java.lang.ClassCastException: java.util.HashMap cannot be cast to com.foodonomic.foodonomic.Category

utkarsh-saxena · April 14, 2016, 4:37pm

java.lang.ClassCastException: java.util.HashMap cannot be cast to com.foodonomic.foodonomic.CategoryCode
My code gives this error when I use contacts.getData() to get the list, where contacts contacts is my BackendlessCollection received from server

mark-piller · April 14, 2016, 8:33pm

Add this line of code before you make any data retrieval requests:

Backendless.Data.mapTableToClass( “CategoryCode”, CategoryCode.class );

utkarsh-saxena · April 14, 2016, 9:37pm

Sorry but its not working.

Data is received in the BackendlessCollection and it shows as well when I use toString() on the received BackendlessCollection object and List<CategoryCode> code=foundContacts.getData(); this also doesn’t give any error and works fine but when I use some method for example code.toString() then it again gives me ClassCasteException. Here also if I write Log.d(“key”,code+""); it works, but writing Log.d(“key”,code.toString()) give an error.

utkarsh-saxena · April 14, 2016, 9:42pm

My table and its name matches exactly with Class that I have used. If I try to save some object it gets saved to the same table only but that time also handleFault() is called where BackendlessFault is null.

utkarsh-saxena · April 14, 2016, 9:56pm

Backendless.Data.mapTableToClass( "CategoryCode", CategoryCode.class );
Backendless.Persistence.of(CategoryCode.class).find(new AsyncCallback&lt;BackendlessCollection&lt;CategoryCode&gt;>() {
    @Override
    public void handleResponse(BackendlessCollection&lt;CategoryCode&gt; foundContacts) {

        Log.d("vivz","Inside handle response");
        List&lt;CategoryCode&gt; code=foundContacts.getData();

        Log.d("vivz",code.get(1).toString()); //Here I get That ClassCastException

        
    }

    @Override
    public void handleFault(BackendlessFault fault) {
        //Snackbar.make(coordinatorLayout,"Network error, check your internet connection",Snackbar.LENGTH_LONG).show();

        Log.d("vivz", "Error");
    }
});

mark-piller · April 14, 2016, 10:26pm

Do you have a stack trace for the exception?

utkarsh-saxena · April 14, 2016, 10:37pm

04-15 03:21:46.450 1878-1878/com.foodonomic.foodonomic E/AndroidRuntime: FATAL EXCEPTION: main
Process: com.foodonomic.foodonomic, PID: 1878
java.lang.ClassCastException: java.util.HashMap cannot be cast to com.foodonomic.foodonomic.CategoryCode
at com.foodonomic.foodonomic.Foodonomic$CustomFragmentPagerAdapter$1.handleResponse(Foodonomic.java:207)
at com.foodonomic.foodonomic.Foodonomic$CustomFragmentPagerAdapter$1.handleResponse(Foodonomic.java:200)
at com.backendless.Persistence$10.handleResponse(Persistence.java:629)
at com.backendless.Persistence$10.handleResponse(Persistence.java:621)
at com.backendless.async.message.AsyncMessage$ResponseHandler.handle(AsyncMessage.java:64)
at com.backendless.async.message.AsyncMessage.handleCallback(AsyncMessage.java:41)
at com.backendless.core.AndroidCarrier$1.handleMessage(AndroidCarrier.java:37)
at android.os.Handler.dispatchMessage(Handler.java:106)
at android.os.Looper.loop(Looper.java:193)
at android.app.ActivityThread.main(ActivityThread.java:5323)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:515)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:828)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:644)
at dalvik.system.NativeStart.main(Native Method)

mark-piller · April 14, 2016, 11:17pm

What does the CategoryCode class look like?

utkarsh-saxena · April 14, 2016, 11:23pm

package com.foodonomic.foodonomic;

import java.util.Date;
import java.util.HashMap;

/**
 * Created by .hp on 14-04-2016.
 */
public class CategoryCode {
    private String objectId;

    private String categoryName;
    private int categoryID;


    CategoryCode(){

    }



    public String getCategoryName() {
        return categoryName;
    }

    public void setCategoryName(String categoryName) {
        this.categoryName = categoryName;
    }

    public int getCategoryID() {
        return categoryID;
    }

    public void setCategoryID(int categoryID) {
        this.categoryID = categoryID;
    }

    public String getObjectId() {
        return objectId;
    }

    public void setObjectId(String objectId) {
        this.objectId = objectId;
    }
}

mark-piller · April 14, 2016, 11:27pm

Make the constructor public.

utkarsh-saxena · April 14, 2016, 11:49pm

Thnku very much Mark… I feel So dumb now, such a silly mistake i did in my code. Thanks for giving me your valuable time.

You are really very cooperative. I feel so blessed that I have people like you to help me.
Thanks once again thanks aLLLLLLLOOOT …

valeria-bommi · May 4, 2016, 5:53pm

Hello, Mark! Here is the same problem and i cant solve it. (5 days ago i didnt have it, when have made a service)
So, i use the service (Java/Android)
This is my code:

public BackendlessCollection&lt;News&gt; getNews(){ 
 return Backendless.Persistence.of( News.class).find(); 
}

This code Backendless has generated :

public void getNewsAsync(AsyncCallback&lt;BackendlessCollection&lt;News&gt;> callback) 
{ 
 Object[] args = new Object[]{}; 
 Backendless.CustomService.invoke( SERVICE_NAME, SERVICE_VERSION_NAME, "getNews", args, com.backendless.BackendlessCollection.class, callback); 
 
}

I have Activity. I have already write this

@Override 
protected void onCreate(Bundle savedInstanceState) { 
 super.onCreate(savedInstanceState); 
 setContentView(R.layout.activity_main); 
 
 NewsService.initApplication(this); 
 Backendless.Data.mapTableToClass("News", News.class); 
 newsService = NewsService.getInstance(); 
 
 makeContext(); 
}

The method where i use my service method
And here is the problem

void makeContext(){ 
 newsService.getNewsAsync(new AsyncCallback&lt;BackendlessCollection&lt;News&gt;>() { 
 @Override 
 public void handleResponse(BackendlessCollection&lt;News&gt; newsBackendlessCollection) { 
 
 Log.e("news", "d " + newsBackendlessCollection.getCurrentPage().get(0).getTitle() 
 .toString()); // HERE IS THE PROBLEM 
 Log.e("news", "d " + newsBackendlessCollection.getCurrentPage().get(0)); //HERE ALL IS GOOD 
 
 ...

My News.class is generated by Backendless. I have added the constructor

public class News { 
 private java.lang.String created; 
 private java.lang.String dateNews; 
 private int id; 
 private int idCategory; 
 private int likes; 
 private java.lang.String objectId; 
 private java.lang.String text; 
 private java.lang.String title; 
 
 public News(){} 
 
 public void setCreated(java.lang.String created) { 
 this.created = created; 
 } 
 
 public void setDateNews(java.lang.String dateNews) { this.dateNews = dateNews;} 
 
 public void setId(int id) { 
 this.id = id; 
 } 
 
 public void setIdCategory(int idCategory) { 
 this.idCategory = idCategory; 
 } 
 
 public void setLikes(int likes) { 
 this.likes = likes; 
 } 
 
 public void setObjectId(java.lang.String objectId) { 
 this.objectId = objectId; 
 } 
 
 public void setText(java.lang.String text) { 
 this.text = text; 
 } 
 
 public void setTitle(java.lang.String title) { 
 this.title = title; 
 } 
 
 public java.lang.String getCreated() { 
 return created; 
 } 
 
 public java.lang.String getDateNews() { 
 return dateNews; 
 } 
 
 public int getId() { 
 return id; 
 } 
 
 public int getIdCategory() { 
 return idCategory; 
 } 
 
 public int getLikes() { 
 return likes; 
 } 
 
 public java.lang.String getObjectId() { 
 return objectId; 
 } 
 
 public java.lang.String getText() { 
 return text; 
 } 
 
 public java.lang.String getTitle() { 
 return title; 
 } 
}

Here is the stack trace

05-04 20:37:04.019 17166-17166/? E/AndroidRuntime: FATAL EXCEPTION: main
 java.lang.ClassCastException: java.util.HashMap cannot be cast to com.bommi.inews.News
 at com.android.app.valeria.inews.MainActivity$2.handleResponse(MainActivity.java:93)
 at com.android.app.valeria.inews.MainActivity$2.handleResponse(MainActivity.java:89)
 at com.backendless.async.message.AsyncMessage$ResponseHandler.handle(AsyncMessage.java:64)
 at com.backendless.async.message.AsyncMessage.handleCallback(AsyncMessage.java:41)
 at com.backendless.core.AndroidCarrier$1.handleMessage(AndroidCarrier.java:37)
 at android.os.Handler.dispatchMessage(Handler.java:95)
 at android.os.Looper.loop(Looper.java:137)
 at android.app.ActivityThread.main(ActivityThread.java:5283)
 at java.lang.reflect.Method.invokeNative(Native Method)
 at java.lang.reflect.Method.invoke(Method.java:511)
 at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1102)
 at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:869)
 at dalvik.system.NativeStart.main(Native Method)

My packages tree
http://support.backendless.com/public/attachments/53a21f8fffc82180c6c03ed8c8620950.png</img>
Also i have updated backendless.jar

Hope i have tried all to solve the problem…
Even dont know which way i should think to solve the problem…
Regards,
Valeria

mark-piller · May 4, 2016, 6:24pm

Please let me know your app id.