我无法使用post volley android从嵌套的json对象中提取数据

{
"success": true,
"message": {
"user": {
  "firstName": "aaa",
  "lastName": "aaa",
  "email": "[email protected]",
  "role": 1,
  "profileUrl": ""
},
"token": "eyJ0eXAiOiJKV1QiLCJhbGciOiJIUzI1NiJ9.eyJ1c2VyIjp7ImZpcnN0TmFtZSI6ImFhYSIsImxhc3ROYW1lIjoiYWFhIiwiZW1haWwiOiJ4eHhAZ21haWwuY29tIiwicm9sZSI6MSwicHJvZmlsZVVybCI6IiJ9LCJpYXQiOjE0ODY1MjMyOTAsImV4cCI6MTQ4NjUzNDczMH0.kFHji61mqqupMSNBL_ZLnaLbK1xmFxbD6MbWa_SPlyo",
"enum": {
  "_id": "5889d3f10893a7a42243998e",
  "updatedAt": "2017-01-26T10:48:17.233Z",
  "createdAt": "2017-01-26T10:48:17.233Z",
  "__v": 0,
  "mailCategories": [
    {
      "color": [
        "Work",
        "Document",
        "Social",
        "Advertising",
        "Client"
      ],
      "value": [
        "#1ab394",
        "#EF5352",
        "#1c84c6",
        "#23c6c8",
        "#F8AC59"
      ]
    }
  ],
  "folders": [
    "Send",
    "Draft"
  ],
  "uploadsImageTypes": [
    "jpg",
    "jpeg",
    "png",
    "gif"
  ],
  "uploadsFileTypes": [
    "jpg",
    "jpeg",
    "docx",
    "pdf",
    "txt",
    "ppt",
    "png",
    "gif"
  ],
  "workOrderStatus": {
    "color": [
      "#A09580",
      "#f8ac59",
      "#41b0f6",
      "#0d71b0",
      "#1ab394",
      "#067e47",
      "#2819bc",
      "#0d08f3",
      "#ef0c34",
      "#ef9aa9",
      "#f2830b"
    ],
    "value": [
      "Draft",
      "Requested",
      "Requested Awaiting Approval",
      "Assigned",
      "Work In Progress",
      "Ready",
      "Done",
      "Closed,Completed",
      "Closed,Incompleted",
      "On Hold",
      "Open"
    ]
  },
  "priorities": {
    "color": [
      "#0B7409",
      "#CE9B9B",
      "#7CC396",
      "#CEBE99"
    ],
    "value": [
      "Hard Down",
      "High",
      "Medium",
      "Low"
    ]
  },
  "categories": [
    "Equipment",
    "Cranes",
    "Delivery Vehicles",
    "Rotating Spares"
  ],
  "projects": [
    "Vehicle New",
    "System #7865",
    "Book Shop",
    "Site"
  ],
  "maintenanceTypes": {
    "color": "#FFFFFF",
    "bg_color": [
      "#1c84c6",
      "#262626",
      "#A09580",
      "#ed5565"
    ],
    "value": [
      "Electrical",
      "Damage",
      "Safty",
      "Broken"
    ]
  },
  "assets": [
    "Conveyor Belt 1",
    "Cranes",
    "Delivery Vehicles",
    "Rotating Spares"
  ],
  "assignToUser": [
    1,
    2,
    4,
    5,
    6
  ],
  "roles": [
    "Admin",
    "Manager",
    "Technician",
    "Customer",
    "Supplier",
    "Engineer",
    "Guest"
  ]
}
}
}
{
"success": true,
"message": {
"user": {
  "fi