how make an entity for store multiple arrays using spring boot?

const [addRooms, setAddRoom] = useState([
        { room: 'G-Room',roomSquare: 0},
        
    ]);

output:-

• {room: 'G-Room', roomSquare: '04555'}

• {room: 'G-Room', roomSquare: '056565'}

• {room: 'G-Room', roomSquare: '05656566'}

• {room: 'G-Room', roomSquare: '878'}

• how to make an entity to store those arrays using spring boot ?