Clojure 被設計為一種寄宿語言，共用 JVM 類型系統、GC、執行緒等。它將所有函數編譯為 JVM 位元組碼。Clojure 是絕佳的 Java 函式庫使用者，提供點目標成員表示法來呼叫 Java。類別名稱可以在匯入後以完整名稱或非限定名稱來參照。Clojure 使用 reify 和 proxy 支援 Java 介面和類別的動態實作
輕易存取 Java 類別，就像這樣
(import '[java.time LocalDate])
(defn add-week ^LocalDate [^LocalDate date]
(.plusDays date 7))
(defn day->str [^LocalDate date]
(format "%s %s, %s" (.getMonth date) (.getDayOfMonth date) (.getYear date)))
;; infinite sequence of weekly dates, starting from today
(def future-weeks (iterate add-week (LocalDate/now)))
(map day->str (take 4 future-weeks))
;; ("JULY 24, 2017" "JULY 31, 2017" "AUGUST 7, 2017" "AUGUST 14, 2017")以下是較複雜的範例，一個小型 Swing 應用程式
(import '(javax.swing JFrame JLabel JTextField JButton)
'(java.awt.event ActionListener)
'(java.awt GridLayout))
(defn celsius []
(let [frame (JFrame. "Celsius Converter")
temp-text (JTextField.)
celsius-label (JLabel. "Celsius")
convert-button (JButton. "Convert")
fahrenheit-label (JLabel. "Fahrenheit")]
(.addActionListener
convert-button
(reify ActionListener
(actionPerformed
[_ evt]
(let [c (Double/parseDouble (.getText temp-text))]
(.setText fahrenheit-label
(str (+ 32 (* 1.8 c)) " Fahrenheit"))))))
(doto frame
(.setLayout (GridLayout. 2 2 3 3))
(.add temp-text)
(.add celsius-label)
(.add convert-button)
(.add fahrenheit-label)
(.setSize 300 80)
(.setVisible true))))
(celsius)