Description

An interface to the Java(tm) VM

Author

Daishi Kato and felix

Version

• 0.1 Initial release

Usage

(require-extension jni)

Download

jni.egg

Documentation

This extension uses the Java(tm) native interface (JNI) to run a Java(tm) from Scheme code.

To build this extension you should set some environment variables before invoking chicken-setup:

• for GCJ, set CHICKEN_JNI_USE_GCJ to some non-empty value
• for Linux, set JNI_H_PATH and JNI_LIB_PATH to the directories where jni.h and libvjm are situated

macro: (define-java-classes NAME ...)

Defines the variables NAME ..., holding pointers to the Java classes of the same name. NAME may be either a symbol or a list of the form (VARIABLE CLASSNAME).

(define-java-classes Foo Bar) is equivalent to (begin (define Foo (jni:find-class "Foo")) (define Bar (jni:find-class "Bar")))

The following JNI procedures are provided:

(jni:find-class STRING) -> CLASS
(jni:define-class STRING LOADER BYTE-VECTOR LENGTH) -> CLASS
(jni:get-version) -> INT
(jni:get-superclass CLASS) -> SUPERCLASS
(jni:is-assignable-from? CLASS SUPERCLASS) -> BOOL
(jni:throw THROWABLE) -> INT
(jni:throw-new CLASS STRING) -> INT
(jni:exception-occurred) -> THROWABLE
(jni:exception-describe)
(jni:exception-clear)
(jni:fatal-error STRING)
(jni:is-same-object? OBJECT1 OBJECT2) -> BOOL
(jni:get-object-class OBJECT) -> CLASS
(jni:is-instance-of? OBJECT CLASS) -> BOOL
(jni:exception-check) -> BOOL
(jni:monitor-enter OBJECT) -> INT
(jni:monitor-exit OBJECT) -> INT
(jni:get-array-length OBJECT) -> INT
(jni:new-object-array LENGTH CLASS OBJECT) -> OBJECT'
(jni:get-object-array-element OBJECT' INT) -> OBJECT
(jni:set-object-array-element! OBJECT' INT OBJECT) 
(jni:string->jstring STRING) -> OBJECT
(jni:jstring->string OBJECT) -> STRING

Arguments named OBJECT, CLASS and THROWABLE should be Java objects.

procedure: (jni:object? X)

Returns #t if X is a Java object or #f otherwise.

procedure: (jni:method RETURN-TYPE CLASS NAME TYPELIST [SAFE?])

Returns a procedure that, when called, will invoke the Java method NAME (which should be a string or symbol) and that has the result-type RETURN-TYPE and the argument-types given in TYPELIST. CLASS should be a Java object representing a class. If SAFE? is given and true, then the method may invoke callbacks into Scheme.

The returned procedure takes the receiver object as its first argument, followed by zero or more method arguments.

procedure: (jni:nonvirtual-method RETURN-TYPE CLASS NAME TYPELIST [SAFE?])

Similar to jni:method but returns a procedure that will call a method looked up in a specific class.

procedure: (jni:static-method RETURN-TYPE CLASS NAME TYPELIST [SAFE?])

Similar to jni:method but returns a procedure that will call a static method. The procedure does not take an additional argument beyond the arguments that are expected by the static method.

procedure: (jni:constructor CLASS TYPELIST [SAFE?])

Similar to jni:method but returns a procedure that will call a constructor method.

procedure: (jni:field CLASS TYPE NAME)

Returns a procedure that can be used to access the field NAME (a string or symbol). The accessor-procedure accepts a single argument: the instance from which the field value should be retrieved. The returned procedure has a setter, so to modify the field, execute (set! (<ACCESSOR> <OBJECT>) <VALUE>).

procedure: (jni:static-field CLASS TYPE NAME)

Returns a procedure that can be used to access the static field NAME (a string or symbol). The accessor-procedure takes zero arguments. The returned procedure has a setter, so to modify the field, execute (set! (<ACCESSOR>) <VALUE>).

License

Copyright (c) 2005, Daishi Kato and Felix Winkelmann.  All rights reserved.

Permission is hereby granted, free of charge, to any person obtaining a
copy of this software and associated documentation files (the Software),
to deal in the Software without restriction, including without limitation
the rights to use, copy, modify, merge, publish, distribute, sublicense,
and/or sell copies of the Software, and to permit persons to whom the
Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included
in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED ASIS, WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
OTHER DEALINGS IN THE SOFTWARE.