android – RecyclerView位于工具栏下方

问题：我在CoordinatorLayout中有一个RecyclerView和一个工具栏.
RecyclerView位于工具栏下方,但不应该.

问题：如何实现RecyclerView和工具栏有一个边框？

activity_main.xml中

<?xml version="1.0" encoding="utf-8"?>
<android.support.design.widget.CoordinatorLayout xmlns:android="http://scheR_209_11845@as.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    xmlns:app="http://scheR_209_11845@as.android.com/apk/res-auto"
    android:fitsSystemWindows="true">

    <android.support.design.widget.AppBarLayout
        android:id="@+id/appBar"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:theme="@style/ThemeOverlay.AppCompat.ActionBar">

    <include
        android:id="@+id/toolbar_main"
        layout="@layout/toolbar"></include>

    </android.support.design.widget.AppBarLayout>

    <FrameLayout
        android:id="@+id/maschinelistcontainer"
        android:layout_width="match_parent"
        android:layout_height="match_parent" />

</android.support.design.widget.CoordinatorLayout>

@H_893_6@maschine_fragment.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://scheR_209_11845@as.android.com/apk/res/android"
    android:orientation="vertical"
    android:layout_width="match_parent"
    android:layout_height="match_parent">

    <android.support.v7.widget.RecyclerView
        android:id="@+id/recycler_view"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:cliPTOPadding="false"
        android:scrollbars="vertical" />

</LinearLayout>

<?xml version="1.0" encoding="utf-8"?>
<android.support.design.widget.CoordinatorLayout xmlns:android="http://scheR_209_11845@as.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    xmlns:app="http://scheR_209_11845@as.android.com/apk/res-auto"
    android:fitsSystemWindows="true">

    <android.support.design.widget.AppBarLayout
        android:id="@+id/appBar"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:theme="@style/ThemeOverlay.AppCompat.ActionBar">

    <include
        android:id="@+id/toolbar_main"
        layout="@layout/toolbar"></include>

    </android.support.design.widget.AppBarLayout>

    <android.support.v7.widget.RecyclerView
        android:id="@+id/recycler_view"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        app:layouT_Behavior = "@String/appbar_scrolling_view_behavior" />

</android.support.design.widget.CoordinatorLayout>