Memory gone CRAZY PLEASE help

Question

All,
This another question regarding my app, which has a main frame that contains Tabbedpane and have desktopPane attached inside. Within desktopPane I have multiple JInternalFrame. In each internalframe a textarea is attached for taking user input and displaying server feedback (the textarea has private classes that telnet to the server to do the input and output stuff).
I was testing my app last night and found out following problems:
1.) Memory just gone crazy! I opened several internal frames and did "cat *" on each of them just to test it out. I noticed the memory just gone crazy and the app become really slow responding. after I close the internal frames speed start getting better but memory is still not being released.
2.) I use InputStream.read() to read single byte from input stream. the return is an "int", I first convert it to a "char" and then cast it to a "string" then use the JTextArea.append("string") to append it to the textarea but it displays a little square after I press enter each time.
I appreciate your time and advise, thank you.

Answer 1

You can allocate extra memory to a Java program by putting something like
java -Xmx256m Myclass
That should tell you if running out of memory is really your problem.
Memory from abandoned items isn't recovered until the JVM decides to do a "garbage collection" which it doesn't usually bother with until it finds memory a bit tight.
You shouldn't cast byte input to char. In Java a character is a 16 bit UNICODE code value, and it's relationship with bytes depends on the "character encoding", by default the one native to your operating system.
If you want to read character input from a file etc. then use a Reader not an InputStream. If necessary you can "wrap" an input stream in an InputStreamReader object.
If you want to read it from the user in a Swing program then use an input field of some sort.