要在JRuby中实现java接口，接口
include进来，实现接口方法即可，例如实现java.lang.Runnable接口做线程处理：
require 'java' include_class 'java.lang.Runnable' class
TestRunnable include Runnable
def
initialize(name) @name
=
name end
def
run puts
"
hello,
"
+
@name end end
要在JRuby中继承抽象类，实现其中的抽象方法，方法稍微麻烦点，需要cglib，到
这里下载cglib-nodep-2.1_3.jar，写个通用库abstract_class.rb方便处理:
load
'
cglib-nodep-2.1_3.jar
'
class
Object include Java include_class
"
net.sf.cglib.proxy.Enhancer
"
include_class
"
net.sf.cglib.proxy.NoOp
"
class
<<
self
def
method_missing(mname,
*
args,
&
block) unless mname
==
:abstract_impl
and
respond_to?(:java_class)
and
JavaLang::reflect::Modifier.isAbstract(JavaLang::Class.for_name(java_class.name).modifiers) super
else
generate_abstract_impl(args,
&
block) end end private
def
generate_abstract_impl(args,
&
block) factory
=
Enhancer.new factory.setSuperclass(java_class) factory.setInterfaces(java_class.interfaces.to_java(
"
java.lang.Class
"
)) factory.setCallback(NoOp::INSTANCE) object_args
=
args.map {
|
arg
|
Java.ruby_to_java(arg) } class_arguments
=
object_args.map {
|
arg
|
arg.java_class}.to_java(
"
java.lang.Class
"
) generated_class
=
factory.create(class_arguments, object_args.to_java(
"
java.lang.Object
"
)) ruby_class
=
Class.new(generated_class.
class
) ruby_class.class_eval(
&
block)
return
ruby_class.new(
*
args) end end end
使用的话，require一下abstract_class，例如我们要继承java.util.TimerTask，实现其中的run方法：
$:.unshift File.join(File.dirname(
__FILE__
),
'
.
'
) require
'
java
'
require
'
abstract_class
'
import
java.util.TimerTask
import
java.util.Timer timer_task
=
TimerTask.abstract_impl do
def
run puts
"
timer task
"
end end Timer.new.schedule(timer_task,
1000
,
1000
)
文章转自庄周梦蝶 ，原文发布时间2008-02-15
相关资源：敏捷开发V1.0.pptx
