curl :: curl_fetch_memory(url,handle = handle)出错：从对等端接收数据失败

我正在尝试从 chartlyrics API获取歌词.我编写了一个可以工作但不在循环内的R函数.我的脚本是：

library(httr)
library(RCurl)
library(XML)

df <- data.frame(artist = c('Led Zeppellin','Adele'),song = c('Rock´n roll','Hello'),stringsAsFactors = F)

make.querye <- function(xx) {
  names_ok <- gsub(" ","&",xx)
  names_ok2 <- paste("\'",names_ok,"\'",sep = '')
 querye <- paste("http://api.chartlyrics.com/apiv1.asmx/SearchLyricDirect?artist=",names_ok[1],"&song=",names_ok[2],sep='')
 data <- GET(querye)
 aa <- content(data,"text")   
 doc <- htmlParse(aa,asText=TRUE)  
 plain.text <- xpathSApply(doc,"//lyric//text()[not(ancestor::script)][not(ancestor::style)][not(ancestor::noscript)][not(ancestor::form)]",xmlValue)  
 if (length(plain.text)==0) {
   plain.text2 <- 'Lyrics not found'
 } else {
   plain.text2 <- iconv(plain.text,from = "UTF-8",to = "latin1",sub = NA,mark = TRUE,toRaw = FALSE)  
 }
 return(plain.text2)
 }


names <- c(df$artist[1],df$song[1])
make.querye(names) #- it works

names <- c(df$artist[2],df$song[2])
make.querye(names) #- it also works

但是我的函数在循环中不起作用

for (ii in  1:2){
  names <- c(df$artist[ii],df$song[ii])
  print(names)
  make.querye(names)
}

我收到以下错误：

Error in curl::curl_fetch_memory(url,handle = handle) : Failure when receiving data from the peer

解决方法

RETRY功能是在 June 2016中引入的,允许您多次重试请求,直到成功为止.

将它与参数verb =“GET”一起使用,而不是直接使用GET,即

data <- RETRY("GET",query)

您还可以使用times参数定义最大尝试次数.