com.googlecode.classgenerator.ProxyFactory.scala Maven / Gradle / Ivy

Go to download

Show more of this group Show more artifacts with this name
Show all versions of classgenerator Show documentation

classgenerator is a scala library that wraps javassist and provides various patterns for generating classes via subclassing and implementing interfaces.

There is a newer version: 0.7.0-2.11

Show newest version

package com.googlecode.classgenerator

import javassist.util.proxy.Proxy
import javassist.util.proxy.MethodHandler
import java.lang.reflect.Method
import java.lang.reflect.Constructor
import javassist.util.proxy.MethodFilter

/**
 * @author kostantinos.kougios
 *
 * 8 Apr 2012
 */
class ProxyFactory[T] protected[classgenerator] (
		handled: Handled,
		interfaces: Array[Class[_]],
		invokeF: (Object, Method, Method, Array[Object]) => Object,
		clz: Class[T]) {

	private val pf = new javassist.util.proxy.ProxyFactory
	if (!interfaces.isEmpty) pf.setInterfaces(interfaces)
	pf.setSuperclass(clz)
	pf.setFilter(new MethodFilter {
		def isHandled(m: Method) = handled(m)
	})

	val proxyClass = pf.createClass.asInstanceOf[Class[T]]

	def constructor(args: Class[_]*) =
		proxyClass.getConstructor(args: _*)

	def newInstance(constructor: Constructor[T], params: Array[Any]) = {
		val n = constructor.newInstance(params.asInstanceOf[Array[Object]]: _*)
		init(n)
		n
	}
	def newInstance = {
		val n = proxyClass.newInstance
		init(n)
		n
	}

	private val methodHandler = new MethodHandler {
		override def invoke(self: Object, m: Method, proceed: Method, args: Array[Object]): Object =
			invokeF(self, m, proceed, args).asInstanceOf[Object]
	}
	private def init(t: T) {
		val proxy = t.asInstanceOf[Proxy]
		proxy.setHandler(methodHandler)
	}
}