Song Lixin

+ Follow
since Nov 11, 2003
Cows and Likes
Total received
In last 30 days
Total given
Total received
Received in last 30 days
Total given
Given in last 30 days
Forums and Threads
Scavenger Hunt
expand Ranch Hand Scavenger Hunt
expand Greenhorn Scavenger Hunt

Recent posts by Song Lixin

I passed with 94. Here is my preparation process:
Time: 5/8 to 7/8 nearly 1.5 hours every morning and some hours in the weekend.

1. 5/8 to 5/28: I read a J2ME book and all specs and Java Ranch bbs. Only to get some idea.
2. 5/29 to 6/10: I read the book and specs and API documents and some articles.
3. 6/11 to 7/1 : I write some simple things and read Sytha's notes and take JMAD+ mock exam(The 5 test)
4. 7/2 to 7/7: I read Syhta's notes and take JMad+ practise test.
14 years ago
Thx a lot! All!
I have read all the spec and APIs and also Sathy's notes.

I will take the exam soon.
I had think that a Midlet is paused when it's brought background. And it's not running anymore there.
Today, I read the javadoc of Display and it's seems my option was wrong. Can somebody give me some hints about:
1) When will a Midlet get background?
2) When will a Midlet get foreground?
3) When a Midlet get background, will it's pauseApp get called?
4) When a Midlet's pauseApp get called?
5) When a Midlet's startApp get called?
Min non-volatile memory : 160k fou CLDC, 256k for MIDP, 8k for RMS
Min volatile memory: 128 k volatile memory

I still has not read JTWI so it's only mean for CLDC + MIDP.
In CLDC 1.1:

The CLDC Specification assumes that:
■ At least 160 kilobytes of non-volatile1 memory
machine and CLDC libraries.
■ At least 32 kilobytes of volatile memory2
runtime (for example, the object heap.)

In MIDP 2.0:

256 kilobytes of non-volatile memory for the MIDP implementation, beyond what's required for CLDC.
8 kilobytes of non-volatile memory for application-created persistent data
128 kilobytes of volatile memory for the Java runtime (e.g., the Java heap)

Does this means that for a MID that implements cldc1.1+midp2.0 will at least have:

160k+256K non-volatile memory and
8 + 128 k volatile memory

Thx 4 ur help! I just can not access this site, again
Can u send me one copy by email? or or
Sorry to disturbing you all.
It 's quite boring to read it! And becz I am a developer not a implementer, it's noting useful to me.
Dear All,
I am from a mobile design house and recently our company are evaluating SavaJe OS. Although I know it's about cldc/cdc, I would like to take the MAD exam first to be good prepared first for cldc/midp.
I have read many of the good posts here and thx a lot to many of owners and active plays such as Ko Ko.
From the forum, I see that Sathya's Notes will help a lot.
I tried many links and did not have the way of get it.
Can some one kindly help me?
BTW, I am from Shanghai, maybe somebody here have blocked my way.
Thx all! Thx Andrew!
It's a pity I am now working under
I don't know when I will be able to prepare SCEA.
I think only after I have finished a java project.
15 years ago

Thx very very much to JavaRanch Big Moose Saloon!
Next I will try XML.

Here are my results:
General Considerations (maximum = 100): 90
Documentation (maximum = 70): 70
O-O Design (maximum = 30): 30
GUI (maximum = 40): 28
Locking (maximum = 80): 80
Data store (maximum = 40): 40
Network server (maximum = 40): 40

15 years ago
Thx Andrew!
I declared an array of DBClient and initiate one by one. It seems no problem with 100 DBClient initiation. Because all the connections are made in one for phrase, The time difference must be quite little.

If I will set a limitation on the number of concurrent clients, I think 100 is quite good. Right?
Thx Andrew.
So what you mean is that I need not enfore a 20 limit?
I know only when using the testing code can I get the connection failure.
Thx Andrew!
1. Because I am at the final step of the program. I will choose to catch the RemoteException and make a retry.
2. I wrote the test code that spawn many threads and connect to the server simultaneously. Some threads got failed when the number of thread is set to more than 25 also. For example, when there are 100 threads, then maybe 80 threads will be able to connect to the server. I limit the Max concurrent client to 20 because in this way, the user get a Normal failure.(The client will get a prompt "Load too heavey")

[ November 10, 2004: Message edited by: Song Lixin ]
[ November 10, 2004: Message edited by: Song Lixin ]
Hello ranchers,
I think everyone using RMI should have meet the problem.But I searched and did not found any related thread.

We know that a live client reference has a lease with a specified time. If a client does not refresh the connection to the remote object before the lease term expires, the reference is considered to be dead and the remote object may be garbage collected. The lease time is controlled by the system property java.rmi.dgc.leaseValue. The value is in milliseconds and defaults to 10 minutes.

Because of these garbage collection semantics, a client must be prepared to deal with remote objects that have "disappeared."

My question is:
How does a client know that the remote object has "disappeared"?