Bean Scripting Framework.

曾俊雄

What is Scripting Language

Broader definition: all languages

Narrower definition: those programming languages requiring

no compilation or with implicit compilation

For example: JavaScript

source: http://zh.wikipedia.org/wiki/JavaScript

Why Scripting Languages?

simplicity real time most scripting languages have good UI

integration plenty of choices

Where to Use Scripting Languages?

integrated with UI languages, e.x., html vs. JavaScript

event-based scenarios, e.x., XSLT vs. xpath

programming with less ability but more simplicity, e.x., JSP

Drawbacks

Performance!!

Java + Scripting Language

Background Java performs better, but more complicat

ed in syntax and requires compilation Scripting languages (e.x., JavaScript) are

much slower (almost 1000x), but much easier in syntax and requires no compilation

Java + Scripting language is a good compromise use java in major part use scripting language for some

customizable parts but how?

JVM

byte code

script

Scripting Engine

load scripting engine with JVM, and pass scripting parts into the scripting engine.

However, different scripting engines have different interfaces……

Bean Scripting Framework

Actually, there is a plan to add common scripting interface into JVM with JavaSE 7.0 but when can we have JavaSE 7.0 ?!

Now, we have apache bean scripting framework http://jakarta.apache.org/bsf/

BSFManager

BSFEngine

JRubyEngine JavaScriptEngine PythonEngine ……

Usage

Register script engine to BSFManager BSFManager.registerScriptingEngine("ruby", "org.jruby.javasupp

ort.bsf.JRubyEngine", new String[]{"rb"});

Create an instance of BSFManager BSFManager manager=new BSFManager();

Load registered script engine from the manager engine=manager.loadScriptingEngine("ruby");

Execute the scripting code, so it is kept in the memory engine.exec("ruby", 0, 0, “……script code……”);

Call target method declared in the scripting code engine.call(null, "actionPerformed", new java.lang.Object[]{self, arg0});

This is Ruby!!

Why use Ruby?

Simple yet powerful exactly the same expressive power with j

ava good bridging with jvm

http://jruby.codehaus.org/

Language Constructs

require 'java'

module Java include_package "java.lang" include_package "javax.swing" include_package "util.ws" include_package "java.util"end

def actionPerformed(caller, actionEvent) if actionEvent.getActionCommand()=="HelloWorld" Java::JOptionPane.showMessageDialog(caller, "HelloWorld") elsif actionEvent.getActionCommand()=="HelloWS" response=Java::WebServiceClient.send("http://localhost:8084/SpringWSTest/services", "<sayHello xmlns=\"HelloWorld\"/>") Java::JOptionPane.showMessageDialog(caller, response) elsif actionEvent.getActionCommand()=="HelloSoapHeaders" props=Java::HashMap.new props.put("{ns1}key1","value1") props.put("{ns2}key2",['_value1','_value2','_value3'].to_java) response=Java::WebServiceClient.send("http://localhost:8084/SpringWSTest/services", "<sayHello xmlns=\"HelloWorld\"/>", props) Java::JOptionPane.showMessageDialog(caller, response) endend

load java supportimport java.lang.*;

import javax.swing.*;

import util.ws.*;

import java.util.*; define function

require 'java'

module Java include_package "java.lang" include_package "javax.swing" include_package "util.ws" include_package "java.util"end

def actionPerformed(caller, actionEvent) if actionEvent.getActionCommand()=="HelloWorld" Java::JOptionPane.showMessageDialog(caller, "HelloWorld") elsif actionEvent.getActionCommand()=="HelloWS" response=Java::WebServiceClient.send("http://localhost:8084/SpringWSTest/services", "<sayHello xmlns=\"HelloWorld\"/>") Java::JOptionPane.showMessageDialog(caller, response) elsif actionEvent.getActionCommand()=="HelloSoapHeaders" props=Java::HashMap.new props.put("{ns1}key1","value1") props.put("{ns2}key2",['_value1','_value2','_value3'].to_java) response=Java::WebServiceClient.send("http://localhost:8084/SpringWSTest/services", "<sayHello xmlns=\"HelloWorld\"/>", props) Java::JOptionPane.showMessageDialog(caller, response) endend

load java supportimport java.lang.*;

import javax.swing.*;

import util.ws.*;

import java.util.*; define function