関連ワード:  java stream get first and last element    java stream get first element    java stream get first element of list    java stream get first element that matches    java stream get first element of list or null    java stream get first element after filter    java stream get first element or null    java stream get first n elements    java stream get first 3 elements    java stream get first n elements of list  
結果 : java stream get first and last element