAllDay(boolean watchAllDay) { 
     this.watchAllDay = watchAllDay; 
    } 

    public LocalTime getStartTime() { 
     return startTime; 
    } 

    public void setStartTime(LocalTime startTime) { 
     this.startTime = startTime; 
    } 

    public LocalTime getEndTime() { 
     return endTime; 
    } 

    public void setEndTime(LocalTime endTime) { 
     this.endTime = endTime; 
    } 

    public ArrayList<String> getSelectedDays() { 
     return selectedDays; 
    } 

    public void setSelectedDays(ArrayList<String> selectedDays) { 
     this.selectedDays = selectedDays; 
    } 

    public ArrayList<ContactInfo> getSelectedContact() { 
     return selectedContact; 
    } 

    public void setSelectedContact(ArrayList<ContactInfo> selectedContact) { 
     this.selectedContact = selectedContact; 
    } 

    public String getFormatChoice() { 
     return formatChoice; 
    } 

    public void setFormatChoice(String formatChoice) { 
     this.formatChoice = formatChoice; 
    } 

    public ReportTimeSpec getReportTimeSpec() { 
     return reportTimingConfigs; 
    } 

    public void setReportTimeSpec(ReportTimeSpec reportTimingConfigs) { 
     this.reportTimingConfigs = reportTimingConfigs; 
    } 
    @Override 
    public String toString(){ 
     return this.eventTitle; 
    } 

} 

Answer 1

https://github.com/gkopff/gson-javatime-serialisers से कन्वर्टर्स जावा के समय जावा 8 से कक्षाएं हैं, उदा। java.time.LocalDate।

लेकिन आपको 312 लाइब्रेरी से org.joda.time कक्षाओं के लिए कन्वर्टर्स की आवश्यकता है।

कनवर्टर के लिए org.joda.time.LocalDate

public class LocalDateSerializer implements JsonDeserializer<LocalDate>, JsonSerializer<LocalDate> 
{ 
    private static final DateTimeFormatter DATE_FORMAT = ISODateTimeFormat.date(); 

    @Override 
    public LocalDate deserialize(final JsonElement je, final Type type, 
          final JsonDeserializationContext jdc) throws JsonParseException 
    { 
     final String dateAsString = je.getAsString(); 
     if (dateAsString.length() == 0) 
     { 
     return null; 
     } 
     else 
     { 
     return DATE_FORMAT.parseLocalDate(dateAsString);   
     } 
    } 

    @Override 
    public JsonElement serialize(final LocalDate src, final Type typeOfSrc, 
           final JsonSerializationContext context) 
    { 
     String retVal; 
     if (src == null) 
     { 
     retVal = ""; 
     } 
     else 
     { 
     retVal = DATE_FORMAT.print(src); 
     } 
     return new JsonPrimitive(retVal); 
    } 
} 

के लिए कनवर्टर org.joda.time.LocalTime

public class LocalTimeSerializer implements JsonDeserializer<LocalTime>, JsonSerializer<LocalTime> 
{ 

    private static final DateTimeFormatter TIME_FORMAT = ISODateTimeFormat.timeNoMillis(); 

    @Override 
    public LocalTime deserialize(final JsonElement je, final Type type, 
          final JsonDeserializationContext jdc) throws JsonParseException 
    { 
     final String dateAsString = je.getAsString(); 
     if (dateAsString.length() == 0) 
     { 
     return null; 
     } 
     else 
     { 
     return TIME_FORMAT.parseLocalTime(dateAsString);   
     } 
    } 

    @Override 
    public JsonElement serialize(final LocalTime src, final Type typeOfSrc, 
           final JsonSerializationContext context) 
    { 
     String retVal; 
     if (src == null) 
     { 
     retVal = ""; 
     } 
     else 
     { 
     retVal = TIME_FORMAT.print(src); 
     } 
     return new JsonPrimitive(retVal); 
    } 

} 

: आप कस्टम कन्वर्टर्स इसके लिए तरह बना सकते हैं, उपयोग

public void retrieveGlobalDataFromStorage(Context context) 
{ 
// ... 

    final GsonBuilder builder = new GsonBuilder() 
     .registerTypeAdapter(LocalDate.class, new LocalDateSerializer()) 
     .registerTypeAdapter(LocalTime.class, new LocalTimeSerializer()); 
    final Gson gson = builder.create(); 
// ...