Java分布式之RMI简介及实例

1、Java分布式之RMI简介及实例前言最近的联通项目,下一阶段可能会涉及到和各省间的RMI接口,所以总结一下08年中国移动自动拨测系统用到的RMI技术,以备不时之需。同时也给广大初哥提供一些学习资料,哈哈。前几年,一直忙于项目,没怎么做系统总结。以后计划写一些以前项目用过的Java分布式技术实例教程,如:RMI、Socket、Mina、SNMP、SOAP、Web Service、Hessian、JMS等。希望和大家一起交流,分享经验,一起提高。RMI简介RMI,远程方法调用(Remote Method Invocation是Enterprise JavaBeans的支柱,是建立分布式Java应用

2、程序的方便途径。RMI是非常容易使用的,但是它非常的强大。RMI的基础是接口,RMI构架基于一个重要的原理:定义接口和定义接口的具体实现是分开的。看看jboss-remoting:基本原理要实现网络机器间的通讯,首先得来看看计算机系统网络通信的基本原理,在底层层面去看,网络通信需要做的就是将流从一台计算机传输到另外一台计算机,基于传输协议和网络IO来实现,其中传输协议比较出名的有http、tcp、udp等等,http、tcp、udp都是在基于Socket概念上为某类应用场景而扩展出的传输协议,网络IO,主要有bio、nio、aio三种方式,所有的分布式应用通讯都基于这个原理而实现,只是为了应用

3、的易用,各种语言通常都会提供一些更为贴近应用易用的应用层协议。主要步骤分为以下几个步骤:1. 创建远程接口及声明远程方法(RmiMonitorService.java2. 实现远程接口及远程方法(继承UnicastRemoteObject(RmiMonitorServiceImpl.java3. 启动RMI注册服务,并注册远程对象(RmiServer.java4. 客户端查找远程对象,并调用远程方法(MonitorClient.java5. 运行实例业务场景在移动拨测系统管理端中要融合实时显示。简单点说就是设备出现告警时,要采用不同方式实时展示。如Web界面(Ajax、GIS等。主要业务流程设

4、计:1. 设备告警2. 调用RMI Client3. 调用RMI Server4. 调用业务处理接口5. 告警信息入库6. 实时显示(Ajax,Gis等技术技术设计接口函数函数名称:int interactive( int funindex, string param 参数说明:funindex 功能号,整型。1为设备告警param 交互参数,字符串型。返回:成功=1,失败=0。说明:param交互参数用键值对组成,每个键值对以“&”分割,如: Tsid=01&devid=002&warnid=102&warntype=01&warnlevel=1 。测

5、试点ID(tsid设备ID(devid告警ID(warnid告警类型(warntype告警级别(warnlevel代码实现废话少说,上代码,为了演示方便,经过整理,省去了很多get,set之类的东东还有业务的东西以及Spring相关的东西。Java代码RmiMonitorService.java/* Description: 实时显示RMI服务接口.* author Peter Wei* version 1.0 Feb 25, 2009*/public interface RmiMonitorService extends Remote /* 实时显示对外接口* param funindex*

6、 功能号* param param* 键名列表,也就是实际传输的内容* return* throws RemoteException*/public int interactive(int funindex, String param throws RemoteException; RmiMonitorServiceImpl.java/* Description: 实时显示RMI接口实现.* 实现RMI接口及远程方法(继承UnicastRemoteObject* author Peter Wei* version 1.0 Feb 25, 2009*/public class RmiMonito

7、rServiceImpl extends UnicastRemoteObject implements RmiMonitorService public static final int SUCCSS = 1;public static final int FAIL = 0;public WarnService warnService;/* 必须定义构造方法,因为要抛出RemoteException异常* throws RemoteException*/public RmiMonitorServiceImpl( throws RemoteException super(;public int

8、interactive(int funindex, String param throws RemoteException int result = FAIL;switch (funindex / 告警case (1: / warnService = (WarnService AppContext.getAppContext(.getBean(/ "warn.warnService"/ 实际应用是从Spring应用中获取告警Service,如上代码warnService = new WarnServiceImpl(;/ 网络告警的业务操作warnService.dealWa

9、rn(param;result = SUCCSS;break;case (2:/ do other bizbreak;/ .return result;public WarnService getWarnService( return warnService;public void setWarnService(WarnService warnService this.warnService = warnService;RmiServer.java/* Description: RMI服务端.* author Peter Wei* version 1.0 Feb 25, 2009*/publi

10、c class RmiServer public String ip = "localhost"public int port = 8889;/* 启动RMI注册服务,并注册远程对象.实际应用中是在Spring初始化并启动*/public void init( try LocateRegistry.createRegistry(port;/ 创建一个远程对象RmiMonitorService comm = new RmiMonitorServiceImpl(;Naming.bind("/" + ip + ":" + port + &q

11、uot;/comm", comm; catch (RemoteException e e.printStackTrace(; catch (AlreadyBoundException e e.printStackTrace(; catch (MalformedURLException e e.printStackTrace(;public String getIp( return ip;public void setIp(String ip this.ip = ip;public int getPort( return port;public void setPort(int por

12、t this.port = port;public static void main(String args / 实际应用中是在Spring初始化并启动RmiServer rmiServer = new RmiServer(;rmiServer.init(;MonitorClient.java/* Description: RMI客户端.* author Peter Wei* version 1.0 Feb 25, 2009*/public class MonitorClient public RmiMonitorService monitorService;public String ip

13、= "localhost"public int port = 8889;public int interactive(int funindex, String param int result = 0;try getMonitorService(.interactive(funindex, param;result = 1; catch (RemoteException e e.printStackTrace(;return result;public RmiMonitorService getMonitorService( try / 在RMI服务注册表中查找名称为Rmi

14、MonitorService的对象,并调用其上的方法monitorService = (RmiMonitorService Naming.lookup("rmi:/" + ip+ ":" + port + "/comm" catch (NotBoundException e e.printStackTrace(; catch (MalformedURLException e e.printStackTrace(; catch (RemoteException e e.printStackTrace(;return monitorSer

15、vice;public static void main(String args throws RemoteException MonitorClient client = new MonitorClient(;String msg = "tsid=1022&devid=10001027&warnid=102&warntype=01&warnlevel=1&warnmsg=设备出错,请检查."eractive(1, msg;public String getValue(String content, String

16、key String value = ""int begin = 0, end = 0;begin = content.indexOf(key + "="end = content.indexOf("&", begin;if (end = -1end = content.length(;value = content.substring(begin + key.length( + 1, end;return value;WarnService.java/* Description: 告警服务* author Peter Wei

17、* version 1.0 2010-8-22*/public interface WarnService /* 处理告警:告警来时的业务操作,实际操作是解析消息存库,然后界面Ajax定时刷新数据,获取实时告警展示* param message* return*/public int dealWarn(String message;WarnServiceImpl.java/* Description: 告警服务* author Peter Wei* version 1.0 2010-8-22*/public class WarnServiceImpl implements WarnServic

18、e public int dealWarn(String message / 告警处理方法/ return 1;RmiMonitorService.java/* Description: 实时显示RMI服务接口.* author Peter Wei* version 1.0 Feb 25, 2009*/public interface RmiMonitorService extends Remote /* 实时显示对外接口* param funindex* 功能号* param param* 键名列表,也就是实际传输的内容* return* throws RemoteException*/pu

19、blic int interactive(int funindex, String param throws RemoteException; RmiMonitorServiceImpl.java/* Description: 实时显示RMI接口实现.* 实现RMI接口及远程方法(继承UnicastRemoteObject* author Peter Wei* version 1.0 Feb 25, 2009*/public class RmiMonitorServiceImpl extends UnicastRemoteObject implements RmiMonitorService

20、public static final int SUCCSS = 1;public static final int FAIL = 0;public WarnService warnService;/* 必须定义构造方法,因为要抛出RemoteException异常* throws RemoteException*/public RmiMonitorServiceImpl( throws RemoteException super(;public int interactive(int funindex, String param throws RemoteException int resu

21、lt = FAIL;switch (funindex / 告警case (1: / warnService = (WarnService AppContext.getAppContext(.getBean(/ "warn.warnService"/ 实际应用是从Spring应用中获取告警Service,如上代码warnService = new WarnServiceImpl(;/ 网络告警的业务操作warnService.dealWarn(param;result = SUCCSS;break;case (2:/ do other bizbreak;/ .return r

22、esult;public WarnService getWarnService( return warnService;public void setWarnService(WarnService warnService this.warnService = warnService;RmiServer.java/* Description: RMI服务端.* author Peter Wei* version 1.0 Feb 25, 2009*/public class RmiServer public String ip = "localhost"public int p

23、ort = 8889;/* 启动RMI注册服务,并注册远程对象.实际应用中是在Spring初始化并启动*/public void init( try LocateRegistry.createRegistry(port;/ 创建一个远程对象RmiMonitorService comm = new RmiMonitorServiceImpl(;Naming.bind("/" + ip + ":" + port + "/comm", comm; catch (RemoteException e e.printStackTrace(; ca

24、tch (AlreadyBoundException e e.printStackTrace(; catch (MalformedURLException e e.printStackTrace(;public String getIp( return ip;public void setIp(String ip this.ip = ip;public int getPort( return port;public void setPort(int port this.port = port;public static void main(String args / 实际应用中是在Spring

25、初始化并启动RmiServer rmiServer = new RmiServer(;rmiServer.init(;MonitorClient.java/* Description: RMI客户端.* author Peter Wei* version 1.0 Feb 25, 2009*/public class MonitorClient public RmiMonitorService monitorService;public String ip = "localhost"public int port = 8889;public int interactive(i

26、nt funindex, String param int result = 0;try getMonitorService(.interactive(funindex, param;result = 1; catch (RemoteException e e.printStackTrace(;return result;public RmiMonitorService getMonitorService( try / 在RMI服务注册表中查找名称为RmiMonitorService的对象,并调用其上的方法monitorService = (RmiMonitorService Naming.l

27、ookup("rmi:/" + ip+ ":" + port + "/comm" catch (NotBoundException e e.printStackTrace(; catch (MalformedURLException e e.printStackTrace(; catch (RemoteException e e.printStackTrace(;return monitorService;public static void main(String args throws RemoteException MonitorClient client = new M