rmi remote server on spring framework by annotation

rmi คือ การ remote service ข้ามเครื่องวิธีหนึ่ง ส่วนใหญ่จะใช้ในกรณีแยก service ออกจาก interface เพื่อ

1. ความปลอดภัย คือ ทำให้สามารถควบคุมการเข้าถึง การเรียกใช้ และการดึงข้อมูลที่สำคัญ หรือเป็นความลับ
รวมถึงการกำหนดข้อจำกัดต่าง ๆ

2. การทำเป็น service กลาง ซึ่งทำให้ไม่ต้องเขียน service ขึ้นมาใหม่บ่อย ๆ ในรูปแบบงานที่คล้าย ๆ กันเกิดขึ้นใหม่
และเป็นการแยก interface ทำให้สามารถ แก้ไข หรือ เปลีี่ยนแปลง interface ได้ตลอดเวลาโดยไม่กระทบ

ที่เหลือคิดไม่ออก แล้ว ไว้ว่าง ๆ มาเขียนข้อดีเพิ่มให้ครับ ^^'

ตัวอย่างโดยใช้ xml ทำการ config บน spring framework
http://static.springsource.org/spring/docs/2.0.4/reference/remoting.html

บทความถัดไป
rmi remote client on spring framework by annotation

เรามาเปลี่ยนจาก xml เป็น annotation กัน เริ่มจาก
project/WebContent/WEB-INF/web.xml

    MUWAHOBack
    
        contextConfigLocationclasspath:conf/applicationContext.xml
    
        org.springframework.web.context.ContextLoaderListener
    
    
        org.springframework.web.context.request.RequestContextListener
    
    
        30
    
    
        index.jsp
    

มาถึง config service file
project\src\conf\applicationContext.xml

    <context:annotation-config/>
    <context:component-scan base-package="com.company.project.service" />
    <import resource="/rmiContext.xml" />

อันนี้แยกในส่วน rmi ออกมาเป็น
project\src\conf\rmiContext.xml

มาถึงส่วนสำคัญในการประกาศ service rmi
ส่วนแรกจะเป็น Application Context ที่ประกาศเป็นตัวเริ่มต้น เพื่อให้ reuse ได้
project\src\com\company\spring\context\ApplicationContextProvider.java

package com.company.spring.context;

import org.springframework.beans.BeansException;
import org.springframework.beans.factory.DisposableBean;
import org.springframework.beans.factory.config.BeanFactoryPostProcessor;
import org.springframework.beans.factory.config.BeanPostProcessor;
import org.springframework.context.ApplicationContext;
import org.springframework.context.ApplicationContextAware;

public abstract class ApplicationContextProvider implements
  ApplicationContextAware, BeanFactoryPostProcessor, BeanPostProcessor,
  DisposableBean {

 private ApplicationContext context;

 public ApplicationContext getContext() {
  return context;
 }

 @Override
 public void setApplicationContext(ApplicationContext context)
   throws BeansException {
  this.context = context;
 }
}

ต่อมาเป็นในส่วนที่ทำเพื่อประกาศ Annotation เราจะนำ Annotation ตัวนี้ไปแปะไว้
บน Class implement ที่เราต้องการประกาศให้เป็น service rmi
project\src\com\company\spring\remoting\RmiServer.java

package com.company.spring.remoting;

import java.lang.annotation.Documented;
import java.lang.annotation.ElementType;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.Target;

import org.springframework.stereotype.Component;

@Target( { ElementType.TYPE })
@Retention(RetentionPolicy.RUNTIME)
@Documented
@Component
public @interface RmiServer {
 
 String name() default "";
 
 Class<?> serviceInterface();
}

ส่วนต่อไป ทำการผูก service ที่ประกาศ Annotation @RmiServer เพื่อประกาศ
service ให้ใช้บริการ rmi ได้โดยผูกเข้ากับ Bean factory ของ Spring
project\src\com\company\spring\remoting\RemoteAnnotationBeanFactoryPostProcessor.java

package com.company.spring.remoting;

import java.rmi.registry.Registry;
import java.util.ArrayList;
import java.util.List;
import org.springframework.aop.framework.Advised;
import org.springframework.beans.BeansException;
import org.springframework.beans.FatalBeanException;
import org.springframework.beans.factory.config.BeanDefinition;
import org.springframework.beans.factory.config.ConfigurableListableBeanFactory;
import org.springframework.core.annotation.AnnotationUtils;
import org.springframework.remoting.rmi.RmiServiceExporter;
import org.springframework.remoting.support.RemoteExporter;
import com.company.spring.context.ApplicationContextProvider;

public class RemoteAnnotationBeanFactoryPostProcessor extends
  ApplicationContextProvider {

 private String basePackage;

 private List<String> remoteExporterNames = new ArrayList<String>();

 @Override
 public Object postProcessBeforeInitialization(Object obj, String beanName)
   throws BeansException {
  System.out
    .println(" RemoteAnnotationBeanFactoryPostProcessor >> postProcessBeforeInitialization ");
  System.out.println(" >> Bean name : " + beanName);
  System.out.println(" >> Class name : " + obj);
  return obj;
 }

 @Override
 public void postProcessBeanFactory(
   ConfigurableListableBeanFactory beanFactory) throws BeansException {
  System.out
    .println(" RemoteAnnotationBeanFactoryPostProcessor >> postProcessBeanFactory ");

  for (String beanName : beanFactory.getBeanDefinitionNames()) {

   System.out.println(" BeanDefinitionNames : " + beanName);

   BeanDefinition beanDefinition = beanFactory
     .getBeanDefinition(beanName);

   // Ignore abstract bean! and empty beans
   if (beanDefinition.isAbstract()
     || beanDefinition.getBeanClassName() == null
     || beanDefinition.getBeanClassName().indexOf(basePackage) == -1) {
    continue;
   }

   try {
    RmiServer remote = AnnotationUtils.findAnnotation(Class
      .forName(beanDefinition.getBeanClassName()),
      RmiServer.class);

    if (remote == null) {
     continue;
    }

    String remoteExporterName = getRmiServiceBeanName(remote);
    System.out.println(" Register Singleton RemoteExporterName : "
      + remoteExporterName);
    RemoteExporter remoteExporter = createRemoteExporter(remote);

    beanFactory.registerSingleton(remoteExporterName,
      remoteExporter);

    remoteExporterNames.add(remoteExporterName);
   } catch (ClassNotFoundException e) {
    throw new FatalBeanException("No class for name " + beanName, e);
   }
  }
 }

 private String getRmiServiceBeanName(RmiServer remote) {
  return "/" + remote.serviceInterface().getSimpleName();
 }

 private RemoteExporter createRemoteExporter(RmiServer remote) {
  RmiServiceExporter remoteExporter = new RmiServiceExporter();

  remoteExporter.setServiceInterface(remote.serviceInterface());
  remoteExporter
    .setServiceName(remote.serviceInterface().getSimpleName());

  return remoteExporter;
 }

 @Override
 public Object postProcessAfterInitialization(Object obj, String beanName)
   throws BeansException {
  System.out
    .println(" RemoteAnnotationBeanFactoryPostProcessor >> postProcessAfterInitialization ");
  System.out.println(" >> Bean name : " + beanName);
  System.out.println(" >> Class name : " + obj);
  Class<?> targetClass = null;
  Object _obj = obj;

  while (_obj instanceof Advised) {
   Advised advised = (Advised) _obj;
   try {
    _obj = advised.getTargetSource().getTarget();
   } catch (Exception e) {
    throw new FatalBeanException(
      "Exception initializing RmiServiceExporter", e);
   }
  }

  targetClass = _obj.getClass();

  RmiServer remote = AnnotationUtils.findAnnotation(targetClass,
    RmiServer.class);

  if (remote == null) {
   return obj;
  }
  try {

   RmiServiceExporter remoteExporter = (RmiServiceExporter) getContext()
     .getBean(getRmiServiceBeanName(remote));
   remoteExporter.setService(obj);

   Registry registry = getContext().getBean("rmiRegistry",
     Registry.class);
   remoteExporter.setRegistry(registry);
   remoteExporter.afterPropertiesSet();

   System.out.println("Create remote service success " + "with name "
     + remote.serviceInterface().getSimpleName()
     + " with RMI registry: " + registry + ".");
  } catch (Exception e) {
   throw new FatalBeanException(
     "Exception initializing RmiServiceExporter", e);
  }

  return obj;
 }

 @Override
 public void destroy() throws Exception {
  System.out
    .println(" RemoteAnnotationBeanFactoryPostProcessor >> destroy ");
  for (String remoteExporterName : remoteExporterNames) {
   getContext().getBean(remoteExporterName, RmiServiceExporter.class)
     .destroy();
  }
 }

 /*
  * auto-create get-set method.
  */
 public String getBasePackage() {
  return basePackage;
 }

 public void setBasePackage(String basePackage) {
  this.basePackage = basePackage;
 }

 public List<String> getRemoteExporterNames() {
  return remoteExporterNames;
 }

 public void setRemoteExporterNames(List<String> remoteExporterNames) {
  this.remoteExporterNames = remoteExporterNames;
 }
}

========================================
ส่วนต่อไปคือเริ่มทำ service ที่ใช้งานจริงๆ กันเลยดีกว่าเริ่มด้วย
Interface service
project\src\com\company\project\service\ItestService.java

package com.company.project.service;

public interface ItestService {
 public String getPrefixHello(String str);
}

project\src\com\company\project\service\TestService.java
Implements service

package com.company.project.service;

import org.springframework.stereotype.Service;
import com.company.spring.remoting.RmiServer;

@RmiServer(serviceInterface = ItestService.class)
@Service
public class TestService implements ItestService {

 @Override
 public String getPrefixHello(String str) {
  System.out.println(" TestService >> getPrefixHello ");
  return "Hello 123 : "+str;
 }

}

หลังจากนั้นก็ลอง test service ดูโดยทำตัว test ขึ้นมา
project\src\com\company\project\test\TestServiceTest.java

package com.company.project.test;

import org.junit.After;
import org.junit.Before;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.test.context.ContextConfiguration;
import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;

import com.company.project.service.ItestService;

@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration(locations={"classpath:/conf/applicationContext.xml"})
public class TestServiceTest {
 
 @Autowired
 private ItestService itestService;
 
 public void setItestService(ItestService itestService) {
  this.itestService = itestService;
 }

 @Before
 public void setUp() throws Exception {
  System.out.println("setUp");
 }

 @After
 public void tearDown() throws Exception {
  System.out.println("tearDown");
 }
 
 @Test
 public void testGetData() {
  System.out.println("testGetData");
  String outStr = "";
  try{
   outStr = this.itestService.getPrefixHello("test 123 d^^");
   System.out.println("result : " + outStr);
  }catch(Exception e){
   System.out.println("ERROR : " + e);
   e.printStackTrace();
  }
 }
}

log ที่ได้หลังจาก run test

12 พ.ค. 2553 11:06:38 org.springframework.test.context.TestContextManager retrieveTestExecutionListeners
INFO: @TestExecutionListeners is not present for class [class com.company.project.test.TestServiceTest]: using defaults.
12 พ.ค. 2553 11:06:38 org.springframework.beans.factory.xml.XmlBeanDefinitionReader loadBeanDefinitions
INFO: Loading XML bean definitions from class path resource [conf/applicationContext.xml]
12 พ.ค. 2553 11:06:39 org.springframework.beans.factory.xml.XmlBeanDefinitionReader loadBeanDefinitions
INFO: Loading XML bean definitions from class path resource [conf/rmiContext.xml]
12 พ.ค. 2553 11:06:39 org.springframework.context.support.AbstractApplicationContext prepareRefresh
INFO: Refreshing org.springframework.context.support.GenericApplicationContext@7ffe01: startup date [Wed May 12 11:06:39 ICT 2010]; root of context hierarchy
12 พ.ค. 2553 11:06:39 org.springframework.remoting.rmi.RmiRegistryFactoryBean getRegistry
INFO: Looking for RMI registry at port '1019'
12 พ.ค. 2553 11:06:40 org.springframework.remoting.rmi.RmiRegistryFactoryBean getRegistry
INFO: Could not detect RMI registry - creating new one
RemoteAnnotationBeanFactoryPostProcessor >> postProcessBeanFactory
BeanDefinitionNames : org.springframework.context.annotation.internalConfigurationAnnotationProcessor
BeanDefinitionNames : org.springframework.context.annotation.internalAutowiredAnnotationProcessor
BeanDefinitionNames : org.springframework.context.annotation.internalRequiredAnnotationProcessor
BeanDefinitionNames : org.springframework.context.annotation.internalCommonAnnotationProcessor
BeanDefinitionNames : testService
Register Singleton RemoteExporterName : /ItestService
BeanDefinitionNames : rmiRegistry
BeanDefinitionNames : appContextProvider
BeanDefinitionNames : com.company.spring.remoting.RemoteAnnotationBeanFactoryPostProcessor#0
12 พ.ค. 2553 11:06:40 org.springframework.beans.factory.support.DefaultListableBeanFactory preInstantiateSingletons
INFO: Pre-instantiating singletons in org.springframework.beans.factory.support.DefaultListableBeanFactory@ff057f: defining beans [org.springframework.context.annotation.internalConfigurationAnnotationProcessor,org.springframework.context.annotation.internalAutowiredAnnotationProcessor,org.springframework.context.annotation.internalRequiredAnnotationProcessor,org.springframework.context.annotation.internalCommonAnnotationProcessor,testService,rmiRegistry,appContextProvider,com.company.spring.remoting.RemoteAnnotationBeanFactoryPostProcessor#0]; root of factory hierarchy
RemoteAnnotationBeanFactoryPostProcessor >> postProcessBeforeInitialization
>> Bean name : testService
>> Class name : com.company.project.service.TestService@15a6029
RemoteAnnotationBeanFactoryPostProcessor >> postProcessAfterInitialization
>> Bean name : testService
>> Class name : com.company.project.service.TestService@15a6029
12 พ.ค. 2553 11:06:40 org.springframework.remoting.rmi.RmiServiceExporter prepare
INFO: Binding service 'ItestService' to RMI registry: RegistryImpl[UnicastServerRef [liveRef: [endpoint:[10.239.20.141:1019](local),objID:[0:0:0, 0]]]]
Create remote service success with name ItestService with RMI registry: RegistryImpl[UnicastServerRef [liveRef: [endpoint:[10.239.20.141:1019](local),objID:[0:0:0, 0]]]].
RemoteAnnotationBeanFactoryPostProcessor >> postProcessBeforeInitialization
>> Bean name : com.company.project.test.TestServiceTest
>> Class name : com.company.project.test.TestServiceTest@f9c40
RemoteAnnotationBeanFactoryPostProcessor >> postProcessAfterInitialization
>> Bean name : com.company.project.test.TestServiceTest
>> Class name : com.company.project.test.TestServiceTest@f9c40
setUp
testGetData
TestService >> getPrefixHello
result : Hello 123 : test 123 d^^
tearDown
12 พ.ค. 2553 11:06:40 org.springframework.context.support.AbstractApplicationContext doClose
INFO: Closing org.springframework.context.support.GenericApplicationContext@7ffe01: startup date [Wed May 12 11:06:39 ICT 2010]; root of context hierarchy
12 พ.ค. 2553 11:06:40 org.springframework.beans.factory.support.DefaultSingletonBeanRegistry destroySingletons
INFO: Destroying singletons in org.springframework.beans.factory.support.DefaultListableBeanFactory@ff057f: defining beans [org.springframework.context.annotation.internalConfigurationAnnotationProcessor,org.springframework.context.annotation.internalAutowiredAnnotationProcessor,org.springframework.context.annotation.internalRequiredAnnotationProcessor,org.springframework.context.annotation.internalCommonAnnotationProcessor,testService,rmiRegistry,appContextProvider,com.company.spring.remoting.RemoteAnnotationBeanFactoryPostProcessor#0]; root of factory hierarchy
12 พ.ค. 2553 11:06:40 org.springframework.remoting.rmi.RmiServiceExporter destroy
INFO: Unbinding RMI service 'ItestService' from registry at port '1099'
12 พ.ค. 2553 11:06:40 org.springframework.remoting.rmi.RmiRegistryFactoryBean destroy
INFO: Unexporting RMI registry
RemoteAnnotationBeanFactoryPostProcessor >> destroy

ลอง run บน env server tomcat6

12 พ.ค. 2553 11:06:01 org.apache.tomcat.util.digester.SetPropertiesRule begin
WARNING: [SetPropertiesRule]{Server/Service/Engine/Host/Context} Setting property 'source' to 'org.eclipse.jst.jee.server:TestRmiAnnoServer' did not find a matching property.
12 พ.ค. 2553 11:06:01 org.apache.catalina.core.AprLifecycleListener init
INFO: The APR based Apache Tomcat Native library which allows optimal performance in production environments was not found on the java.library.path: C:\Program Files\Java\jre6\bin;.;C:\WINDOWS\Sun\Java\bin;C:\WINDOWS\system32;C:\WINDOWS;C:/Program Files/Java/jre6/bin/client;C:/Program Files/Java/jre6/bin;C:\Program Files\CA\SC\CAWIN\;C:\WINDOWS\system32;C:\WINDOWS;C:\WINDOWS\system32\wbem;.;C:\Program Files\Java\jdk1.6.0_11\bin;C:\Program Files\Common Files\NetSarang;C:\Program Files\Java\jdk1.6.0_11\BIN;C:\ant\bin;C:\Oracle9i\bin;C:\Program Files\Oracle\jre\1.3.1\bin;C:\Program Files\Oracle\jre\1.1.8\bin;C:\Ora6i\bin;C:\ORANT\bin;C:\TUXEDO\bin;C:\Program Files\SQLLIB\BIN;C:\Program Files\SQLLIB\HELP;C:\Ora6i\jdk\bin;C:\ORAWIN\Bin;C:\Program Files\cvsnt;;C:\Program Files\Common Files\Compuware;C:\PROGRA~1\CA\SC\CAM\bin;C:\Program Files\CA\DSM\bin;C:\ORAWIN\BIN;C:\ORANT\BIN;C:\CUBICS3T;C:\TUXEDO\BIN;
12 พ.ค. 2553 11:06:01 org.apache.coyote.http11.Http11Protocol init
INFO: Initializing Coyote HTTP/1.1 on http-8080
12 พ.ค. 2553 11:06:01 org.apache.catalina.startup.Catalina load
INFO: Initialization processed in 801 ms
12 พ.ค. 2553 11:06:01 org.apache.catalina.core.StandardService start
INFO: Starting service Catalina
12 พ.ค. 2553 11:06:01 org.apache.catalina.core.StandardEngine start
INFO: Starting Servlet Engine: Apache Tomcat/6.0.18
12 พ.ค. 2553 11:06:02 org.apache.catalina.core.ApplicationContext log
INFO: Initializing Spring root WebApplicationContext
12 พ.ค. 2553 11:06:02 org.springframework.web.context.ContextLoader initWebApplicationContext
INFO: Root WebApplicationContext: initialization started
12 พ.ค. 2553 11:06:02 org.springframework.context.support.AbstractApplicationContext prepareRefresh
INFO: Refreshing Root WebApplicationContext: startup date [Wed May 12 11:06:02 ICT 2010]; root of context hierarchy
12 พ.ค. 2553 11:06:03 org.springframework.beans.factory.xml.XmlBeanDefinitionReader loadBeanDefinitions
INFO: Loading XML bean definitions from class path resource [conf/applicationContext.xml]
12 พ.ค. 2553 11:06:03 org.springframework.beans.factory.xml.XmlBeanDefinitionReader loadBeanDefinitions
INFO: Loading XML bean definitions from class path resource [conf/rmiContext.xml]
12 พ.ค. 2553 11:06:04 org.springframework.remoting.rmi.RmiRegistryFactoryBean getRegistry
INFO: Looking for RMI registry at port '1019'
12 พ.ค. 2553 11:06:05 org.springframework.remoting.rmi.RmiRegistryFactoryBean getRegistry
INFO: Could not detect RMI registry - creating new one
RemoteAnnotationBeanFactoryPostProcessor >> postProcessBeanFactory
BeanDefinitionNames : org.springframework.context.annotation.internalConfigurationAnnotationProcessor
BeanDefinitionNames : org.springframework.context.annotation.internalAutowiredAnnotationProcessor
BeanDefinitionNames : org.springframework.context.annotation.internalRequiredAnnotationProcessor
BeanDefinitionNames : org.springframework.context.annotation.internalCommonAnnotationProcessor
BeanDefinitionNames : testService
Register Singleton RemoteExporterName : /ItestService
BeanDefinitionNames : rmiRegistry
BeanDefinitionNames : appContextProvider
BeanDefinitionNames : com.company.spring.remoting.RemoteAnnotationBeanFactoryPostProcessor#0
12 พ.ค. 2553 11:06:05 org.springframework.beans.factory.support.DefaultListableBeanFactory preInstantiateSingletons
INFO: Pre-instantiating singletons in org.springframework.beans.factory.support.DefaultListableBeanFactory@1e1dadb: defining beans [org.springframework.context.annotation.internalConfigurationAnnotationProcessor,org.springframework.context.annotation.internalAutowiredAnnotationProcessor,org.springframework.context.annotation.internalRequiredAnnotationProcessor,org.springframework.context.annotation.internalCommonAnnotationProcessor,testService,rmiRegistry,appContextProvider,com.company.spring.remoting.RemoteAnnotationBeanFactoryPostProcessor#0]; root of factory hierarchy
RemoteAnnotationBeanFactoryPostProcessor >> postProcessBeforeInitialization
>> Bean name : testService
>> Class name : com.company.project.service.TestService@1777b1
RemoteAnnotationBeanFactoryPostProcessor >> postProcessAfterInitialization
>> Bean name : testService
>> Class name : com.company.project.service.TestService@1777b1
12 พ.ค. 2553 11:06:05 org.springframework.remoting.rmi.RmiServiceExporter prepare
INFO: Binding service 'ItestService' to RMI registry: RegistryImpl[UnicastServerRef [liveRef: [endpoint:[10.239.20.141:1019](local),objID:[0:0:0, 0]]]]
Create remote service success with name ItestService with RMI registry: RegistryImpl[UnicastServerRef [liveRef: [endpoint:[10.239.20.141:1019](local),objID:[0:0:0, 0]]]].
12 พ.ค. 2553 11:06:05 org.springframework.web.context.ContextLoader initWebApplicationContext
INFO: Root WebApplicationContext: initialization completed in 2516 ms
12 พ.ค. 2553 11:06:05 org.apache.coyote.http11.Http11Protocol start
INFO: Starting Coyote HTTP/1.1 on http-8080
12 พ.ค. 2553 11:06:05 org.apache.jk.common.ChannelSocket init
INFO: JK: ajp13 listening on /0.0.0.0:8009
12 พ.ค. 2553 11:06:05 org.apache.jk.server.JkMain start
INFO: Jk running ID=0 time=0/47 config=null
12 พ.ค. 2553 11:06:05 org.apache.catalina.startup.Catalina start
INFO: Server startup in 4107 ms