You might be better off using the httr
package.
library(httr)
library(XML)
url <- "http://www.cnj.jus.br/improbidade_adm/visualizar_condenacao.php"
for (i in 575:585){
response<- GET(url,path="/",query=c(seq_condenacao=as.character(i)))
if (response$status_code!=200){ # HTTP request failed!!
# do some stuff...
print(paste("Failure:",i,"Status:",response$status_code))
next
}
doc <- htmlParse(response, encoding = "UTF-8")
# do some other stuff
print(paste("Success:",i,"Status:",response$status_code))
}
# [1] "Success: 575 Status: 200"
# [1] "Success: 576 Status: 200"
# [1] "Success: 577 Status: 200"
# [1] "Success: 578 Status: 200"
# [1] "Success: 579 Status: 200"
# [1] "Success: 580 Status: 200"
# [1] "Success: 581 Status: 200"
# [1] "Success: 582 Status: 200"
# [1] "Success: 583 Status: 200"
# [1] "Success: 584 Status: 200"
# [1] "Success: 585 Status: 200"