Question

hi
i am doing a program for reading mp3 header. i get reading source code from the site.
if aware of this site or mp3 header reading. please help me.

code is:

    File oSourceFile = new File("D:\\Mp3\\a.mp3");

    // create an MP3File object representing our chosen file
    MediaFile oMediaFile = new MP3File(oSourceFile);

    // any tags read from the file are returned, in an array, in an order which you should not assume
    ID3Tag[] aoID3Tag = oMediaFile.getTags();
    // let's loop through and see what we've got
    // (NOTE:  we could also use getID3V1Tag() or getID3V2Tag() methods, if we specifically want one or the other)
    for (int i=0; i < aoID3Tag.length; i++)
    {
        // check to see if we read a v1.0 tag, or a v2.3.0 tag (just for example..)
        if (aoID3Tag[i] instanceof ID3V1_0Tag)
        {
            ID3V1_0Tag oID3V1_0Tag = (ID3V1_0Tag)aoID3Tag[i];
            // does this tag happen to contain a title?
            if (oID3V1_0Tag.getTitle() != null)
            {
                System.out.println("Title = " + oID3V1_0Tag.getTitle());
            }
            // etc.
        }
        else if (aoID3Tag[i] instanceof ID3V2_3_0Tag)
        {
            ID3V2_3_0Tag oID3V2_3_0Tag = (ID3V2_3_0Tag)aoID3Tag[i];
            // check if this v2.3.0 frame contains a title, using the actual frame name
            if (oID3V2_3_0Tag.getTIT2TextInformationFrame() != null)
            {
                System.out.println("Title = " + oID3V2_3_0Tag.getTIT2TextInformationFrame().getTitle());
            }
            // but check using the convenience method if it has a year set (either way works)
            try
            {
                System.out.println("Year = " + oID3V2_3_0Tag.getYear());  // reads TYER frame
            }
            catch (ID3Exception e)
            {
                // error getting year.. if one wasn't set
                System.out.println("Could get read year from tag: " + e.toString());
            }
            // etc.
        }
    }

run the code i get java.lang.NoClassDefFoundError:

my console output:

  Exception in thread "main" java.lang.NoClassDefFoundError: junit/framework/TestCase
at java.lang.ClassLoader.defineClass1(Native Method)
at java.lang.ClassLoader.defineClass(Unknown Source)
at java.security.SecureClassLoader.defineClass(Unknown Source)
at java.net.URLClassLoader.defineClass(Unknown Source)
at java.net.URLClassLoader.access$000(Unknown Source)
at java.net.URLClassLoader$1.run(Unknown Source)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(Unknown Source)
at java.lang.ClassLoader.loadClass(Unknown Source)
at sun.misc.Launcher$AppClassLoader.loadClass(Unknown Source)
at java.lang.ClassLoader.loadClass(Unknown Source)
at java.lang.ClassLoader.loadClassInternal(Unknown Source)
at org.blinkenlights.jid3.test.ID3Test.testWriteV1_0Tag(ID3Test.java:60)
at org.blinkenlights.jid3.test.ID3Test.main(ID3Test.java:46)
    Caused by: java.lang.ClassNotFoundException: junit.framework.TestCase
at java.net.URLClassLoader$1.run(Unknown Source)
at java.security.AccessController.doPrivileged(Native Method)
     --- testWriteV1_0Tag ---

at java.net.URLClassLoader.findClass(Unknown Source)
at java.lang.ClassLoader.loadClass(Unknown Source)
at sun.misc.Launcher$AppClassLoader.loadClass(Unknown Source)
at java.lang.ClassLoader.loadClass(Unknown Source)
at java.lang.ClassLoader.loadClassInternal(Unknown Source)
... 14 more

Answer 1

It looks like testWriteV1_0Tag depends on JUnit, which isn’t in your classpath. Either change your code so it’s not using JUnit (and not depending on anything else which uses JUnit) or include JUnit in your path.