配置 clojure 日志记录以输出到 nRepl

Question

我正在寻找一种方法来配置 clojure.tools.logging 以将消息输出到 nRepl。我只找到一些配置输出到console。

Answer 1

默认情况下，控制台输出打印在 *nrepl-server* 缓冲区。因此，如果您将 clojure.tools.logging 配置为将输出打印到控制台，那么您可以在 *nrepl-server* 缓冲区中看到它。

我在 CIDER 文档中找不到更改此设置的方法。但我发现discussion 与这个问题有关。有提议这样一个solution：

;; run this code on the repl where you wish to see all output.
;; You will need to add the dependency [commons-io "2.4"] to your
;; leiningen dependencies.
(import 'org.apache.commons.io.output.WriterOutputStream)
(import 'java.io.PrintStream)

;; First, we redirect the raw stdout of the server to this repl
(System/setOut (PrintStream. (WriterOutputStream. *out*)
                             true)) ;; Auto-flush the PrintStream

;; Next, we alter the root binding of *out* so that new threads
;; send their output to THIS repl rather than the original System/out.
(alter-var-root #'*out* (fn [_] *out*))

;; Now the snippets should both send output to this repl:
(.println System/out "Hello stdout.")
(.start (Thread. #(println "Hello from a new thread.")))

但在我的安装（CIDER 0.12.0，Clojure 1.8.0）上它抱怨(.start (Thread. #(println "Hello from a new thread.")))：

error in process filter: [nREPL] No response handler with id nil found

但是，如果我不运行(alter-var-root #'*out* (fn [_] *out*))，那么下面的打印示例效果很好，并将其输出打印到 *cider-repl* 中而不会出现错误或警告。记录器输出也打印到 *cider-repl*。