I want to write a yahoo! messenger and I create 2 java applications .one is for "server" and the other one is for" client" .at first I run the Server application and then I will run my GUI frame which is in my client application(So I will run my client application):it will show a frame that gets user name and password from a client . IF the user name and password were correct I will call the method which I create it in my client class which is in my ClientNetwork package(this package is in Client application).
Is this a correct way to run this program?
You will need to determine SOME protocol that will be used to communicate between the two programs. Also you most likely need it to be working over TCP/IP.
I would suggest you look into client/server programming. Here is the relevant Sun Java Tutorial page - http://java.sun.com/docs/books/tutorial/networking/sockets/
Also note that the username and password check should be done at the server. It wasn't quite clear from your question where the credentials are checked, but it's crucial not to do it at the client.
Anything that's done at the client can be potentially compromised, and you certainly don't want a malicious user to be able to log in with someone else's name.
Related
I'm working on a project I'm Java with regards to outlook.
Here I'm able to do all the functions like Read a mail, write a mail, reply to a mail etc...
But now we've been thinking of taking it to the next level.
Our plan is as below.
We have an email address like info#myDomain.com, when ever an email is sent to this address, I need to reply them. Here basically customers send an email asking for some data, and we've the data available in our portal, and we just need to send it.
The response would be Like thank you for contacting us, we will get back to you soon. Mean while please look into this {URL}.
And this has to be done automatically when ever there is an email hit to this particular email address.
Couple of questions:
- should my machine be on the whole day to get this thing done.
- is there a way that a Java application can automatically monitor my inbox to see for this case match.
- Also, can I have this running in the bg.
Can someone please point me into the right direction/approach where can I can start working on this task.
Thanks
when ever an email is sent to this address, I need to reply them.
For this you need to monitor your email account fro incoming emails. Here is one of the way to do this
The response would be Like thank you for contacting us, we will get back to you soon. Mean while please look into this {URL}.
Once you receive an email (using above email monitoring approach), you need to call a method that sends the reply with above format
And this has to be done automatically when ever there is an email hit to this particular email address.
Above two steps accomplishes this task.
should my machine be on the whole day to get this thing done
Basically, you will need an application server (like tomcat) where your above java program is deployed. So, yes this server needs to be running and available all the time.
is there a way that a Java application can automatically monitor my inbox to see for this case match
Check point 1
Also, can I have this running in the bg
You can run tomcat as a service in windows (more info). It has many advantages, automatic startup on boot being the one. Similar implementations are also available for other OS.
So, in short, this can be accomplished. It is bit complex but not much difficult. Cheers
I am trying to learn how to make a multiple-client chatting program. Im following the Oracle tutorial on Custom Networking, but its not really what I am looking for. So far, I have no code of my own to share, all of it is copied from the Oracle tutorial and I think pasting it here would be a copyright infringement(??).
link at: http://docs.oracle.com/javase/tutorial/networking/sockets/clientServer.html+
client code link: http://docs.oracle.com/javase/tutorial/displayCode.html?code=http://docs.oracle.com/javase/tutorial/networking/sockets/examples/KnockKnockClient.java
anyway, I have the server-client working where the server tells knock knock jokes, the client reads and prints, then the user replies and so on. how would i start to edit it to have the client talk to the other clients directly?
im sorry, i have no background with networking at all. if anyone can direct me to a informative source better suited to my goals i would appreciate it.
as in the Knock-Knock example, each client connects to the server, but they not mutually directly connected.
There is a solution to make a forwarding sever :Arrange each client an id, and clients use id to identify their talking partners.
To do this, you have to modify the client to server data format from a plain string to a tuple like (String,Id). And, when the server receive the data, it parses out the id, get the corresponding client socket and then write the data.
The required level of complexity just went up a notch as your going to need some sort of "interprocess communications" infrastructure to allow client to client communication (possibly via sockets marshalled by the server?)
I am making a Java based form desktop app, a mini login form, that will be able to login into a grand system which is online in asp.net.
The purpose of this app is to install on pcs, and whereever this exe is installed, the website could be logged in, other wise not.
The problem is, i have put the connection string of sql server in it, and employees will install this app on their machines, there is a tool available which decompile JAR and classes. And when i checked my classes in it, it was showing my sql server password. And it can give a chance to them to hack this app, this is really dangerous for us to provide them or give them a chance to get sql server password.
Can you please help, is there any such solution that i could give MD5 encrypted password or some encrypted password in connection string and sql server could be able to understand it.
Thanks
There are a few ways you can handle this.
the user info in your connection string should be limited to execute exactly one procedure: the one that tests if the MAC address is valid. This limits exposure. Not in an ideal way, but it's something.
Don't send a connection string at all. Instead have the java application post the mac address to a web service. The service should connect to the database server to determine authorization. Better than option 1.
Even better: Don't rely on MAC addresses. If you are worried that someone will look at the connection string then it stands to reason they might change their MAC address to mimic another machine. It stands to reason that anyone familiar enough to directly connect to a database server will also be familiar enough to download one of the many freely available tools to spoof their MAC.
Which leads to a comment: I think your doing this wrong. If the entire purpose of the java app is to simply read the MAC to validate whether that particular machine should have access then you have some serious issues with understanding security and I think you really need to evaluate what, exactly, it is you are trying to stop.
You can use integrated authentication, provided that the database server is in the same active directory domain as your users. Simply specify Integrated Security=SSPI in your connection string and grant regular users rights corresponding to what you want them to be able to do in the database (for example, read only access), but no more.
I have embedded a JSCH SSH Java applet in a web page and need to know if it's possible to run a script (of any language like PHP) to automate logging in and running commands. I have heard of expect4j and java robot but cannot see any way to implement it. Keep in mind, I'm not great with Java so I don't know everything about it. Any help is appreciated.
JSch is an SSH client library, and by itself only allows programmatically steered connections to another server. The user interaction has to be build around it by users of the library.
The JCTerm applet provided on the website also contains a terminal emulator in form of a Java GUI. If you only want to automatically execute some command (and maybe show its output in the web page), you could do everything on the server side, and don't need the applet with its terminal emulator. (You would need either some PHP-Java bridge on the server side or some Java-enabled webserver with a Servlet or similar, though.)
(If the web server would be the same machine as the server you'll run the command on you wouldn't even need the SSH connection, but could execute the stuff directly.)
If the server can't do anything (i.e. a "static server"), an applet is the way to go, yes. You can either modify JCTerm or create a new applet from scratch (using JCTerm's connection code as an example on how to connect to to the server).
If you don't have to fear any malicious users in your LAN (i.e. between web server and user, the SSH server doesn't matter), you can embedd the password (or preferably a private key for public-key authentication) into the applet's jar file, and pass it to the library for connection. (You should also include the server's public key for easier checking.)
Provide the command(s) to a ChannelExec (instead of a ChannelShell), this makes it easier to provide input (if necessary) and capture the output. Pipe the output in a text area, or simply use a green/red label saying if the command was successfully executed.
(I might have a look at this in the next days and try to do it. No promise, though.)
I've done quite a bit of research on this matter and I can't seem to come up with a solid solution to my problem.
I am developing a Java client application that (should) allow users to import their contacts from Mac Address Book by fetching them in a list format and allowing the user to select a subset/all and click a button that would send an "invitation" to these users.
I was able to grab contacts using the Rococoa Java framework but I am uncertain as to how to send email or if it is even possible. I realize there are security concerns with this, but I was able to accomplish this same task on Outlook for PC.
It seems that I may have to call an Applescript from my Java that manually opens Mac Mail Client and sends email using their default mail account setup.
I could be totally off-base here... should I even bother sending mail through the user's default Mail account? I wanted to avoid using a different mail server to avoid spam etc.
Any help would be appreciated, thank you for your time.
Matt
Here's an applescript to use Mail...
set emailSender to "sender#email.com>"
set emailTo to "recipient#email.com"
set theSubject to "The subject of the mail"
set theContent to "message body"
tell application "Mail"
set newMessage to make new outgoing message with properties {sender:emailSender, subject:theSubject, content:theContent, visible:true}
tell newMessage
make new to recipient at end of to recipients with properties {address:emailTo}
send
end tell
end tell
Another option, if you know the smtp information, is to use python. I made a command line program you can use. Find it here. There's example code to use it on the web page.