Hey, As summer time comes I've decided to further my horizons in java by attempting to make programs that would be run on the internet. I want to make a program that would save and load user data (think registering) but have been told java doesn't allow you to save stuff online. Can anyone tell me what I would need to use to make things savable from the internet? Also, can I run applications on the internet or strictly applets? Lastly, the book I use mentioned these things called beans. As I read about them, they seemed to be nothing different than java classes. Can anyone explain to me what they are?
Sorry for the rather broad nonspecific questions. For saving and loading, I wouldn't mind just being pointed in the direction as to what to look at as opposed to the specifics.
Thanks a lot, once more you guys are a great help. [ June 17, 2004: Message edited by: Matthew Fyffe ]
First of all, you've be the victim of some misinformation. You can process data (load, save, etc.) in a web environment using Java. The predominant, heavyweight technology to accomplish this is J2EE, however, you need not bother yourself with learning J2EE unless you're developing serious web apps. What you'd rather be interested in is some of the popular J2EE components, such as JSP, JavaBeans, and Servlets, which all work well stand-alone (given you have a container such as Tomcat).
JavaBeans are Java classes which follow a defined standard (most importantly, a constructor which takes no params). Beans operate in a web environment. You can develop some advanced applications online using JavaBeans (access data from database, process data, update database, etc.). Armed with JDBC, your Bean can run queries, call stored procedures, and interact in any number of ways with your database. Furthermore, you can use Servlets (or JSP) to interpret and process user input. JSP is usually reserved for formatting output and in order to follow good programming practice, you'll want to limit the amount of Java code you insert in your JSP pages.
I've got to run right now, but I'm sure some other Ranchers will provide some more explanation and tips.
There's many ways to build networked applications. Some of them don't allow interaction with the client machine, others do.
If you've been told Java can't access the harddisk, the person making that sweeping statement had only ever heard of applets and even then he'd be wrong (applets CAN access the harddisk of the client machine but extra special steps are needed to enable this for security reasons). Web applications can also not access the client machine, because they're limited to what a web browser can do. For security reasons webpages can't of course write or read your harddisk. That's not specific to Java.
If you write a full client application talking to your server, you can do everything you like.