Get information from Sqlite and create Object 'message' returns null [duplicate]

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• What is a Null Pointer Exception, and how do I fix it? 12 answers

I have a problem trying to collect data from a SQLite database, for some reason when you insert the item to the list (RecyclerView) returns null assuming error:

java.lang.RuntimeException: Unable to start activity ComponentInfo{beta.unomasenlafamilia/beta.unomasenlafamilia.PM_MessagesActivity}: java.lang.NullPointerException: Attempt to invoke virtual method 'void beta.unomasenlafamilia.adapter.MessageAdapter.addListItem(beta.unomasenlafamilia.domain.Message, int)' on a null object reference
                                                                        at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2406)
                                                                        at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2466)
                                                                        at android.app.ActivityThread.access$1200(ActivityThread.java:152)
                                                                        at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1341)
                                                                        at android.os.Handler.dispatchMessage(Handler.java:102)
                                                                        at android.os.Looper.loop(Looper.java:135)
                                                                        at android.app.ActivityThread.main(ActivityThread.java:5538)
                                                                        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:960)
                                                                        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:755)
                                                                     Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'void beta.unomasenlafamilia.adapter.MessageAdapter.addListItem(beta.unomasenlafamilia.domain.Message, int)' on a null object reference
                                                                        at beta.unomasenlafamilia.PM_MessagesActivity.mostrarChatLocal(PM_MessagesActivity.java:457)
                                                                        at beta.unomasenlafamilia.PM_MessagesActivity.onCreate(PM_MessagesActivity.java:120)

MainActivity.class

public void showChatLocal(String userfrom,String userto) {

    //Show total num records
    int limite = h_sql.showMsgNum();
    Cursor cursor = h_sql.fetchMessages(String.valueOf(mUserFrom.getId()), String.valueOf(mUserTo.getId()));
    MessageAdapter adapter = (MessageAdapter) mRecyclerView.getAdapter();
    List<Message> messageList = new ArrayList<Message>();

    for(int i =0;i<limite;i++){

        Message m = new Message();

        m.setUserFrom(cursor.getString(cursor.getColumnIndex("id_user_from")));
        m.setUserTo(cursor.getString(cursor.getColumnIndex("id_user_to")));
        m.setMessage(cursor.getString(cursor.getColumnIndex("message")));
        m.setRegTime(Long.parseLong(cursor.getString(cursor.getColumnIndex("regtime"))));
        m.setWasRead(Integer.parseInt(cursor.getString(cursor.getColumnIndex("wasRead"))));

        messageList.add(m);
        adapter.addListItem(messageList.get(i),0);
        mRecyclerView.smoothScrollToPosition(0);
        cursor.moveToNext();
    }

    cursor.close();
}

//MessageAdapter

public void addListItem(Message m, int position) {
    mList.add(position, m);
    notifyItemInserted(position);
}

Thank you very much to all, regards!