在下面的测试中，我需要创建一个临时文件并添加一些内容，调用main方法，然后查看是否生成了正确的输出。
我可以看到在“ / tmp”中创建的文件，但它始终为空。就像BufferedWriter不在写它。我在做什么错了？
library(lubridate)
library(rvest)
oldurl <- "https://waterdata.usgs.gov/ca/nwis/uv/?site_no=11401920&PARAmeter_cd=00065,00060"
flow = html_text(html_node(read_html(oldurl),".stationContainer:nth-child(5)")) #Selector ID'd by https://selectorgadget.com/
stage = html_text(html_node(read_html(oldurl),".stationContainer:nth-child(6)")) #Selector ID'd by https://selectorgadget.com/
flow <- gsub("(T).*","\\1", flow)
flow <- gsub("Most recent instantaneous value:","", flow)
flow <- gsub("\n","", flow)
flow <- gsub("Discharge, cubic feet per second","cfs", flow)
flow <- gsub("(?<=[\\s])\\s*|^\\s+|\\s+$", "", flow, perl=TRUE)
flow <- strsplit(flow, " ")
flow <- unlist(flow)
unit <- flow[1]
value <- flow[2]
date <- paste0(flow[3]," ", flow[4], " ", flow[5])
flow <- data.frame(value, unit, date) %>% mutate(value =
as.character(value), value = as.integer(value), date = mdy_hm(date))
as_tibble(flow)
#<int> <fct> <dttm>
#363 cfs 2019-05-06 07:30:00
stage <-gsub("(T).*","\\1", stage)
stage <-gsub("Most recent instantaneous value:","", stage)
stage <-gsub("\n","", stage)
stage <-gsub("Gage height, feet ","ft", stage)
stage <- gsub("(?<=[\\s])\\s*|^\\s+|\\s+$", "", stage, perl=TRUE)
stage <- strsplit(stage, " ")
stage <- unlist(stage)
unit <- stage[1]
value <- stage[2]
date <- paste0(stage[3]," ", stage[4], " ", stage[5])
stage <- data.frame(value, unit, date) %>% mutate(value =
as.character(value), value = as.double(value), date =
mdy_hm(date))
as_tibble(stage)
# <dbl> <fct> <dttm>
# 6.32 ft 2019-05-06 07:30:00
## how to get the same, flow and stage, from their new page?
newurl <- "https://waterdata.usgs.gov/monitoring-location/11401920/"