json - 如何将文件中的 json 条目转换为数据框？

Question

我正在尝试读取包含 json 内容的文件并根据某些字段将其转换为表格数据。

该文件包含如下内容:

{"senderDateTimeStamp":"2016/04/08 10:03:18","senderHost":null,"senderCode":"web_app","senderUsecase":"appinternalstats_prod","destinationTopic":"web_app_appinternalstats_realtimedata_topic","correlatedRecord":false,"needCorrelationCacheCleanup":false,"needCorrelation":false,"correlationAttributes":null,"correlationRecordCount":0,"correlateTimeWindowInMills":0,"lastCorrelationRecord":false,"realtimeESStorage":true,"receiverDateTimeStamp":1460124283554,"payloadData":{"timestamp":"2016-04-08T10:03:18.244","status":"get","source":"MSG1","ITEM":"TEST1","basis":"","pricingdate":"","content":"","msgname":"","idlreqno":"","host":"web01","Webservermember":"Web"},"payloadDataText":"","key":"web_app:appinternalstats_prod","destinationTopicName":"web_app_appinternalstats_realtimedata_topic","esindex":"web_app","estype":"appinternalstats_prod","useCase":"appinternalstats_prod","Code":"web_app"}

我需要能够将时间戳、源、主机、状态字段以及每行的 payloadData 部分转换为 R 中的数据帧。

我已经试过了:

库(rjson)d<-fromJSON(file="file.txt")

dput(d)
structure(list(senderDateTimeStamp = "2016/04/08 10:03:18", senderHost = NULL, 
                  senderAppcode = "web", senderUsecase = "appinternalstats_prod", 
                  destinationTopic = "web_appinternalstats_realtimedata_topic", 
                  correlatedRecord = FALSE, needCorrelationCacheCleanup = FALSE, 
                  needCorrelation = FALSE, correlationAttributes = NULL, correlationRecordCount = 0, 
                  correlateTimeWindowInMills = 0, lastCorrelationRecord = FALSE, 
                  realtimeESStorage = TRUE, receiverDateTimeStamp = 1460124283554, 
                  payloadData = structure(list(timestamp = "2016-04-08T10:03:18.244", 
                                               status = "get", source = "MSG1", 
                                               region = "", evetid = "", osareqid = "", basis = "", 
                                               pricingdate = "", content = "", msgname = "", recipient = "", 
                                               objid = "", idlreqno = "", host = "web01", webservermember = "webSingleton"), 
                                          .Names = c("timestamp", 
                                           "status", "source", "region", "evetid", 
                                          "osareqid", "basis", "pricingdate", "content", "msgname", 
                                          "recipient", "objid", "idlreqno", "host", "webservermember"
                                               )), payloadDataText = "", key = "web:appinternalstats_prod", 
                  destinationTopicName = "web_appinternalstats_realtimedata_topic", 
                  hdfsPath = "web/appinternalstats_prod", esindex = "web", 
                  estype = "appinternalstats_prod", useCase = "appinternalstats_prod", 
                  appCode = "web"), .Names = c("senderDateTimeStamp", "senderHost", 
                                               "senderAppcode", "senderUsecase", "destinationTopic", "correlatedRecord", 
                                               "needCorrelationCacheCleanup", "needCorrelation", "correlationAttributes", 
                                               "correlationRecordCount", "correlateTimeWindowInMills", "lastCorrelationRecord", 
                                               "realtimeESStorage", "receiverDateTimeStamp", "payloadData", 
                                               "payloadDataText", "key", "destinationTopicName", "hdfsPath", 
                                               "esindex", "estype", "useCase", "appCode"))

关于如何将 json 条目的 payloadData 部分转换为数据帧的任何想法？

Answer 1

这可能是您想要的:

library(rjson)
d<-fromJSON(file="file.txt")
myDf <- do.call("rbind", lapply(d, function(x) { 
               data.frame(TimeStamp = x$payloadData$timestamp, 
                          Source = x$payloadData$source, 
                          Host = $payloadData$host, 
                          Status = x$payloadData$status)}))