j2me midlet signing for E71

Question

I have created a Midelt which accesses phone contact details [read and write contacts] and access network, this application is working fine S60 emulator.

When I try to install in Nokia E71, it is giving certification error.

I have created certificate using below link. When I try to install it in the phone still I am getting the certification error.

http://www.j2start.com/

Can anybody suggest, is there any way to test a midlet in actual Nokia e71 device without certificate from CA?

If certificate is mandatory,

which is the most suitable CA [Verisign or Thawte ] for Nokia E71?

Answer 1

It was stated in that page (where you signed your app) that the validity of the certificate is between Sept 1, 2010 to Sept 17, 2011. You need to set your device's date to any date between the validity period.

If the same error persists, try to check the certificates in the jad and check if the same certificate is in the phone.

1. Find JadTool.jar in your machine. You may find it in the Java SDK installation directory or WTK installation directory. If you can't find it then simply download it from the internet. For simplicity, put it in (root directory) C: (I'm assuming you're using Windows, if not then tell me later ;)).
2. Copy your signed jad file in C. (I want you to have both files, JadTool.jar and your app's jad file, in one directory, preferably C, as a prerequisite of the next steps :D)
3. Open terminal/command prompt. Go to C; type cd \ (Again, I'm assuming you're on Windows.)
4. Still on the terminal, type java -jar JadTool.jar -showcert -all -inputjad YourAppName.jad. Mind the case of the letters.
5. On the previous step, you can see which certificates are available in your jad file. You can see the details of each certificate. Let's focus on the fingerprints. If, for example, you see a Thawte certificate, take note of its SHA fingerprint.
6. Check the certificates in your device. The certificates are usually found in Security under Settings. If you have a Thawte certificate in the jad then you must check the Thawte certificates in the device. Compare the Thawte SHA fingerprint found in the jad against the Thawte fingerprint of the device. If they match then the app with this certificate is install-able on the device. If they don't match then it is more likely that you cannot use this certificate with your jad file.
7. Do steps 6 and 7 for the rest of the certificates. If you can't find any pair then, with the signing, it is more likely that you cannot install your app on your device.

By the way, you can still install your app on the device even if it is unsigned. One problem, if your app is unsigned, is that the user will be be bugged with security prompts. However, this can also be minimized. See my answer on how to minimize these prompts.

Answer 2

This could be the problem becase your either your certificate is old or just check the date on your phone. Your Phone might be running old date.