java.lang.NullPointerException, Attempt to read from field on a null object reference, on an Android app

I need to add the share feature to my Android app (The app is for writing notes and store them in a SQLite database) (The share button only shares the body of the note). I did it, but when I press "Share" button, it shows FC (Force Close) and the app stops.

The code of the share feature:

...
@Override
    public boolean onContextItemSelected(final MenuItem item) {
        switch (item.getItemId()) {
            case R.id.share:
                String shareBody = NotesModel.actualNote.body;
                Intent shareIntent = new Intent("android.intent.action.SEND");
                shareIntent.setType("text/plain");
                shareIntent.putExtra("android.intent.extra.TEXT", shareBody);
                startActivity(shareIntent);
                return true;
                ...

The NotesModel class:

package com.twitter.i_droidi.mynotesdonation;

public class NotesModel {

    int id;
    String title;
    String body;
    static NotesModel actualNote;

    public int getId() {
        return id;
    }

    public void setId(int id) {
        this.id = id;
    }

    public String getTitle() {
        return title;
    }

    public void setTitle(String title) {
        this.title = title;
    }

    public String getBody() {
        return body;
    }

    public void setBody(String body) {
        this.body = body;
    }
}

The logcat:

09-06 01:53:10.263  24553-24553/com.twitter.i_droidi.mynotesdonation E/AndroidRuntime﹕ FATAL EXCEPTION: main
    Process: com.twitter.i_droidi.mynotesdonation, PID: 24553
    java.lang.NullPointerException: Attempt to read from field 'java.lang.String com.twitter.i_droidi.mynotesdonation.NotesModel.body' on a null object reference
            at com.twitter.i_droidi.mynotesdonation.MainActivity.onContextItemSelected(MainActivity.java:144)
            at android.app.Activity.onMenuItemSelected(Activity.java:2905)
            at android.support.v4.app.FragmentActivity.onMenuItemSelected(FragmentActivity.java:325)
            at android.support.v7.app.AppCompatActivity.onMenuItemSelected(AppCompatActivity.java:147)
            at android.support.v7.internal.view.WindowCallbackWrapper.onMenuItemSelected(WindowCallbackWrapper.java:100)
            at com.android.internal.policy.impl.PhoneWindow$DialogMenuCallback.onMenuItemSelected(PhoneWindow.java:4701)
            at com.android.internal.view.menu.MenuBuilder.dispatchMenuItemSelected(MenuBuilder.java:761)
            at com.android.internal.view.menu.MenuItemImpl.invoke(MenuItemImpl.java:152)
            at com.android.internal.view.menu.MenuBuilder.performItemAction(MenuBuilder.java:904)
            at com.android.internal.view.menu.MenuBuilder.performItemAction(MenuBuilder.java:894)
            at com.android.internal.view.menu.MenuDialogHelper.onClick(MenuDialogHelper.java:167)
            at com.android.internal.app.AlertController$AlertParams$3.onItemClick(AlertController.java:1082)
            at android.widget.AdapterView.performItemClick(AdapterView.java:305)
            at android.widget.AbsListView.performItemClick(AbsListView.java:1146)
            at android.widget.AbsListView$PerformClick.run(AbsListView.java:3053)
            at android.widget.AbsListView$3.run(AbsListView.java:3860)
            at android.os.Handler.handleCallback(Handler.java:739)
            at android.os.Handler.dispatchMessage(Handler.java:95)
            at android.os.Looper.loop(Looper.java:135)
            at android.app.ActivityThread.main(ActivityThread.java:5254)
            at java.lang.reflect.Method.invoke(Native Method)
            at java.lang.reflect.Method.invoke(Method.java:372)
            at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:903)
            at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:698)