使用java将相同日期的JSON数据分组在一起
我使用java创建了一个json对象,其值如下所示使用java将相同日期的JSON数据分组在一起,java,json,Java,Json,我使用java创建了一个json对象,其值如下所示 { "result":[ {"ID":7252,"Age":52,"Date":"2015-11-25","DAY":"Wednesday","Gender":"M"}, {"ID":7252,"Age":52,"Date":"2015-12-05","DAY":"Saturday","Gender":"M"}, .... ], "status":"ok" } 我需要根据日期对数据进行分组,所需格式如下所示
{
"result":[
{"ID":7252,"Age":52,"Date":"2015-11-25","DAY":"Wednesday","Gender":"M"},
{"ID":7252,"Age":52,"Date":"2015-12-05","DAY":"Saturday","Gender":"M"},
....
],
"status":"ok"
}
我需要根据日期对数据进行分组,所需格式如下所示
{
"result":[
{"2015-11-25":[
{"ID":7252,"Age":52,"Date":"2015-11-25","DAY":"Wednesday","Gender":"F"},
{"ID":7252,"Age":52,"Date":"2015-11-25","DAY":"Wednesday","Gender":"M"}
]},
{"2015-10-25":[
{"ID":7252,"Age":52,"Date":"2015-10-25","DAY":"Tuesday","Gender":"F"},
{"ID":7252,"Age":52,"Date":"2015-10-25","DAY":"Tuesday","Gender":"M"}
]},
],
"status":"ok"
}
基本上,我需要将所有相同的日期数据分组到JSON中
以日期为键
如何使用java实现这种JSON格式?您使用哪种JSON映射器?杰克逊,格森 请提供一些代码。让我们看看你在做什么 如果您使用Java创建JSON对象,那么您应该具有Java对象结构,对吗 大概是这样的:
class Data {
int id;
int age;
LocalDate date;
...
}
还有一个数组/数据列表:
List<Data> result = new ArrayList<>();
result.add(data1);
result.add(data2);
result.add(data3);
Map<LocalDate, Data> grouped = result
.stream()
.collect(
Collectors.groupingBy(Data::getDate)
);
然后,您可以使用Java8 Stream API对数据进行分组:
List<Data> result = new ArrayList<>();
result.add(data1);
result.add(data2);
result.add(data3);
Map<LocalDate, Data> grouped = result
.stream()
.collect(
Collectors.groupingBy(Data::getDate)
);
结果将是一张地图。你的结果应该是一个列表
因此,您应该能够简单地迭代映射并将其插入到新列表中