Hi there. I've been searching for a simple example of this with no luck.

In my android application I have two activities: 1. The main activity which is launched at startup 2. A second activity which is launched by pressing a button on the main activty.

When the second activity is finished (by pressing a button) I want it to send back an ArrayList of type MyObject to the main activity and close itself, which the main activity can then do whatever with it. How would I go about achieving this? I have been trying a few things but it is crashing my application when I start the second activity.

When the user presses button to launch second activity:

            Intent i = new Intent(MainActivity.this, secondactivity.class);
            startActivityForResult(i, 1);

The array which is bundled back after pressing a button on the second activity:

Intent intent= getIntent();
                    Bundle b = new Bundle();
                    b.putParcelableArrayList("myarraylist", mylist);
                    intent.putExtras(b);
                    setResult(RESULT_OK, intent);
                    finish();

And finally a listener on the main activity (although I'm not sure of 100% when this code launches...)

    protected void onActivityResult(int requestCode, int resultCode, Intent data) {
          super.onActivityResult(requestCode, resultCode, data);
          if(resultCode==RESULT_OK && requestCode==1){
        Bundle extras = data.getExtras();

        final ArrayList<MyObject> mylist = extras.getParcelableArrayList("myarraylist");
        Toast.makeText(MainActivity.this, mylist.get(0).getName(), Toast.LENGTH_SHORT).show();
    }
}

Any ideas where I am going wrong? The onActivityResult() seems to be crashing my application.

EDIT: This is my class MyObject, its called plan and has a name and an id

import android.os.Parcel;
import android.os.Parcelable;

public class Plan implements Parcelable{
    private String name;
    private String id;

    public Plan(){
    }

    public Plan(String name, String id){
        this.name = name;
        this.id = id;
    }


    public String getName(){
        return name;
    }
    public void setName(String name){
        this.name = name;
    }
    public String getId(){
        return id;
    }
    public void setId(String id){
        this.id = id;
    }

    public String toString(){
        return "Plan ID: " + id + " Plan Name: " + name;
    }

    @Override
    public int describeContents() {
        // TODO Auto-generated method stub
        return 0;
    }

    @Override
    public void writeToParcel(Parcel dest, int flags) {
        dest.writeString(id);
        dest.writeString(name);
    }

    public static final Parcelable.Creator<Plan> CREATOR
    = new Parcelable.Creator<Plan>() {
        public Plan createFromParcel(Parcel in) {
            return new Plan();
        }

        @Override
        public Plan[] newArray(int size) {
            // TODO Auto-generated method stub
            return new Plan[size];
        }

    };

}

This is my logcat

E/AndroidRuntime(  293): java.lang.RuntimeException: Unable to instantiate activ
ity ComponentInfo{com.daniel.android.groupproject/com.me.android.projec
t.secondactivity}: java.lang.NullPointerException
E/AndroidRuntime(  293):        at android.app.ActivityThread.performLaunchActiv
ity(ActivityThread.java:2417)
E/AndroidRuntime(  293):        at android.app.ActivityThread.handleLaunchActivi
ty(ActivityThread.java:2512)
E/AndroidRuntime(  293):        at android.app.ActivityThread.access$2200(Activi
tyThread.java:119)
E/AndroidRuntime(  293):        at android.app.ActivityThread$H.handleMessage(Ac
tivityThread.java:1863)
E/AndroidRuntime(  293):        at android.os.Handler.dispatchMessage(Handler.ja
va:99)
E/AndroidRuntime(  293):        at android.os.Looper.loop(Looper.java:123)
E/AndroidRuntime(  293):        at android.app.ActivityThread.main(ActivityThrea
d.java:4363)
E/AndroidRuntime(  293):        at java.lang.reflect.Method.invokeNative(Native
Method)
E/AndroidRuntime(  293):        at java.lang.reflect.Method.invoke(Method.java:5
21)
E/AndroidRuntime(  293):        at com.android.internal.os.ZygoteInit$MethodAndA
rgsCaller.run(ZygoteInit.java:860)
E/AndroidRuntime(  293):        at com.android.internal.os.ZygoteInit.main(Zygot
eInit.java:618)
E/AndroidRuntime(  293):        at dalvik.system.NativeStart.main(Native Method)

E/AndroidRuntime(  293): Caused by: java.lang.NullPointerException
E/AndroidRuntime(  293):        at com.daniel.android.groupproject.login.<init>(
login.java:51)
E/AndroidRuntime(  293):        at java.lang.Class.newInstanceImpl(Native Method
)
E/AndroidRuntime(  293):        at java.lang.Class.newInstance(Class.java:1479)
E/AndroidRuntime(  293):        at android.app.Instrumentation.newActivity(Instr
umentation.java:1021)
E/AndroidRuntime(  293):        at android.app.ActivityThread.performLaunchActiv
ity(ActivityThread.java:2409)
E/AndroidRuntime(  293):        ... 11 more