Guide: How to write Kindlets

KukMan · 10-12-2010, 06:33 PM

Big thanks for adq and his lj entries.
All what I'll write I tested on my Kindle 3 wifi only.
Your must have jailbreaked Kindle to do this, have some skills with Linux systems and with Java.

First of all, we need get KDK jars files. You can copy it from your Kindle. Main KDK jar is located at /opt/amazon/ebook/lib/Kindlet-1.1.jar. Also you can pull off all jars from /opt/amazon/ebook/lib and /opt/amazon/ebook/sdk/lib folders.

Create Java project in your fav IDE ( I use NetBeans ). Add Kindlet-1.1.jar as library to your project ( depends from your IDE ). Hello World Example Kindlet is under spoiler. You would be able to compile it at this step.

Spoiler:

You must change Manifest file in your project. It's depends from you IDE also. You must add this lines to it:
Code:
```
Implementation-Title: Your_App_Name
Implementation-Version: Your_App_Verion
Implementation-Vendor: Your_Name
```
Don't forget change lines with your data.
At this step, we have jar file with valid Manifest file. You can try change filename from *.jar to *.azw2, copy it into documents folder on USB mass storage and run, but you wouldn't be able do this. This is normal.
Note, that you can check manifest, unzip jar file and see it in META-INF folder.

Create own keystore with pairs of keys for signing own kindlets. "keytool" helps us. For creating keystore execute this commands:

Code:

keytool -genkeypair -keystore developer.keystore -storepass YOURPASS_FOR_STORE -keypass YOURPASS_FOR_KEY -alias dkYOUR_ALIAS -dname "CN=Unknown, OU=Unknown, O=Unknown, L=Unknown, ST=Unknown, C=Unknown" -validity 5300
keytool -genkeypair -keystore developer.keystore -storepass YOURPASS_FOR_STORE -keypass YOURPASS_FOR_KEY -alias diYOUR_ALIAS -dname "CN=Unknown, OU=Unknown, O=Unknown, L=Unknown, ST=Unknown, C=Unknown" -validity 5300
keytool -genkeypair -keystore developer.keystore -storepass YOURPASS_FOR_STORE -keypass YOURPASS_FOR_KEY -alias dnYOUR_ALIAS -dname "CN=Unknown, OU=Unknown, O=Unknown, L=Unknown, ST=Unknown, C=Unknown" -validity 5300

Note, that dk, di and dn suffixes in aliases is necessary.
Alias is case-insensitive. For example:

Code:

keytool -genkeypair -keystore developer.keystore -storepass passwork -keypass password -alias dnTest -dname "CN=Unknown, OU=Unknown, O=Unknown, L=Unknown, ST=Unknown, C=Unknown" -validity 5300

Copy this keystore to /var/local/java/keystore/developer.keystore

Sign jar file executing this command:

Code:

jarsigner -keystore KEYSTORE_FILE -storepass KEYSTORE_PASS JAR_FILE dkYOUR_ALIAS
jarsigner -keystore KEYSTORE_FILE -storepass KEYSTORE_PASS JAR_FILE diYOUR_ALIAS
jarsigner -keystore KEYSTORE_FILE -storepass KEYSTORE_PASS JAR_FILE dnYOUR_ALIAS

For example:

Code:

jarsigner -keystore develop.keystore -storepass password ~/projects/test/dist/test.jar dnTest

Copy signed jar into Kindle, rename it to *.azw2, and try to run.
Note, that you must restart your Kindle after copying develop.keystore to it.

P.S. If you want to know more, you can read adq's entries in his LiveJournal about this.

P.S.S. I suggest create one public develop.keystore, and sign all free apps. It prevents problem with apps from different developers. Or how can I merge keystore from another developer with mine?

neftaly · 10-13-2010, 01:15 AM

Thanks for writing this. I thought it might be a good idea to use the keystore that ADQ made with his first working app, "ktest":
-storepass password -keypass password -alias dktest/ditest/dntest
I've repackaged some of his files (K3 automatic key installer, jar signer script etc) and put them up at http://kindlebru.com/devkeys.zip. These should probably be fine for signing apps in the near future.

The manifest line Amazon-Cover-Image: logo.jpg will include a thumbnail (rel to the root of the jar archive). Thumbnails can be viewed by pressing the right donut button over the app. Full-colour jpeg and png images are supported, and are automatically scaled to approx 200x200 (official apps seem to use images closer to 500x500px).

For anybody else having trouble getting Kindlet jars off the device, I've also got them up at http://kindlebru.com/libs.zip (had trouble telnetting, so I just created an updater script with the command "cp -r /opt/amazon/ebook/lib/* /mnt/us/lib").

The manifest of one of the official Active Content apps has the line Network-Access-Grants: sponsored. Is this necessary to use 3G data?

jozicka · 10-14-2010, 01:06 PM

small question - how hard is to tranform any jar to azw2?

(something like opera.azw2 )

KukMan · 10-14-2010, 03:26 PM

jar - is simple zip file and azw2 is simple zip file. It is significant what inside archive. You can't get opera mini for mobiles and run it on kindle. You need sources of midlet and change it to run on Kindle.

kranu · 11-23-2010, 06:28 PM

Gaaaah!

No matter how hard I try to follow this and ADQ's blog, I can't get it to show up on my Kindle! It compiles with no errors and what not.. and I've signed it and loaded the developer keys, but it does not show up on my Kindle screen. I've tried restarting multiple times too. The code is, as far as I can tell, very similar to ADQ's, which works perfectly on my Kindle.

I'm pretty new to Java, so it is probably something obvious that I am forgetting to do. If somebody could help me tell me what's wrong, I would be eternally grateful.

dvhh · 11-24-2010, 01:40 AM

I admit that this would be :
1. unsafe
2. not designed at all for "legitimate" application
3. should not be used by people who want to put their application on the amazon market later

But :
1. give access to all the jre object
2. allow the application to spawn some sub process (like using arecord command to record sound for example).
3. create a parallel market to the amazon one for application.
4. give dev more control over their platform.

However I admit that this is not safe at all, and you could end up fucking up your whole kindle.

kindle3zeng · 12-16-2010, 12:48 PM

Quote:

Originally Posted by kranu

Gaaaah!

No matter how hard I try to follow this and ADQ's blog, I can't get it to show up on my Kindle! It compiles with no errors and what not.. and I've signed it and loaded the developer keys, but it does not show up on my Kindle screen. I've tried restarting multiple times too. The code is, as far as I can tell, very similar to ADQ's, which works perfectly on my Kindle.

I'm pretty new to Java, so it is probably something obvious that I am forgetting to do. If somebody could help me tell me what's wrong, I would be eternally grateful.

I'm new to java also, but I just managed to get my first kindlet run.

I took a look at your package, I'm not sure what tool you used to package it. But I used ellipse, and exported it as a jar file, using a manifest file:

Code:

Manifest-Version: 1.0
Description: Test for Kindle
Main-Class: test.Main
Implementation-Title: Hello
Implementation-Version: 0.0.1
Implementation-Vendor: Me

At first, I didn't include

Code:

Description: Test for Kindle
Main-Class: test.Main

which caused my kindlet not to show up.

With these lines added, it ran like a charm.

kranu · 12-17-2010, 02:08 AM

Quote:

Originally Posted by kindle3zeng

I'm new to java also, but I just managed to get my first kindlet run.

I took a look at your package, I'm not sure what tool you used to package it. But I used ellipse, and exported it as a jar file, using a manifest file:

Code:

Manifest-Version: 1.0
Description: Test for Kindle
Main-Class: test.Main
Implementation-Title: Hello
Implementation-Version: 0.0.1
Implementation-Vendor: Me

At first, I didn't include

Code:

Description: Test for Kindle
Main-Class: test.Main

which caused my kindlet not to show up.

With these lines added, it ran like a charm.

Well, I already had the Main-Class line, but I added the description line, and the Kindlet magically appeared on my screen! I'm not sure why this happened, because when I removed the line from my code and reuploaded, the Kindlet did not disappear.

I suspect that the problem could have been with the fact that I was using the 64-bit eclipse, but I compiled this one with 32-bit eclipse. Unfortunately, I have no way of checking because I wiped out my computer, but thanks for your help! Now I can finally try some developing

dvhh · 12-21-2010, 05:39 AM

Made it read a buffer.txt at start for recovery, and write it back before stopping.
Tried to fiddle with the anti aliasing, but the speed impact is really too strong, and the "symbole" window position is an issue if you type long text.
Oh and no scroll bars yet.

it also learned me that alt+del remove the whole field content.
source are provided as I don't have any rights on them, and as usual use at your own risk.

dvhh · 12-26-2010, 03:07 PM

New hints
http://blog.tkxuyen.com/2010/10/kind...g-and-kdk.html
which goes
http://apetresc.wordpress.com/2010/07/03/kindle-goban/
https://github.com/apetresc/KindleGoban
https://github.com/apetresc/KindleChess

these code are suppose to work under the simulator

dvhh · 12-26-2010, 10:04 PM

We are Still missing the piece where we could load resources from the jar, I'm thinking of going around it by pre-processing the resources to convert them into java byte arrays.

apetresc · 12-28-2010, 05:32 PM

Quote:

Originally Posted by dvhh

New hints
http://blog.tkxuyen.com/2010/10/kind...g-and-kdk.html
which goes
http://apetresc.wordpress.com/2010/07/03/kindle-goban/
https://github.com/apetresc/KindleGoban
https://github.com/apetresc/KindleChess

these code are suppose to work under the simulator

Hey guys; I'm the author of KindleGoban, KindleChess, and Kindle Widget Toolkit (KWT). Let me know if you guys have any questions about building or running any of those. I've only had experience going through the KDK, not the jailbreak, but I'll do my best if problems come up with anything I did.

Cheers!
-Adrian

kindle3zeng · 12-29-2010, 05:26 PM

Quote:

Originally Posted by apetresc

Hey guys; I'm the author of KindleGoban, KindleChess, and Kindle Widget Toolkit (KWT). Let me know if you guys have any questions about building or running any of those. I've only had experience going through the KDK, not the jailbreak, but I'll do my best if problems come up with anything I did.

Cheers!
-Adrian

Hey, Adrian. Thanks for your great work, I looked KWT, it is really cool.

What I need is an example for multi-page display, I could not figure out how to do that, I've heard that there was an example in KDK, but I don't have that, so could you give me an example/hint on that?

azit · 12-30-2010, 03:58 AM

Hi Adrian,

Quote:

Originally Posted by apetresc

Hey guys; I'm the author of KindleGoban, KindleChess, and Kindle Widget Toolkit (KWT). Let me know if you guys have any questions about building or running any of those. I've only had experience going through the KDK, not the jailbreak, but I'll do my best if problems come up with anything I did

I've managed to compile your KindleChess to run on a jailbroken kindle 3. I reduced the square size to 64x64 so it would fit on the screen, as it appears you originally wrote it for a dx. I then created 64x64 images for the pieces. It's a bit of a mess as I've only spent a couple of hours on it and I have to figure out how to debug it. Since I don't have a simulator I can only run it on the kindle which is a bit of a pain. Progress so far attached.

Edit. Now working, but with some refresh issues at startup. Seems the board isn't all displayed, perhaps because the images haven't been read in in time? Just got to fix the grey scale background for black.

Cheers,
Paul

apetresc · 12-31-2010, 12:46 AM

Quote:

Originally Posted by kindle3zeng

Hey, Adrian. Thanks for your great work, I looked KWT, it is really cool.

What I need is an example for multi-page display, I could not figure out how to do that, I've heard that there was an example in KDK, but I don't have that, so could you give me an example/hint on that?

Hey kindle3zeng. Glad to get some feedback

The sample code for multi-page displays in the KDK (SamplePagedData) is known to be broken, several people on the developer forums have reported it. I did manage to get it working on my own though -- I have a really simple multi-page display in KindleGoban; check out line 160 of Main.java (that app is in the middle of a major refactoring, sorry about the mess

)

Let me know if that's enough of an example, or if you have specific questions about something that's not working.

Cheers!
-Adrian

10-12-2010, 06:33 PM	#1
KukMan Member Posts: 12 Karma: 2600 Join Date: Oct 2010 Device: Kindle 3 Wi-fi US	Guide: How to write Kindlets Big thanks for adq and his lj entries. All what I'll write I tested on my Kindle 3 wifi only. Your must have jailbreaked Kindle to do this, have some skills with Linux systems and with Java. First of all, we need get KDK jars files. You can copy it from your Kindle. Main KDK jar is located at /opt/amazon/ebook/lib/Kindlet-1.1.jar. Also you can pull off all jars from /opt/amazon/ebook/lib and /opt/amazon/ebook/sdk/lib folders. Create Java project in your fav IDE ( I use NetBeans ). Add Kindlet-1.1.jar as library to your project ( depends from your IDE ). Hello World Example Kindlet is under spoiler. You would be able to compile it at this step. Spoiler: Code: package test; import com.amazon.kindle.kindlet.AbstractKindlet; import com.amazon.kindle.kindlet.KindletContext; import com.amazon.kindle.kindlet.ui.KTextArea; public class Main extends AbstractKindlet { private KindletContext ctx; public void create(KindletContext context) { this.ctx = context; } public void start() { try { ctx.getRootContainer().add(new KTextArea("Hello World!")); } catch (Throwable t) { t.printStackTrace(); } } } You must change Manifest file in your project. It's depends from you IDE also. You must add this lines to it: Code: Implementation-Title: Your_App_Name Implementation-Version: Your_App_Verion Implementation-Vendor: Your_Name Don't forget change lines with your data. At this step, we have jar file with valid Manifest file. You can try change filename from .jar to .azw2, copy it into documents folder on USB mass storage and run, but you wouldn't be able do this. This is normal. Note, that you can check manifest, unzip jar file and see it in META-INF folder. Create own keystore with pairs of keys for signing own kindlets. "keytool" helps us. For creating keystore execute this commands: Code: keytool -genkeypair -keystore developer.keystore -storepass YOURPASS_FOR_STORE -keypass YOURPASS_FOR_KEY -alias dkYOUR_ALIAS -dname "CN=Unknown, OU=Unknown, O=Unknown, L=Unknown, ST=Unknown, C=Unknown" -validity 5300 keytool -genkeypair -keystore developer.keystore -storepass YOURPASS_FOR_STORE -keypass YOURPASS_FOR_KEY -alias diYOUR_ALIAS -dname "CN=Unknown, OU=Unknown, O=Unknown, L=Unknown, ST=Unknown, C=Unknown" -validity 5300 keytool -genkeypair -keystore developer.keystore -storepass YOURPASS_FOR_STORE -keypass YOURPASS_FOR_KEY -alias dnYOUR_ALIAS -dname "CN=Unknown, OU=Unknown, O=Unknown, L=Unknown, ST=Unknown, C=Unknown" -validity 5300 Note, that dk, di and dn suffixes in aliases is necessary. Alias is case-insensitive. For example: Code: keytool -genkeypair -keystore developer.keystore -storepass passwork -keypass password -alias dnTest -dname "CN=Unknown, OU=Unknown, O=Unknown, L=Unknown, ST=Unknown, C=Unknown" -validity 5300 Copy this keystore to /var/local/java/keystore/developer.keystore Sign jar file executing this command: Code: jarsigner -keystore KEYSTORE_FILE -storepass KEYSTORE_PASS JAR_FILE dkYOUR_ALIAS jarsigner -keystore KEYSTORE_FILE -storepass KEYSTORE_PASS JAR_FILE diYOUR_ALIAS jarsigner -keystore KEYSTORE_FILE -storepass KEYSTORE_PASS JAR_FILE dnYOUR_ALIAS For example: Code: jarsigner -keystore develop.keystore -storepass password ~/projects/test/dist/test.jar dnTest Copy signed jar into Kindle, rename it to .azw2, and try to run. Note, that you must restart your Kindle after copying develop.keystore to it.* P.S. If you want to know more, you can read adq's entries in his LiveJournal about this. P.S.S. I suggest create one public develop.keystore, and sign all free apps. It prevents problem with apps from different developers. Or how can I merge keystore from another developer with mine? Last edited by KukMan; 10-12-2010 at 07:29 PM.

10-13-2010, 01:15 AM	#2
neftaly Junior Member Posts: 8 Karma: 2600 Join Date: Oct 2010 Device: none	Thanks for writing this. I thought it might be a good idea to use the keystore that ADQ made with his first working app, "ktest": -storepass password -keypass password -alias dktest/ditest/dntest I've repackaged some of his files (K3 automatic key installer, jar signer script etc) and put them up at http://kindlebru.com/devkeys.zip. These should probably be fine for signing apps in the near future. The manifest line Amazon-Cover-Image: logo.jpg will include a thumbnail (rel to the root of the jar archive). Thumbnails can be viewed by pressing the right donut button over the app. Full-colour jpeg and png images are supported, and are automatically scaled to approx 200x200 (official apps seem to use images closer to 500x500px). For anybody else having trouble getting Kindlet jars off the device, I've also got them up at http://kindlebru.com/libs.zip (had trouble telnetting, so I just created an updater script with the command "cp -r /opt/amazon/ebook/lib/* /mnt/us/lib"). The manifest of one of the official Active Content apps has the line Network-Access-Grants: sponsored. Is this necessary to use 3G data? Last edited by neftaly; 12-14-2010 at 08:00 PM.

11-24-2010, 01:40 AM	#6
dvhh Enthusiast Posts: 27 Karma: 2600 Join Date: Nov 2010 Location: Osaka, Japan Device: Kindle 3	what about modifying the policy files instead of setting dev key I admit that this would be : 1. unsafe 2. not designed at all for "legitimate" application 3. should not be used by people who want to put their application on the amazon market later But : 1. give access to all the jre object 2. allow the application to spawn some sub process (like using arecord command to record sound for example). 3. create a parallel market to the amazon one for application. 4. give dev more control over their platform. However I admit that this is not safe at all, and you could end up fucking up your whole kindle.

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10-14-2010, 01:06 PM	#3
jozicka Connoisseur Posts: 63 Karma: 194 Join Date: Feb 2010 Device: notebook	small question - how hard is to tranform any jar to azw2? (something like opera.azw2 )

10-14-2010, 03:26 PM	#4
KukMan Member Posts: 12 Karma: 2600 Join Date: Oct 2010 Device: Kindle 3 Wi-fi US	jar - is simple zip file and azw2 is simple zip file. It is significant what inside archive. You can't get opera mini for mobiles and run it on kindle. You need sources of midlet and change it to run on Kindle.

12-26-2010, 03:07 PM	#10
dvhh Enthusiast Posts: 27 Karma: 2600 Join Date: Nov 2010 Location: Osaka, Japan Device: Kindle 3	New hints http://blog.tkxuyen.com/2010/10/kind...g-and-kdk.html which goes http://apetresc.wordpress.com/2010/07/03/kindle-goban/ https://github.com/apetresc/KindleGoban https://github.com/apetresc/KindleChess these code are suppose to work under the simulator

12-26-2010, 10:04 PM	#11
dvhh Enthusiast Posts: 27 Karma: 2600 Join Date: Nov 2010 Location: Osaka, Japan Device: Kindle 3	We are Still missing the piece where we could load resources from the jar, I'm thinking of going around it by pre-processing the resources to convert them into java byte arrays.