带有Jaudiotagger，NoClassDefFoundError的Jar文件

Question

I made a java class using the library Jaudiotagger, and it runs without problems. I then made a jar out of it and I got NoClassDefFoundError. Here's how it went:

I put the main class id3tag.java and the library jaudiotagger-2.0.3.jar in a folder and compiled using the command line. The program ran smoothly without problems.

javac -cp .;jaudiotagger-2.0.3.jar id3tag.java
java -cp .;jaudiotagger-2.0.3.jar id3tag

I then created the manifest and the jar file.

echo Main-Class: id3tag >manifest.txt
jar cvfm id3tag.jar manifest.txt id3tag.class jaudiotagger-2.0.3.jar

I got the following output:

added manifest
adding: id3tag.class(in = 5952) (out= 2997)(deflated 49%)
adding: jaudiotagger-2.0.3.jar(in = 811441) (out= 740599)(deflated 8%)

I then ran the jar file, and got "A Java Exception has occurred.". I also tried:

java -jar id3tag.jar

And I got the output:

Exception in thread "main" java.lang.NoClassDefFoundError: org/jaudiotagger/tag/
FieldDataInvalidException
        at java.lang.Class.getDeclaredMethods0(Native Method)
        at java.lang.Class.privateGetDeclaredMethods(Class.java:2451)
        at java.lang.Class.getMethod0(Class.java:2694)
        at java.lang.Class.getMethod(Class.java:1622)
        at sun.launcher.LauncherHelper.getMainMethod(LauncherHelper.java:494)
        at sun.launcher.LauncherHelper.checkAndLoadMain(LauncherHelper.java:486)

Caused by: java.lang.ClassNotFoundException: org.jaudiotagger.tag.FieldDataInval
idException
        at java.net.URLClassLoader$1.run(URLClassLoader.java:366)
        at java.net.URLClassLoader$1.run(URLClassLoader.java:355)
        at java.security.AccessController.doPrivileged(Native Method)
        at java.net.URLClassLoader.findClass(URLClassLoader.java:354)
        at java.lang.ClassLoader.loadClass(ClassLoader.java:423)
        at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:308)
        at java.lang.ClassLoader.loadClass(ClassLoader.java:356)
        ... 6 more

I then replaced all (both) error classes used from Jaudiotagger with Exception and recreated the jar. Now the same thing happens as for seemingly all other jar files when I run them (with Java(TM) Platform SE binary, or through writing id3tag.jar in the command prompt) - nothing. java -jar, however, works and gave me a runtime error.

Exception in thread "main" java.lang.NoClassDefFoundError: org/jaudiotagger/audi
o/AudioFileIO
        at id3tag.tagSong(id3tag.java:112)
        at id3tag.tagAlbum(id3tag.java:82)
        at id3tag.tagArtist(id3tag.java:40)
        at id3tag.main(id3tag.java:170)
Caused by: java.lang.ClassNotFoundException: org.jaudiotagger.audio.AudioFileIO
        at java.net.URLClassLoader$1.run(URLClassLoader.java:366)
        at java.net.URLClassLoader$1.run(URLClassLoader.java:355)
        at java.security.AccessController.doPrivileged(Native Method)
        at java.net.URLClassLoader.findClass(URLClassLoader.java:354)
        at java.lang.ClassLoader.loadClass(ClassLoader.java:423)
        at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:308)
        at java.lang.ClassLoader.loadClass(ClassLoader.java:356)
        ... 4 more

It seems like the entire library just doesn't do shit for me. How do I fix this, and how do I get jar files to run without java -jar? (Also, how do I get the full pile'o'errors in case someone needs it, rather than just having it say "x more"?)

I'm not very savvy with this kinda shit so the more specific the answer, the better. Thanks.

I'm on windows 8 and latest java (1.7.0_17).

Answer 1

this is informing you that you have no main class, as you might or might not already know all programs in almost all non web based programming languages must have a main class to start from. In java it looks like this

public static int main(String[] args){

}

The message is informing you that this class is no longer there, this could be a compiler error or something entirely different.

please try downloading the library again, and downloading eclipse ide for java ee developers. this ide has a built in compiler that will work better than a command line sometimes.

i hope this helped.

Answer 2

I worked around it by including the org folder from jaudiotagger in my .jar instead of the actual .jar file, and I then used a .bat file to run it instead of running the .jar directly. Feel free to add your own answer if you find a better solution, and I'll check back.

I extracted jaudiotagger-2.0.3.jar with winrar so that the org folder was in the same folder as my main class. Then I could compile and run the main class simply by:

javac id3tag.java
java id3tag

I then created the manifest file the same way as before, and created the jar:

jar cvfm id3tag.jar manifest.txt id3tag.class org

The jar file worked with java -jar id3tag.jar, but simply writing id3tag.jar still did nothing. Turns out it's because jar files are by default run by the javaw.exe file, so you have to right click the jar file -> open with -> choose default program and navigate to the java.exe file in your java folder (just search the folder). Running the .jar then gets you "Error: Could not find or load main class path\\id3tag.jar". I worked around this by using a .bat file. I entered

java -jar path\id3tag.jar

into Notepad and saved as whatevername.bat (save as type: all files).

I created a new question for getting the .jar file to work properly. See .jar error - could not find or load main class .