RMI协议的应用与研究

        最近公司需要将一个服务层框架进行升级，原来的RPC协议是用的RMI，由于RMI可能在不同版本的JVM之间传递会产生问题，因此需要找出一种RPC协议来替换掉EJB的RMI，要求有三个：一、在不同版本的JVM之间互调不会出现问题；二、支持引用参数传递；三、效率说得过去。于是就研究了几种RPC协议：RMI,hessian,spring集成的hessian以及基于kryo序列化机制的kryonet。首先研究RMI：
          1. 对象User、Person、TestModel1、TestModel2、ComplexModel
          User.java

public class User implements java.io.Serializable{
	private String id;
	private String userName;
	private String password;
	private int age;
	private List<String> friends;


	public String getid() {
		return id;
	}
	public void setId(String id) {
		this.id = id;
	}
	public String getUserName() {
		return userName;
	}
	public void setUserName(String userName) {
		this.userName = userName;
	}
	public String getPassword() {
		return password;
	}
	public void setPassword(String password) {
		this.password = password;
	}
	public int getAge() {
		return age;
	}
	public void setAge(int age) {
		this.age = age;
	}
	public List<String> getFriends() {
		return friends;
	}
	public void setFriends(List<String> friends) {
		this.friends = friends;
	}


}

         Person.java

public class Person implements java.io.Serializable{

}

         TestModel1.java

public class TestModel1 implements java.io.Serializable{

	    private User user;

	    private String keys;

	    private Map<String,String> params;

	    public String getKeys() {
	        return keys;
	    }

	    public void setKeys(String keys) {
	        this.keys = keys;
	    }

	    public Map<String, String> getParams() {
	        return params;
	    }

	    public void setParams(Map<String, String> params) {
	        this.params = params;
	    }

	    public User getUser() {
	        return user;
	    }

	    public void setUser(User user) {
	        this.user = user;
	    }

}

         TestModel2.java

public class TestModel2 implements java.io.Serializable{
	private User user;

    private int quantity;

    public int getQuantity() {
        return quantity;
    }

    public void setQuantity(int quantity) {
        this.quantity = quantity;
    }

    public User getUser() {
        return user;
    }

    public void setUser(User user) {
        this.user = user;
    }

}

         ComplexModel.java

public class User implements java.io.Serializable{
	private String id;
	private String userName;
	private String password;
	private int age;
	private List<String> friends;


	public String getid() {
		return id;
	}
	public void setId(String id) {
		this.id = id;
	}
	public String getUserName() {
		return userName;
	}
	public void setUserName(String userName) {
		this.userName = userName;
	}
	public String getPassword() {
		return password;
	}
	public void setPassword(String password) {
		this.password = password;
	}
	public int getAge() {
		return age;
	}
	public void setAge(int age) {
		this.age = age;
	}
	public List<String> getFriends() {
		return friends;
	}
	public void setFriends(List<String> friends) {
		this.friends = friends;
	}


}

        
         2.接口 PeopleService  实现PeopleServiceImpl
         PeopleService.java

public interface PeopleService extends Remote{
	
	public String showMessage(String name) throws RemoteException;

    public User getUser() throws RemoteException;

    public ComplexModel getModel() throws RemoteException;

    public void compareModel(ComplexModel model) throws RemoteException;

}

         PeopleServiceImpl.java

public class PeopleServiceImpl extends UnicastRemoteObject implements PeopleService{

	public PeopleServiceImpl() throws RemoteException {
		super();
		// TODO Auto-generated constructor stub
	}

	  public User getUser() throws RemoteException{

	        User result = new User();
	        result.setId("007");
			result.setUserName("zhangsan");
			result.setPassword("123456");
	        List<String> fs = new ArrayList<String>();
	        fs.add("sdsfdsfsd");
	        fs.add("sfsdfdsgsdf");
	        result.setFriends(fs);
	        return result;
	    }

	    public ComplexModel getModel() throws RemoteException{

	        ComplexModel model = new ComplexModel();

	        User user = new User();
	        user.setId("007");
			user.setUserName("zhangsan");
			user.setPassword("123456");
	        List<String> fs = new ArrayList<String>();
	        fs.add("sdsfdsfsd");
	        fs.add("sfsdfdsgsdf");
	        user.setFriends(fs);

	        TestModel1 m1 = new TestModel1();
	        m1.setUser(user);

	        TestModel2 m2 = new TestModel2();
	        m2.setUser(user);

	        model.setModel1(m1);
	        model.setModel2(m2);

	        System.out.println("....." + (model.getModel1().getUser() == model.getModel2().getUser()));
	        return model;
	    }

	    public void compareModel(ComplexModel model) throws RemoteException{
	        System.out.println("....." + (model.getModel1().getUser() == model.getModel2().getUser()));
	    }

		public String showMessage(String name)  throws RemoteException{
			// TODO Auto-generated method stub
			return null;
		}

}

         3 RMI绑定服务器  RMIServer
         RMIServer.java

public class RMIServer {

	/**
	 * @param args
	 */
	public static void main(String[] args) {

		try {
			LocateRegistry.createRegistry(9099);
			PeopleServiceImpl rmi = new PeopleServiceImpl();
			try {
				Naming.bind("//127.0.0.1:9099/RMI_SERVER",rmi);
				System.out.println("rmi对象已经注册到服务器上");
			} catch (MalformedURLException e) {
				e.printStackTrace();
			} catch (AlreadyBoundException e) {
				e.printStackTrace();
			}
		} catch (RemoteException e) {
			e.printStackTrace();
		}
	}

}

         4.RMI访问客户端  RMIClient
         RMIClient.java

public class RMIClient {

	/**
	 * @param args
	 */
	public static void main(String[] args) {
		for (int index = 0; index < 1000; index++) {
			try {
				PeopleService service = (PeopleService) Naming
						.lookup("//127.0.0.1:9099/RMI_SERVER");
				ComplexModel cm = service.getModel();
				System.out.println(cm.getModel1().getUser() == cm.getModel2()
						.getUser());
			} catch (MalformedURLException e) {
				e.printStackTrace();
			} catch (RemoteException e) {
				e.printStackTrace();
			} catch (NotBoundException e) {
				e.printStackTrace();
			}
		}
	}

}

       
         5.服务端核心代码
           注册端口  LocateRegistry.createRegistry(9099);
         绑定远程对象 Naming.bind("//127.0.0.1:9099/RMI_SERVER",rmi);
         6.客户端核心代码
           访问远程对象 PeopleService service = (PeopleService) Naming
.lookup("//127.0.0.1:9099/RMI_SERVER");
           7.测试结果： RMI能够实现不同版本的JVM之间传递复杂对象，并且能够传递引用参数。传输的对象必须实现java.io.Serializable接口。