视频类网站开发,摄影图片网站,龙岗坪地网站建设公司,2345网址导航怎么彻底删掉1#xff09;RMI#xff08;remote method invocation#xff09;是java原生支持的远程调用#xff0c;RMI采用JRMP#xff08;java RemoteMessageing Protocol#xff09;作为通信协议。可以认为是纯java版本的分布式远程调用解决方法。 2#xff09;RMI的核心概念 3RMIremote method invocation是java原生支持的远程调用RMI采用JRMPjava RemoteMessageing Protocol作为通信协议。可以认为是纯java版本的分布式远程调用解决方法。 2RMI的核心概念 3RMI实现步骤 1、创建远程接口并继承java.rmi.Remote接口 2、实现远程接口并继承UnicastRemoteObject 3、创建服务器程序createRegistry() 方法注册远程对象 4、创建客户端程序获取注册信息调用接口方法 RMI_SERVER   package com.itheima.service;import java.rmi.Remote; import java.rmi.RemoteException;public interface UserService extends Remote {String sayHello(String name) throws RemoteException; } package com.itheima.service.impl;import com.itheima.service.UserService;import java.rmi.RemoteException; import java.rmi.server.UnicastRemoteObject;public class UserServiceImpl extends UnicastRemoteObject implements UserService {public UserServiceImpl() throws RemoteException {}Overridepublic String sayHello(String name) throws RemoteException {return name 调用了服务端的sayHello方法;} }package com.itheima.server;import com.itheima.service.UserService; import com.itheima.service.impl.UserServiceImpl;import java.net.MalformedURLException; import java.rmi.AlreadyBoundException; import java.rmi.Naming; import java.rmi.RemoteException; import java.rmi.registry.LocateRegistry;public class ServerMain {public static void main(String[] args) throws RemoteException, AlreadyBoundException, MalformedURLException {//启动RMI注册服务指定端口号LocateRegistry.createRegistry(8888);//创建要被访问的远程对象的实例UserService userService new UserServiceImpl();//将远程对象实例注册到RMI注册服务器上Naming.bind(rmi://127.0.0.1:8888/UserServer, userService);System.out.println(服务端启动中………………);} }RMI_CLIENT package com.itheima.service;import java.rmi.Remote; import java.rmi.RemoteException;public interface UserService extends Remote {String sayHello(String name) throws RemoteException; } package com.itheima.client;import com.itheima.service.UserService;import java.net.MalformedURLException; import java.rmi.Naming; import java.rmi.NotBoundException; import java.rmi.RemoteException;public class ClientMain {public static void main(String[] args) throws RemoteException, NotBoundException, MalformedURLException {UserService userService (UserService) Naming.lookup(rmi://127.0.0.1:8888/UserServer);String s userService.sayHello(客户端);System.out.println(s);} }注意 client中Naming.lookup需要强转成UserService  此时的package路径要与server中的Userserver中的路径一致 否则出现报错 C:\Program Files\Java\jdk1.8.0_131\bin\java.exe -javaagent:D:\ruanjian\ideaiu14\ideaiu14\idea\IntelliJ IDEA 2020.1\lib\idea_rt.jar63728:D:\ruanjian\ideaiu14\ideaiu14\idea\IntelliJ IDEA 2020.1\bin -Dfile.encodingUTF-8 -classpath C:\Program Files\Java\jdk1.8.0_131\jre\lib\charsets.jar;C:\Program Files\Java\jdk1.8.0_131\jre\lib\deploy.jar;C:\Program Files\Java\jdk1.8.0_131\jre\lib\ext\access-bridge-64.jar;C:\Program Files\Java\jdk1.8.0_131\jre\lib\ext\cldrdata.jar;C:\Program Files\Java\jdk1.8.0_131\jre\lib\ext\dnsns.jar;C:\Program Files\Java\jdk1.8.0_131\jre\lib\ext\jaccess.jar;C:\Program Files\Java\jdk1.8.0_131\jre\lib\ext\jfxrt.jar;C:\Program Files\Java\jdk1.8.0_131\jre\lib\ext\localedata.jar;C:\Program Files\Java\jdk1.8.0_131\jre\lib\ext\nashorn.jar;C:\Program Files\Java\jdk1.8.0_131\jre\lib\ext\sunec.jar;C:\Program Files\Java\jdk1.8.0_131\jre\lib\ext\sunjce_provider.jar;C:\Program Files\Java\jdk1.8.0_131\jre\lib\ext\sunmscapi.jar;C:\Program Files\Java\jdk1.8.0_131\jre\lib\ext\sunpkcs11.jar;C:\Program Files\Java\jdk1.8.0_131\jre\lib\ext\zipfs.jar;C:\Program Files\Java\jdk1.8.0_131\jre\lib\javaws.jar;C:\Program Files\Java\jdk1.8.0_131\jre\lib\jce.jar;C:\Program Files\Java\jdk1.8.0_131\jre\lib\jfr.jar;C:\Program Files\Java\jdk1.8.0_131\jre\lib\jfxswt.jar;C:\Program Files\Java\jdk1.8.0_131\jre\lib\jsse.jar;C:\Program Files\Java\jdk1.8.0_131\jre\lib\management-agent.jar;C:\Program Files\Java\jdk1.8.0_131\jre\lib\plugin.jar;C:\Program Files\Java\jdk1.8.0_131\jre\lib\resources.jar;C:\Program Files\Java\jdk1.8.0_131\jre\lib\rt.jar;F:\RPC\RMI\rmi_client\target\classes com.itheima.client.ClientMain Exception in thread main java.rmi.UnmarshalException: error unmarshalling return; nested exception is: java.lang.ClassNotFoundException: com.itheima.service.UserService (no security manager: RMI class loader disabled)at sun.rmi.registry.RegistryImpl_Stub.lookup(Unknown Source)at java.rmi.Naming.lookup(Naming.java:101)at com.itheima.client.ClientMain.main(ClientMain.java:12) Caused by: java.lang.ClassNotFoundException: com.itheima.service.UserService (no security manager: RMI class loader disabled)at sun.rmi.server.LoaderHandler.loadProxyClass(LoaderHandler.java:556)at java.rmi.server.RMIClassLoader$2.loadProxyClass(RMIClassLoader.java:646)at java.rmi.server.RMIClassLoader.loadProxyClass(RMIClassLoader.java:311)at sun.rmi.server.MarshalInputStream.resolveProxyClass(MarshalInputStream.java:265)at java.io.ObjectInputStream.readProxyDesc(ObjectInputStream.java:1758)at java.io.ObjectInputStream.readClassDesc(ObjectInputStream.java:1710)at java.io.ObjectInputStream.readOrdinaryObject(ObjectInputStream.java:2000)at java.io.ObjectInputStream.readObject0(ObjectInputStream.java:1535)at java.io.ObjectInputStream.readObject(ObjectInputStream.java:422)... 3 moreProcess finished with exit code 1运行结果 需要先启动服端 服务端启动中……………… 客户端结果 客户端调用了服务端的sayHello方法 说明在两个项目中客户端成功的调用了服务器的sayHello方法