When should i implement java.io.Serializable in RMI?
I am just starting Java RMI and have some problems with when to use java.io.Serializable, so can anyone give me a RMI example that java.io.Serializable has to be implemented.
Thanks!!!
UPDATE: i had made a simple example, however, i think there are still problems as the output is not correct. Person Interface
package server; import java.rmi.Remote; import java.rmi.RemoteException; import java.rmi.server.UnicastRemoteObject;
public interface PersonInterface extends Remote
{
public void setName(String name) throws RemoteException;
public String getPerson() throws RemoteException;
public void setAddress(Address address) throws RemoteException;
}
Person Implementation
package server;
import java.rmi.server.UnicastRemoteObject;
import java.rmi.RemoteException;
import java.rmi.Naming;
import java.rmi.Remote;
class Person extends UnicastRemoteObject implements PersonInterface
{
private String name;
private int age;
private Address address;
Person() throws RemoteException {super();}
Person(String name,int age, Address address) throws RemoteException {
this.name = name;
this.age = age;
this.address = address;
}
public void setName(String name) throws RemoteException {
this.name = name;
}
public void setAddress(Address address) throws RemoteException{
this.address = address;
}
public String getPerson() throws RemoteException {
return "Person : " + name + " age : " + age + " address : " + address;
}
}
Address Class
package server;
import java.io.Serializable;
public class Address implements Serializable
{
private static final long serialVersionUID = 227L;
private String addre1;
private String addre2;
public Address() {}
public Address(String addre1,String addre2){
this.addre1 = addre1;
this.addre2 = addre2;
}
}
Server
package server;
import java.rmi.Naming;
class Server
{
public static void main(String[] args)
{
try{
//create an instance of the RemoteDatabaseServer
Person person = new Person();
//rmi://[host][:port]/object
String namePerson = "rmi://localhost:9999/person";
//bind this instance to localhost port999 with name database
Naming.bind(namePerson, person);
System.out.println("Server is running...");
}catch(Exception ex){
System.out.println("Server Exception...");
ex.printStackTrace();
}
}
}
Client
package client;
import java.rmi.RMISecurityManager;
import java.rmi.Naming;
import server.PersonInterface;
import server.Address;
class Client
{
public static void main(String[] args)
{
try{
System.setSecurityManager(new RMISecurityManager());
String namePerson = "rmi://localhost:9999/person";
PersonInterface person =
(PersonInterface)Naming.lookup(namePerson);
person.setName("myName");
System.out.println(person.getPerson());
person.setName("myNewName");
Address address = new Address("123","123");
person.setAddress(address);
System.out.println(person.getPerson());
}catch(Exception ex){
System.out.println("Client failure...");
ex.printStackTrace();
}
}
}
The output i got is
D:\java -Djava.security.policy=d:\Client\policy\client.policy client.Client Person : myName age : 0 address : server.Address@1d6776d Person : myNewN开发者_JS百科ame age : 0 address : server.Address@10a2d64
The address is not printed correctly PS: As you can see from Client class import
import server.PersonInterface;
import server.Address;
I had copy PersonInterface.class and Address.class to client side to make Client compiled.
Final: So stupid!!! Add following code to Address.java
public String toString(){
return addre1+ " " + addre2;
}
OK, problems are solved!! :)
interface MyInterface extends Remote {
MyClass f(MyClass x) throws RemoteException;
}
class MyClass implements Serializable {
private int value;
public MyClass(int value) {
this.value = value;
}
public int getValue() {
return value;
}
}
you need Serializable interface to tell that your class can be sent via network
server code
class Service extends UnicastRemoteObject implements MyInterface {
public Service() {
}
public MyClass f(MyClass v) throws RemoteException {
return new MyClass(v.getValue() + 1)
}
public static void main(Strint arg[]) {
Registry r = LocateRegistry.createRegistry(1099);
r.rebind("service", new Service());
}
}
client code
class Client {
public static void main(Strint arg[]) {
Registry r = LocateRegistry.getRegistry("localhost", 1099);
MyInterface service = (MyInterface)r.lookup("service");
MyClass result = service.f(new MyClass(123));
System.out.println(result.getValue()); //print 124 here
}
}
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