مشکل در تبدیل json

سلام من یه response از یه ادرسی دریافت میکنم 

مشکل اینجاست مثلا مثل کد پایین یه سری از id ها فیلد Album دارن ولی یسری دیگه ندارن 

"id": 100586,
      "title": "Nima Masiha - \"Payane Harfat\"",
      "explicit": false,
      "link": "https://host2.media-rj.com/media/mp3/mp3-256/100586-c4f8f2a8b0ab46c.mp3",
      "photo": "https://assets.rjassets.com/static/mp3/nima-masiha-payane-harfat/53f262f2a744c95.jpg",
      "thumbnail": "https://assets.rjassets.com/static/mp3/nima-masiha-payane-harfat/53f262f2a744c95-thumb.jpg",
      "plays": "13,985",
      "artist": "Nima Masiha",
      "song": "Payane Harfat",
      "photo_240": "https://assets.rjassets.com/static/mp3/nima-masiha-payane-harfat/53f262f2a744c95-photo_240x180.jpg",
      "likes": "59",
      "dislikes": "0",
      "downloads": "13,985",
      "photo_player": "https://assets.rjassets.com/static/mp3/nima-masiha-payane-harfat/0d94a4933725f08-player.jpg",
      "permlink": "Nima-Masiha-Payane-Harfat",
      "share_link": "https://rjapp.app/m/4qL514Nl",
      "created_at": "2021-09-18T11:45:50-04:00",
      "type": "mp3",
      "duration": 256.496,
      "hls_link": "https://host2.media-rj.com/media/mp3/mp3-hls/100586-c4f8f2a8b0ab46c/playlist.m3u8",
      "lq_link": "https://host2.media-rj.com/media/mp3/aac-128/100586-c4f8f2a8b0ab46c.m4a",
      "hq_link": "https://host2.media-rj.com/media/mp3/aac-256/100586-c4f8f2a8b0ab46c.m4a",
      "lq_hls": "https://host2.media-rj.com/media/mp3/mp3-hls/100586-c4f8f2a8b0ab46c/file-96k.m3u8",
      "hq_hls": "https://host2.media-rj.com/media/mp3/mp3-hls/100586-c4f8f2a8b0ab46c/playlist.m3u8",
      "lufs": -5.9,
      "artist_tags": [
        "Nima Masiha"
      ],
      "bg_colors": [
        "#c19b8f",
        "#976453"
      ]

"id": 100622,
      "title": "Arman Miladi & Amin Tijay, & Young Sudden - \"Gangsta\"",
      "explicit": false,
      "link": "https://host2.media-rj.com/media/mp3/mp3-256/100622-ba2f07903aabf74.mp3",
      "photo": "https://assets.rjassets.com/static/mp3/arman-miladi-amin-tijay-young-sudden-gangsta/b2a6cfac0d2ae28.jpg",
      "thumbnail": "https://assets.rjassets.com/static/mp3/arman-miladi-amin-tijay-young-sudden-gangsta/b2a6cfac0d2ae28-thumb.jpg",
      "plays": "113,477",
      "artist": "Arman Miladi & Amin Tijay, & Young Sudden",
      "song": "Gangsta",
      "photo_240": "https://assets.rjassets.com/static/mp3/arman-miladi-amin-tijay-young-sudden-gangsta/b2a6cfac0d2ae28-photo_240x180.jpg",
      "likes": "262",
      "dislikes": "2",
      "downloads": "113,477",
      "photo_player": "https://assets.rjassets.com/static/mp3/arman-miladi-amin-tijay-young-sudden-gangsta/e7cdced05eec6ab-player.jpg",
      "permlink": "Arman-Miladi-Amin-Tijay-Young-Sudden-Gangsta",
      "share_link": "https://rjapp.app/m/ZEwRZwrv",
      "created_at": "2021-09-20T06:24:46-04:00",
      "type": "mp3",
      "duration": 239.073,
      "hls_link": "https://host2.media-rj.com/media/mp3/mp3-hls/100622-ba2f07903aabf74/playlist.m3u8",
      "lq_link": "https://host2.media-rj.com/media/mp3/aac-128/100622-ba2f07903aabf74.m4a",
      "hq_link": "https://host2.media-rj.com/media/mp3/aac-256/100622-ba2f07903aabf74.m4a",
      "lq_hls": "https://host2.media-rj.com/media/mp3/mp3-hls/100622-ba2f07903aabf74/file-96k.m3u8",
      "hq_hls": "https://host2.media-rj.com/media/mp3/mp3-hls/100622-ba2f07903aabf74/playlist.m3u8",
      "lufs": -9.1,
      "album": {
        "id": 2328,
        "album": "El Quatro",
        "artist": "Arman Miladi",
        "track": 2,
        "share_link": "https://rjapp.app/ma/KwEoQGpV"
      },
      "artist_tags": [
        "Arman Miladi & Amin Tijay, & Young Sudden"
      ],
      "bg_colors": [
        "#e63629",
        "#971b12"
      ]

الان من چجوری باید این json رو به کلاس جاوا تبدیل کنم از کد زیر استاده کردم ولی جواب نداد چون یسری از ایدی ها album ندارن 

public int id;
        public String title;
        public boolean explicit;
        public String link;
        public String photo;
        public String thumbnail;
        public String plays;
        public String artist;
        public String song;
        public String photo_240;
        public String likes;
        public String dislikes;
        public String downloads;
        public String photo_player;
        public String permlink;
        public String share_link;
        public String created_at;
        public String type;
        public double duration;
        public String hls_link;
        public String lq_link;
        public String hq_link;
        public String lq_hls;
        public String hq_hls;
        public double lufs;
        public List<String> artist_tags;
        public List<String> bg_colors;
        public Album album;