(defmacro defun-class-method (lfun cls-name meth-name &rest arg-types)

  (let ((arglist (mapcar (lambda (x) (gensym)) arg-types))

(method (gensym))

(cls (gensym)))

    `(let ((,method (jmethod ,cls-name ,meth-name ,@arg-types))

   (,cls (jclass ,cls-name)))

       (defun ,lfun ,arglist

 (jcall ,method ,cls ,@arglist)))))

(defmacro defun-instance-method (lfun cls-name meth-name &rest arg-types)

  (let ((arglist (mapcar (lambda (x) (gensym)) (cons nil arg-types)))

(method (gensym)))

    `(let ((,method (jmethod ,cls-name ,meth-name ,@arg-types)))

       (defun ,lfun ,arglist

 (jcall ,method ,@arglist)))))

(defmacro defun-constructor (lfun cls-name &rest arg-types)

  (let ((arglist (mapcar (lambda (x) (gensym)) arg-types))

(method (gensym)))

    `(let ((,method (jconstructor ,cls-name ,@arg-types)))

       (defun ,lfun ,arglist

 (jnew ,method ,@arglist)))))

Examples:

The following line defines a lisp function named "java-abs".  java-abs is a proxy for the java version.  It takes the same arguments.  

(defun-class-method java-abs "java.lang.Math" "abs" "int")

After the above is called, you may call the Java method from lisp as follows:

(java-abs -44)

The lisp functions created by these utilities are fast because they are closures.  The class and method lookups are only done once.

Other examples: