Big ebooks site

http://ebuki.apvs.ru

Note: to download books you'll need to use Russian proxy server. Some you can find here: http://www.checker.freeproxy.ru/checker/last_checked_proxies.php

O'Reilly CD Bookshelves

A little bit old, but still may be helpful. Free online accessible O'Reilly CD Bookshelves includes the following:

• The Java Reference Library, version 1.3
• The Java Enterprise CD Bookshelf, Version 1.0
• The Perl CD Bookshelf, version 1.0
• The Perl CD Bookshelf, version 2.0
• The Networking CD Bookshelf, version 1.0
• The Networking CD Bookshelf, Version 2.0
• The UNIX CD Bookshelf, version 1.0
• Web Developer's Library
• The Oracle PL/SQL CD Bookshelf, version 1.0
• The Linux Web server CD Bookshelf, version 1.0
• Using Samba

More on RMI

Here's the tip how to manage Java security without creating the file policy.txt and without the java command line argument -Djava.security.policy=policy.txt. Just use this anonymous inner class when setting security manager:

System.setSecurityManager(new RMISecurityManager() {
    public void checkConnect(String host, int port) {}
    public void checkConnect(String host, int port, Object context) {}
});

Update: this trick doesn't work if you will use Java RMI for dynamic code downloading (using the java.rmi.server.codebase property), so stick with the command line argument -Djava.security.policy=policy.txt approach.

Update 2: if you'll use the following security manager it will work with dynamic code download:

System.setSecurityManager(new RMISecurityManager() {
    public void checkPermission(java.security.Permission perm) {}
});

Feel free to post your questions or comments.

RMI example in Java 2 Platform SE 5.0

RMI stands for Remote Method Invocation. As of the J2SE 5.0 release, stub classes for remote objects no longer need to be pregenerated using the rmic stub compiler, unless the remote object needs to support clients running in pre-5.0 VMs. So because I'm testing RMI with the JDK 5.0, I won't compile stub classes.

First define interface:

public interface Hello extends java.rmi.Remote {
    String sayHello() throws java.rmi.RemoteException;
}

Server class:

import java.rmi.*;
import java.rmi.registry.*;
import java.rmi.server.*;

public class Server implements Hello {
    public Server() {}
    public String sayHello() {
        return "Hello, world!";
    }
    public static void main(String args[]) {
        System.setSecurityManager(new RMISecurityManager());
        final Server obj = new Server();
        try {                               // 0 - anonymous TCP port ↓
            Hello stub = (Hello)UnicastRemoteObject.exportObject(obj, 0);
            // Bind the remote object's stub in the registry
            Registry registry = LocateRegistry.createRegistry(1099);
            registry.rebind("Hello", stub);
            for(int i = 0; i < registry.list().length; i++)
                System.out.println(registry.list()[i]);
            System.err.println("Server ready");
        } catch (Exception e) {
            e.printStackTrace();
        }
        // Needed for windows98 se, optional for windows xp
        new Thread() {
            public void run() {
                Server s = obj;
                while(true);
            }
        }.start();
    }
}

Client class:

import java.rmi.registry.*;
import java.rmi.*;

public class Client {
    private Client() {}
    public static void main(String[] args) {
        String host = (args.length < 1) ? null : args[0];
        try {
            Registry registry = LocateRegistry.getRegistry(host);
            Hello stub = (Hello)registry.lookup("Hello");
            // or Hello stub = (Hello)Naming.lookup("rmi://" + host + "/Hello");
            String response = stub.sayHello();
            System.out.println("response: " + response);
        } catch (Exception e) {
            System.err.println("Client exception: " + e.toString());
            e.printStackTrace();
        }
    }
}

Create file policy.txt with this text inside:

grant {
    // Allow everything for now
    permission java.security.AllPermission;
};

On the server computer run:

java -Djava.security.policy=policy.txt Server

On the client computer run:

java Client 192.168.0.3

Note: substitute ip address of your own or write hostname instead of ip address.

Feel free to post your questions or comments.