I am puzzled a lot when I got emails with winmail.dat attachment, which is unknown file type attachment in my Thunderbird. Here is the solution for this annoying winmail.dat:
Go to https://addons.mozilla.org/en-US/thunderbird/addon/4433, follow it instructions to download the “LookOut” add-on for Thunderbird, and attached files inside winmail.dat will be listed and be recognized and be opened with existed programs.
Here is a task to challenge myself: Find the first k digits prime number. And k would be 16, 32, 64, 256, 1024, 8096, 65536, or even bigger.
Any comments about this challenge? Or join me to design the algorithm! Or join the distributed computing game.
Keep tuned for how big the number k would be!
PS: After searching around Internet for existed prime number theories, I find out that k=16 is already a challenge for me! There are algorithms to find prime number in format of 2^p+1, whose digits may be bigger than 1000000. But there are not the 1st k-digits algorithms. According to theories, I should have to find out all prime numbers less than given n. But the count of prime numbers less than n is about n / ln (n), which is huge number already for k=16! So my first challenge would be 16.
And now it is available for download. Please take a trial.
Sources of Java2Script Google Talk will be available in the next week. Keep tuned.
If you ever use Eclipse trying to debug into Java’s system APIs, such as java.lang.String or java.math.BigInteger, you may find that even you can step over or step in, or have the correct source file open and the correct line of codes highlighted, you still could not see the local variables’ value and method’s parameters are shown in pattern of “arg0”, “arg1” and so on.
Yes, you are already using JDK instead of JRE. But you still have the above problem. What’s wrong? It’s not a bug of Eclipse. It is all about the rt.jar along with the JDK (1.5 or 1.6). In Sun’s official JDK release, debug symbols are already packed into the rt.jar. But local variables’ debug information is not packed. Sun may consider that it is not OK to includes those local variables’ debugging information. That is the source of problem.
To solve this problem, you may need to upgrade to JDK 1.6. Download DEBUG jar file from
Double click it to install a new JDK. And configure your Eclipse to use the new JDK.
For JDK 1.5, recompiling rt.jar by yourself, or other information, please visit
for a detailed discussion.
Here is the screenshot:
En, in beta …