如何在Java平台上使用脚本语言做Java开发(1)

String rubyScript = "def write(msg) \r\n" +
"      puts msg \r\n" +
"end \r\n" + 
"\r\n" +
" def anotherFunction() \r\n" +
"     # do something \r\n" +
"end \r\n";

ScriptEngineManager manager = new ScriptEngineManager();
ScriptEngine engine = manager.getEngineByName("jruby");

    engine.eval(rubyScript);
Invocable inv = (Invocable) engine;
inv.invokeFunction("write", new Object[] { "hello" });
// prints out:
// hello

from test import NonBlockingConnection
from java.lang import Integer
from java.lang import Long

class ExtendedNonBlockingConnection(NonBlockingConnection):
def write(self, *args):
# the signature to handle?
if len(args) == 1 and isinstance(args[0], Integer):
print 'writing overriden int ' + args[0].toString()
# no, let the super method do the stuff
else:
NonBlockingConnection.write(self, *args)

ExtendedNonBlockingConnection().write(Integer(777))
# prints out:
# writing overridden int 777

ExtendedNonBlockingConnection().write(Long(777))
# prints out:
# writing long 777

import test.NonBlockingConnection

class ExtendedNonBlockingConnection extends NonBlockingConnection {
// overwrite the int method
def write(int i) {
println 'writing overridden int ' + i
}
}

new ExtendedNonBlockingConnection().write((int) 777)
// prints out:
// writing overridden int 777

new ExtendedNonBlockingConnection().write((long) 777)
// prints out:
// writing long 777

include Java
RandomAccessFile = java.io.RandomAccessFile
DataConverter = Java::org.xsocket.DataConverter 
MultithreadedServer = Java::org.xsocket.stream.MultithreadedServer
IConnection = Java::org.xsocket.stream.IConnection
IConnectHandler = Java::org.xsocket.stream.IConnectHandler
IDataHandler = Java::org.xsocket.stream.IDataHandler

class TestMessageSinkManager
def new_message_sink_channel()
file = java.io.File.create_temp_file('smtptest', 'mail')
return RandomAccessFile.new(file, 'rw').channel
end
end
class SmtpProtocolHandler
include IConnectHandler
include IDataHandler
   def initialize(domain, message_sink_manager)
@domain = domain
@msg_sink_mgr = message_sink_manager
@helo_pattern = Regexp.compile(/HELO.*/, Regexp::IGNORECASE)
@mail_from_pattern = Regexp.compile(/MAIL FROM:.*/, Regexp::IGNORECASE)
@rcpt_to_pattern = Regexp.compile(/RCPT TO:.*/, Regexp::IGNORECASE)
@data_pattern = Regexp.compile(/DATA.*/, Regexp::IGNORECASE)
@quit_pattern = Regexp.compile(/QUIT.*/, Regexp::IGNORECASE)
end
# new incoming (non blocking) connection
def onConnect(nbc)
nbc.flushmode = IConnection::FlushMode::ASYNC
nbc.attachment = { 'state' => 'CMD', 'msg_num' => 0 }
nbc.write("220 #{@domain} SMTP ready \r\n")
return true
end
# data received for the (non blocking) connection
def onData(nbc)
case nbc.attachment['state']
# message receiving mode: non-blocking streaming of the msg data 
when 'MESSAGE'
# some validations have to be performed by the data sink
delimiter_found = nbc.read_available_by_delimiter("\r\n.\r\n", 
                nbc.attachment['message_channel'])          
if delimiter_found
nbc.attachment['message_channel'].close()
nbc.attachment['state'] = 'CMD'
nbc.write("250 OK #{nbc.get_id()}.#{nbc.attachment['msg_num']} \r\n")
end
         # smtp-command mode: perform command 
else
# a BufferUnderflowException will been thrown, if delimiter not found
smtp_cmd_line = nbc.read_string_by_delimiter("\r\n")
case smtp_cmd_line
when @helo_pattern
nbc.write("250 #{@domain} SMTP Service \r\n")
when @mail_from_pattern
originator = smtp_cmd_line[10,9999].strip()
# ...here some validations should be performed (valid address, ...) 
nbc.attachment['originator'] = originator
nbc.attachment['recipients'] = []
nbc.write("250 #{@originator} is syntactically correct\r\n")
               when @rcpt_to_pattern
rec = smtp_cmd_line[8,9999].strip()
# ...here some validations should be performed (max recipients, ...)
nbc.attachment['recipients'] = nbc.attachment['recipients'] << rec
nbc.write("250 #{rec} verified \r\n")  
               when @data_pattern
# ...here some validation should be performed (recipients set, ...)
nbc.attachment['state'] = 'MESSAGE'
nbc.attachment['msg_num'] = nbc.attachment['msg_num'] + 1
nbc.attachment['message_channel'] = 
                      @msg_sink_mgr.new_message_sink_channel()
time_stamp = "Received: FROM #{nbc.remote_address.canonical_host_name} 
                     BY #{@domain}\r\n" + 
"id #{nbc.get_id()}.#{nbc.attachment['msg_num']}; 
                     " + Time.new.to_s() + "\r\n"
nbc.attachment['message_channel'].write(DataConverter.to_byte_buffer(time_stamp,
    'US-ASCII'))                  
nbc.write("354 Enter message, ending with \".\"  \r\n")
               when @quit_pattern
nbc.write("221 SMTP service closing connection \r\n")
nbc.close()
               else 
nbc.write("500 Unrecognized command \r\n")
end         
end
return true
end
end
server = MultithreadedServer.new(25, SmtpProtocolHandler.new('mSrv', 
    TestMessageSinkManager.new))
server.run()