RMI 2019-03-18

步骤:
1.自定义 创建 java interface 类 并且继承 Remote (接口类命名随意)

    public interface RMethod extends Remote {
      String sayHello() throws RemoteException;
    }

2. 创建实现类 RMethodImpl 实现自定义接口类里面的抽象方法 并且继承 UnicastRemoteObject

    public class RMethodImpl extends UnicastRemoteObject implements RMethod {
      private static final long serialVersionUID = 1L;
   
      protected RMethodImpl() throws RemoteException {
          super();
      }
   
       @Override
      public String sayHello() throws RemoteException {
          return "I am test.";
      }
   }
   

   注意:
   private static final long serialVersionUID = 1L 必须加
   构造函数也必须加 super();也加上

3. 服务端测试代码

    public class Server {
      static int PORT = 9999;// 端口
      static String SERVER_IP = "172.16.0.89";// IP地址
      static String OBJECT_NAME = "test";// 绑定名字
   
      public static void main(String[] args) {
          try {
              System.setProperty("java.rmi.server.hostname", "172.16.0.89");// 绑定自己的IP
              LocateRegistry.createRegistry(PORT);
              RMethod rm = new RMethodImpl();
              String objAddr = "rmi://" + SERVER_IP + ":" + PORT + "/" + OBJECT_NAME;
              Context context = new InitialContext();
              context.rebind(objAddr, rm);
              System.out.println("Server is running...");
          } catch (Exception e) {
              System.out.println("Server startup failed!");
              e.printStackTrace();
          }
      }
    }
   

4.客户端测试代码

public class C {
    public static void main(String[] args) {
        RMethod rMethod;
        try {
            rMethod = (RMethod)Naming.lookup("//172.16.0.74:9999/test");
            System.out.println(rMethod.sayHello());
        } catch (MalformedURLException e) {
            e.printStackTrace();
        } catch (RemoteException e) {
            e.printStackTrace();
        } catch (NotBoundException e) {
            e.printStackTrace();
        }
    }
}

5.注意事项
- 测试端接口类的位置(类全名得一样)
- 安全组件问题 (先别加安全组件了 把RMI玩起来再说)
System.setSecurityManager(new SecurityManager());
rmi.policy