在LinearLayoutManager中設置分隔線可以通過ItemDecoration來實現。首先，你需要創建一個自定義的ItemDecoration類，并重寫它的onDraw方法來繪制分隔線。以下是一個示例代碼：

public class DividerItemDecoration extends RecyclerView.ItemDecoration {
    private Drawable mDivider;

    public DividerItemDecoration(Context context) {
        mDivider = ContextCompat.getDrawable(context, R.drawable.divider);
    }

    @Override
    public void onDraw(Canvas c, RecyclerView parent, RecyclerView.State state) {
        int left = parent.getPaddingLeft();
        int right = parent.getWidth() - parent.getPaddingRight();

        for (int i = 0; i < parent.getChildCount() - 1; i++) {
            View child = parent.getChildAt(i);
            RecyclerView.LayoutParams params = (RecyclerView.LayoutParams) child.getLayoutParams();

            int top = child.getBottom() + params.bottomMargin;
            int bottom = top + mDivider.getIntrinsicHeight();

            mDivider.setBounds(left, top, right, bottom);
            mDivider.draw(c);
        }
    }
}

然后，在你的RecyclerView中設置這個ItemDecoration：

DividerItemDecoration dividerItemDecoration = new DividerItemDecoration(recyclerView.getContext());
recyclerView.addItemDecoration(dividerItemDecoration);

這樣就可以在LinearLayoutManager中設置分隔線了。你也可以根據需求自定義分隔線的樣式和顏色。