Got nullpointer when trying to pass object to activity

Question

I'm making a simple Android application for a project. I have an activity that show a List View of conversation and when I click on one of the listed conversation I want to show messages in it. For this purpose I used a Parcelable object.

import android.content.Context;
import android.os.Parcel;
import android.os.Parcelable;
import android.widget.Toast;

import java.util.concurrent.ConcurrentHashMap;

public class ParcelableChat implements Parcelable {
private Chat c;


public Chat getChat (){
    return this.c;
}

public ParcelableChat(Chat c){
    this.c = c;
}

public ParcelableChat(Parcel in){
    c = new Chat();
    c.setObject(in.readString());
    c.setMessageManager((MessageManager)in.readParcelable(MessageManager.class.getClassLoader()));

}

public static final Creator<ParcelableChat> CREATOR =
        new ClassLoaderCreator<ParcelableChat>() {

            @Override
            public ParcelableChat createFromParcel(Parcel parcel) {
                return new ParcelableChat(parcel);
            }

            @Override
            public ParcelableChat[] newArray(int i) {
                return new ParcelableChat[i];
            }

            @Override
            public ParcelableChat createFromParcel(Parcel parcel, ClassLoader classLoader) {
                return new ParcelableChat(parcel);
            }
        };

@Override
public int describeContents() {
    return 0;
}

@Override
public void writeToParcel(Parcel parcel, int i) {

}

 }

In the mainActivity I do:

 intent intent = new Intent(this,MessageActivity.class);
 intent.putExtra("chat", new ParcelableChat(item));//Where item is the Chat object from the ListView.  
 startActivity(intent);

In the new Activity (MessageActivity) I do:

 Bundle extras = getIntent().getExtras();
 ParcelableChat parcelableChat= (ParcelableChat)extras.getParcelable("chat");
 Chat chat = parcelableChat.getChat();

and when I try to display chat's last message using :

       Toast.makeText(getApplicationContext(),"Value : "+ chat.getLastMessage(),Toast.LENGTH_SHORT ).show();

LogCat:

        Process: project.ingsw.maboo, PID: 31172
        java.lang.RuntimeException: Unable to start activity ComponentInfo{project.ingsw.maboo/project.ingsw.maboo.MessageActivity}: java.lang.NullPointerException
      at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2212)
      at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2271)
      at android.app.ActivityThread.access$800(ActivityThread.java:144)
      at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1205)
      at android.os.Handler.dispatchMessage(Handler.java:102)
      at android.os.Looper.loop(Looper.java:136)
      at android.app.ActivityThread.main(ActivityThread.java:5146)
      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:732)
      at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:566)
      at dalvik.system.NativeStart.main(Native Method)
    Caused by: java.lang.NullPointerException
      at project.ingsw.maboo.Chat.getMessage(Chat.java:36)
      at project.ingsw.maboo.MessageActivity.onCreate(MessageActivity.java:37)
      at android.app.Activity.performCreate(Activity.java:5231)
      at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1087)
      at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2169)
      at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2271)
      at android.app.ActivityThread.access$800(ActivityThread.java:144)
      at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1205)
      at android.os.Handler.dispatchMessage(Handler.java:102)
      at android.os.Looper.loop(Looper.java:136)
      at android.app.ActivityThread.main(ActivityThread.java:5146)
      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:732)
      at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:566)
      at dalvik.system.NativeStart.main(Native Method)

I get NullPointerExeption.... what's the problem ?

try to use onNewIntent(Intent) – Syed Raza Mehdi Jan 20 '15 at 12:26 — Syed Raza Mehdi, Jan 20 '15 at 12:26

score 0 · Answer 1 · answered Jan 20 '15 at 12:26

0

Just Modify your new activity like this:

ParcelableChat parcelableChat= (ParcelableChat)getIntent().getParcelableExtra("chat");
Chat chat = parcelableChat.getChat();

the problem is while starting activity you are attaching tha parcelable to intent but while getting you are reading from extras. so you are getting null there.

answered Jan 20 '15 at 12:26

Rathan Kumar

2,567
2
17
24

in which line you are getting? – Rathan Kumar Jan 20 '15 at 12:51

Got nullpointer when trying to pass object to activity

1 Answers1