devxlogo

The Latest

Creating Applet to Ping IP Address

Question: I would like to create a very simple applet that pings anIP address and returns a message stating whether that IP is alive. Icouldn’t find any straightforward answers to

Creating a Dialog Box

Question: I’ve been to sites where dialog boxes appear. How can I create one?I also want to ask users for their names, and then to be able to tell how

Why doesn’t the window.close() method always work?

Question: Why doesn’t the window.close() method always work? Answer: In JavaScript 2.0, the window.close() method could be used to close any open browser window. People being the malicious animals that

How do I implement classic algorithms in C?

Question: Where can I find algorithms and data structures, techniques and programs that will better show me how they can be implemented using ANSI C? Other areas include Hashing, Heaps,

Creating TextField to Handle Passwords

Question: How do I create a TextField that handles a password?What are the KEY_ACTION events associated with it? Answer: The setEchoCharacter() method within the TextField class allows youto do precisely

Using Java to Control System Functions

Question: I would like to be able to browse my server and havean applet/program that would mimic the functions of,say, the control panel on a Macintosh.Would I needto write a

Will Downloading Java Applets Fill Hard Disk?

Question: Constant downloading and fear of accumulating masses of useless files is turning me off on Internet. My concept of Java is that exe files, etc., will be on the

Can Java Communicate with Local Serial Port?

Question: Is it possible to have Java talk to a localserial port on a machine, for example,COM1 or COM2 on a PC?Is there a way to do this without nativemethods,

Can I Add Menu Bars to Applets?

Question: Is it possible to add a menu bar to an applet without usingFrame as the container?Also, is it possible to show a Frame without a new window poppingup?I am

Responding to Mousedown Event in TextField

Question: How can I respond to a mousedown event in a TextField? Answer: From the Java 1.0.2 API specs:“In Java 1.0, the AWT does not send mouse or focus events

How to Fix Drop-down Box Conflict in Applet

Question: I am unable to run an applet and use a drop-downbox on the same page when using Netscape. The page hasmassive flickering and the applet will sometimes run. Theapplet

Equivalent of void myRoutine in Java?

Question: I know that in order to pass something byreference, you pass an already-created objectand let the subroutine modify the contents ofthat object. Unfortunately, the Integer, String,etc. objects don’t allow

Launching Another Application from Java

Question: Is it possible to launch another application from aJava application (not an applet)? Answer: Yes. There are two classes of interest for performingsystem level functions such as this: java.lang.Runtime

Appending to a File

Question: How can I append to a file in Java?The file is ASCII. It exists. The program hasrights to the file. I just need to add to the endof the

How to calculate sqrt()

Question: How do you calculate sqrt()? Answer: Of course the best way to compute square roots is to useMath.sqrt(),but I assume your question is academic. I’m not sure of the

Passing Data Between Two Threads

Question: I am new to Java and am currently trying toassociate idioms and techniques from otherlanguages/environments with like capabilities inJava. Specifically, I am trying to determine howto perform inter-thread and

What is the Thread.interrupt()method’s purpose?

Question: What is the purpose of the Thread.interrupt()method? I expect that if I call the interrupt()method of a sleeping thread, anInterruptedException will be thrown. Here is aquick code sample showing

Using .net Classes to Log On to Mail Server

Question: How do I use the .net classes to log on to a mailserver and request, say, the number of new mailmessages? Or send a message?Just POP3/SMTP. An example would

Why Does Spawned Thread Work on PC and not Sun?

Question: This may be too vague, but:I spawn a thread (after a button click) which bringsup a new window. This works great on my PC runningNetscape 3.0 and Internet Explorer,

How to Prevent Simultaneous Access

Question: How do you lock a file in Java to prevent simultaneous multipleaccesses? Answer: If you’re concerned about simultaneous access by independent processes,you’ll have to rely on the host OS

Reading from URL into String

Question: What is the maximum size of a string array I can have in my applet?I am trying to store some stock prices in a string array after reading themfrom