MIDP preverification snag: "java/lang/NoClassDefFoundError: javax/microedition/lcdui/CommandListener"

Posted on 2004-08-16
Last Modified: 2013-11-24
Java MIDP applications must be preverified before they can be executed on target devices.  (See

While attempting to preverify \\midp2.0fcs\src\example\ (which compiles just fine), I get the following error:

"Error preverifying class HelloMIDlet
    java/lang/NoClassDefFoundError: javax/microedition/lcdui/CommandListener"

This is odd, considering javax/microedition/lcdui/ (which does indeed contain CommandListener.class) is a subfolder of my classpath.  (If it wasn't, then the source obviously wouldn't have compiled in the first place.)

I did a search and found that the problem dates back to the year 2000.  (Nice.)  The only solution I found -- unpacking a midp.jar file and directing the classpath to a folder with its contents -- is no good, since there is no midp.jar file.

Has anyone successfully compiled  What is the solution to the java/lang/NoClassDefFoundError: javax/microedition/lcdui/CommandListener problem?
Question by:MiloDC
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LVL 35

Expert Comment

ID: 11808515
How do you compile it? Do you specify the classpath on the command line? If yes then you will also need to specify the classpath upon verification.

Author Comment

ID: 11808607
> girionis wrote:

> How do you compile it? Do you specify the classpath on the command line? If yes then you will also need to specify the classpath upon verification.

I do indeed specify the classpath during compilation and preverification.  Specifically:

javac -bootclasspath C:\midp2.0fcs\classes -deprecation -g -d "TmpClasses" -classpath C:\j2sdk1.4.2_05\lib\tools.jar;C:\j2sdk1.4.2_05\lib\;C:\midp2.0fcs\classes\;.

preverify -cldc -classpath C:\j2sdk1.4.2_05\lib\tools.jar;C:\j2sdk1.4.2_05\lib\;C:\midp2.0fcs\classes\;. TmpClasses -d "Classes"

Nevertheless, I get the error upon preverification.

Very odd.

LVL 35

Expert Comment

ID: 11808626
> Nevertheless, I get the error upon preverification.

Hmm.. You might not be able to use the -classpath switch with preverification. Can you do a preverify -help (or preverify --help)? YOu will probably get all the available switches that you can use with preverify.
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Author Comment

ID: 11808928
> girionis wrote:

> You might not be able to use the -classpath switch with preverification.

-classpath is a valid option.  This is confirmed in the documentation from Sun Microsystems.
LVL 35

Accepted Solution

girionis earned 125 total points
ID: 11809028
Weird, can you try that one:

preverify -cldc -classpath C:\j2sdk1.4.2_05\lib\tools.jar;C:\j2sdk1.4.2_05\lib\;C:\midp2.0fcs\classes;. TmpClasses -d "Classes"

(note that classes folder does not have a \ at the end). Not sure if this will help though.
LVL 35

Expert Comment

ID: 11809046
Can you also tell me if this class:

javax/microedition/lcdui/CommandListener is in a jar file or not? What happens if you put that jar file in the classpath?
LVL 18

Expert Comment

ID: 11810029
I use IDE JBuilderX. You can also download the trial version from JBuilder Site. It has 5-6 sample projects including Just run them using the IDE. I just changed the classpath a littlebit and they run fine in the emulator. .Jad files are also automatically made. I just sink them and they are running fine on my PocketPC

Author Comment

ID: 11812011
Thanks for the answer, girionis.  :)

The slash after "C:\midp2.0fcs\classes" was the culprit.  How lame.
LVL 35

Expert Comment

ID: 11812058
Well, computing is a bizarre field, even a little dot counts :)

Thank you for accepting, glad I was of help :)

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