Running out of memory - where do I not free objects?

Question

Hello there,
I am analyzing data on an Itanium with 1GB of memory using the JSDK 1.4 (Java(TM) 2 Runtime Environment, Standard Edition (build 1.4.2-beta-b19)). I have a lot of memory troubles reading data as small as 120MB and processing it (using the Pattern class and ArrayList or static String array), so I wrote this little program to test the memory:
               print("Starting memcheck - press key...");
               int border= 100000;
               int bCount = border;
               int limit = 18000000;
               String tst = new String("Hi, Tester!");
               System.in.read();
               print("Key for 1-String-Buffer...");
               System.in.read();
               StringBuffer checkSt = new StringBuffer(limit*tst.length());
               print("1-String-Buffer created. Key for clearance...");
               System.in.read();
               checkSt = null;               
               System.gc();
               print("Key for Strings...");
               System.in.read();
               String [] checkS = new String[limit];
               for (int i=0; i<limit; i++) {
                    checkS[i] = (new String(tst));
                    if (--bCount == 0) {
                         bCount = border;
                         print("Created: "+i+" strings!");
               print("Strings created. Key for clearance...");
               System.in.read();
               checkS = null;               
               System.gc();As I originally thought, this only uses about 800MB with the static String array, 471MB with the StringBuffer, and crashes (out of memory) when being permitted up to 1000MB with ArrayList.
The odd thing is though, that when I put the part with the static String array after the StringBuffer part, it crashes too (out of memory). So I guess, that I have not fully understood how to free memory in java yet and that I am overlooking something here - can someone please help me? I have already tried for more than a week to fix this problem, but I must be overlooking the obvious...
According to my math, if I read 100MB, it should at most use 2*100MB+overhead (2* because of Java's internal unicode representation). Where am I doing wrong?
Thanks in advance!

Answer 1

Double posted,
http://forum.java.sun.com/thread.jsp?forum=31&thread=409677&tstart=0&trange=15