从封装的json中获取价值

I've the following JSON file:

我有以下JSON文件:

[

{
    "AVG_VALUE" : "2540", 
    "MAX_VALUE" : "2540",
    "SUM_VALUE" : "2540",
    "MIN_VALUE" : "2540",
    "METRICID" : "100248060212",
    "START" : "1449216120000",
    "STARTTIME" : "09:02"
}
,
{
    "AVG_VALUE" : "2624", 
    "MAX_VALUE" : "2708",
    "SUM_VALUE" : "5248",
    "MIN_VALUE" : "2540",
    "METRICID" : "100248060219",
    "START" : "1449216120000",
    "STARTTIME" : "09:02"
}
]
[