Clojure 调用(.write socket data)时出现空指针异常
我正在编写一个简单的IRC bot来尝试了解更多关于Clojure的信息,使用标准Java套接字和循环来读取/解析数据,但是由于某种原因,当我尝试在MOTD end消息之后发送JOIN消息时,我得到了一个空指针 这是我的密码Clojure 调用(.write socket data)时出现空指针异常,clojure,nullpointerexception,irc,Clojure,Nullpointerexception,Irc,我正在编写一个简单的IRC bot来尝试了解更多关于Clojure的信息,使用标准Java套接字和循环来读取/解析数据,但是由于某种原因,当我尝试在MOTD end消息之后发送JOIN消息时,我得到了一个空指针 这是我的密码 (use 'clojure.java.io '[clojure.string :as s :only (split)]) (def sock (java.net.Socket. "iris.archivesmc.com" 6667)) (def write-stream
(use 'clojure.java.io
'[clojure.string :as s :only (split)])
(def sock (java.net.Socket. "iris.archivesmc.com" 6667))
(def write-stream (writer sock))
(def read-stream (reader sock))
(defn write [message]
(.write write-stream (str message "\r\n"))
(println (str "-> " message))
(.flush write-stream)
)
(defn parseMessage [buffer]
(if
(= (apply str (take-last 2 buffer)) "\r\n" )
(do
(let [parts (split buffer #"\s")]
(println (s/replace buffer "\r\n" ""))
(when
(= (first parts) "PING")
;; We need to PONG to this or we'll ping out
(write (str "PONG " (second parts)))
)
(when
(= (apply str(take 1 (first parts))) ":" )
;; Message with a numerical prefix
;; :server numeric our-nick message
(
(if
(= (second parts) "376")
;; MOTD end
;; Join #clojure
(write "JOIN #clojure") ;; This errors for some reason
)
)
)
)
""
)
buffer
)
)
(defn readLoop []
(loop [buffer ""]
;;(println (str "Looping.. -> " buffer))
(let [nbuf (parseMessage buffer)
nchr (.read read-stream) ]
(if-not (= nchr -1)
(recur (str nbuf (char nchr)))
)
)
)
)
(write "NICK gClojureTestBot")
(write "USER Clojure Imma Bot :Clojure Testing Bot")
(readLoop)
这是我的输出(带有回溯等)
我觉得这很奇怪,因为以前对write
的调用都能正常工作。再说一次,作为一个Clojure(和Java)noob,我可能做了一些愚蠢的事情
有人有什么想法吗
编辑:如果有问题,我使用的是Java 7和Clojure 1.4.0,问题在于下面的代码块
(when
(= (apply str(take 1 (first parts))) ":" )
;; Message with a numerical prefix
;; :server numeric our-nick message
(
(if
(= (second parts) "376")
;; MOTD end
;; Join #clojure
(write "JOIN #clojure") ;; This errors for some reason
)
)
)
具体地说,围绕
(if)
语句的()
被加倍。括号太多。删除多余的代码修复了问题。问题在于以下代码块
(when
(= (apply str(take 1 (first parts))) ":" )
;; Message with a numerical prefix
;; :server numeric our-nick message
(
(if
(= (second parts) "376")
;; MOTD end
;; Join #clojure
(write "JOIN #clojure") ;; This errors for some reason
)
)
)
具体地说,围绕
(if)
语句的()
被加倍。括号太多。删除多余的括号修复了问题。通过遵循括号的标准lisp约定,您可以使意外执行此操作更加困难。如果没有帕伦人在自己的线路上,几乎不可能意外地写((foo-bar))而不是(foo-bar),如果你这样做了,它会非常明显并且很容易修复。@amalloy我喜欢你关于定位帕伦人的回答,并且被告知在最后跟踪他们。@amalloy Smart thinking那里;我会记住的。谢谢。通过遵循括号的标准lisp约定,您可以使意外执行此操作变得更加困难。如果没有帕伦人在自己的线路上,几乎不可能意外地写((foo-bar))而不是(foo-bar),如果你这样做了,它会非常明显并且很容易修复。@amalloy我喜欢你关于定位帕伦人的回答,并且被告知在最后跟踪他们。@amalloy Smart thinking那里;我会记住的。谢谢