Jar vs jad

As far as I understand it the .Jad file simply contains a discription of the jar file which the phone reads proir to installation.

[quote="willbrady"]As far as I understand it the .Jad file simply contains a discription of the jar file which the phone reads proir to installation.[/quote]

THAT'S CORRECT!

.jad --> MIME type == text/vnd.sun.j2me.app-descriptor
.jar --> MIME type == application/java-archive

When you upload a .jar directly from yout PC to the phone, thye .JAD is completly USELESS 😊

but i thought that 6610, 7210 and all used jad files only. if they are read files hoe they work on those phones. ? ?

[quote="Jesal"]but i thought that 6610, 7210 and all used jad files only. if they are read files hoe they work on those phones. ? ?[/quote]Incorrect. The executable programs are still delivered in a .jar, the .jad is still a description file (that tells where the actual .jar, which is really just a compressed ZIP format file with the executable midlet inside, is).

ahhhh thx for the info i remember puttin a jad file in my 6610 some time back so i thought as much. neways now i know. hehe. so will all the java games work on the p800 and the o2 xda as well ?

The p800 supports MIDP and Personal Java so i guess there is even more java apps/games for the p800.

Not too many games written using pJava, as far as I'm aware.

In any case, the MIDP (Mobile Information Device Profile) Java specification v1.0 left out many things, so phone manufacturers added many extensions of their own (e.g., to accommodate larger screen sizes, access to vibration API's, etc., etc.). In practice this means many MIDP applications (or so called midlets) may or may not work on different phones depending on whether they've been developed to the spec, or using vendor-specific extensions.

MIDP v2.0 expands the functionality by quite a bit (and standardizes many of the things vendors had to invent on their own), but still leaves quite many things as "optional" (which means that that vendors may or may not implement them). That means that a developer using optional features is not guaranteed to have them available on every phone.

In addition to that, vendors are working (through the Java Community Process or JCP) to decide what, exactly, in MIDP v2.0 is really optional. That effort is known as JSR-185 or Java Technology for the Wireless Industry, JTWI.

No MIDP v2.0 phones are out yet. Nokia announced at the July Java One conference that the 6600 would be the first Nokia phone with MIDP v2.0 support. I haven't seen any other vendors announce specific models with MIDP v2.0 yet.

Personal Java or pJava seems to be on its way out (so I wouldn't expect any more phones appear on the market with pJava). I know of only two phones with it: the Nokia Communicator (9210/9210i/9290) and the Sony Ericsson P800/P802 with pJava.

Anyone inteterested in more "Mobile Java" a.k.a. J2ME (Java 2 Mobile Edition) a.k.a. MIDP/CLDC, can read more through the links below:

http://java.sun.com/
http://java.sun.com/j2me/
http://java.sun.com/products/jtwi/
http://jcp.org/en/jsr/detail?id=185