Gson名称数组，并包含一个新属性

Question

我开始使用json，需要一些帮助来解决这个问题。

我有一个POJO

public class HiReceiptsObj{ 
     private string warehouse_id; 
     private String owner_id; 
private String receipt; 

.....// all with Getters and setters 

} 

我调用Java方法，其中我加载收据的ArrayList像这样

List<HiReceiptsObj> receipts = new ArrayList<HiReceiptsObj>(); 

，然后我用GSON到ArrayList转换为JSON

String receiptsJson = new Gson().toJson(receipts); 
      response.setContentType("application/json"); 
      response.setCharacterEncoding("UTF-8"); 
      response.getWriter().write(receiptsJson); 

This will output

[{"warehouse_id":"US01","owner_id":"NP ","receipt":"INV"}, 
{"warehouse_id":"US01","owner_id":"NP ","receipt":"082212-3047 "}, 
{"warehouse_id":"US01","owner_id":"NP ","receipt":"INVADJUST"}] 

我需要这种输出的

{ 
    "total_pages": 10, 
    "rows": [ 
    {"warehouse_id":"US01","owner_id":"NP ","receipt":"INV"}, 
    {"warehouse_id":"US01","owner_id":"NP ","receipt":"082212-3047 "}, 
    {"warehouse_id":"US01","owner_id":"NP ","receipt":"INVADJUST"} 
    ] 

} 

我已阅读有关本的其他职位，但他们对我来说太先进了，可有人请帮助？

感谢

Answer 1

1）你也应该有你的目的一个holder类：

public class ReceiptHolder { 
    @SerializedName("total_pages") 
    private int totalPages; 

    private List<HiReceiptsObj> rows; 

    // TODO: add getter/setters 
} 

2）创建receiptHolder实例并填写：

List<HiReceiptsObj> receipts = new ArrayList<HiReceiptsObj>(); 
ReceiptHolder receiptHolder = new ReceiptHolder(); 
receiptHolder.setRows(receipts); 
receiptHolder.setTotalPages(receipts.size()); 

3）序列化receiptHolder：

String receiptsJson = new Gson().toJson(receiptHolder); 

输出为你想要的东西：

{ 
    "total_pages": 10, 
    "rows": [ 
    { 
     "warehouse_id": "US01", 
     "owner_id": "NP ", 
     "receipt": "INV" 
    }, 
    { 
     "warehouse_id": "US01", 
     "owner_id": "NP ", 
     "receipt": "082212-3047 " 
    }, 
    { 
     "warehouse_id": "US01", 
     "owner_id": "NP ", 
     "receipt": "INVADJUST" 
    } 
    ] 
}