java.lang.NoClassDefFoundError:

[Jon Camilleri]

I'm trying to compile my little application from the command line to check if it takes command line parameters, however, it's not compiling.

The source code originally was compiled at C:\Users\Administrator\workspace\ChopLineNumbers\bin\homenetwork\bkr\training (which is my Eclipse workspace sub directory.

    
04/07/2009  10:53    <DIR>          .
04/07/2009  10:53    <DIR>          ..
04/07/2009  10:48             2,549 ChopLineNumbers.class
02/07/2009  20:02             1,221 FileUtils.class
29/06/2009  17:56            10,219 LDAPTest.java
04/07/2009  10:52                 0 SetTest.java
04/07/2009  10:52                 0 SetTest.old
04/07/2009  10:50               138 undo.bat
               6 File(s)         14,127 bytes
               2 Dir(s)  138,326,077,440 bytes free

C:\source>java -cp . ChopLineNumbers
[b]Exception in thread "main" java.lang.NoClassDefFoundError: ChopLineNumbers (wron
g name: homenetwork/bkr/training/ChopLineNumbers)[/b]
        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)
Could not find the main class: ChopLineNumbers.  Program will exit.

1. Source code includes the class ChopLineNumbers

    
package homenetwork.bkr.training;
import java.util.Scanner;
import java.io.*;

public class ChopLineNumbers {

	
	public static void main(String[] args) throws IOException {
		
		String sourceFile = "c:\\source\\LDAPTest.java";
		String backupFile = "c:\\source\\LDAPTest.old"; //TODO Update pattern so that backupFile = <name without extension>.old
		
		/*
		 read source file as command line parameters.
		 should be written as: c:\\source\\SetTest.java
		*/
		
		for (int idx = 0; idx < args.length; idx++)
		{
			if (!(args[idx].equals(""))) 
			backupFile = args[idx]; 
		}
		
		boolean debug = true;
		
		//Write to a new file, keeping an .old copy of the original file.
		//TODO read the files as parameters and add the escape characters.
		//In the future add support for nix systems.
		try {
			FileUtils.copyFile( new File(sourceFile), new File(backupFile));
		} catch (IOException e1) {
			e1.printStackTrace();
		}
		
		//Delete sourceFile
		boolean success = (new File(sourceFile)).delete();
		if ((debug) && (!success)) System.out.println("Error deleting" + sourceFile);
		
		//Read the text file 
		Scanner sc = null;
		try {
			sc = new Scanner(new File(backupFile)).useDelimiter("\n");  //TODO replace with parameter
	
		} catch (FileNotFoundException e) {
			e.printStackTrace();
		} 
		
		File writeToFile = new File(sourceFile);
		if ((!(writeToFile.createNewFile())) && (debug)) System.out.println("ERROR: Cannot create file.");
		
		//create new source file
		BufferedWriter out = new BufferedWriter(new FileWriter(sourceFile));
		
		while (sc.hasNext())
		 {
			String line = sc.next();
			/* Any number of digits followed by Unicode 002E (".") is to be deleted.
			  	 The Unicode character 002E (".") has to be deleted as well, leaving the
			  	 characters up till the end of the line. 
			*/
			final String lineNumberPattern = "([\\d]+\\.)";  
			
			line = line.replaceFirst(lineNumberPattern, ""); //removes line number and "."
			line = line.replace(";", ";"+"\n"+"\r"); //adds a newline to make the file human readable
			
			//write to file
			if (success)
			{
				out.write(line);
			}
			
			if (debug) System.out.println(line);
		 }
		
		out.close();
	
	}
}

[Campbell Ritchie]

The problem is not with your code, but with your file structure. You should have a "training" folder, inside a "bkr" folder, inside a "homenetwork" folder, and you invoke that class from just outside the homenetwork folder with the instruction

java homenetwork.bkr.training.ChopLineNumbers

Remember that IDEs can use a different folder structure from what you get at the command line. Resources: Java™ tutorials, and recent thread about a related problem. Please note the link to older threads and look at them; similar problems come up quite frequently.

[Jon Camilleri]

Campbell Ritchie wrote:The problem is not with your code, but with your file structure. You should have a "training" folder, inside a "bkr" folder, inside a "homenetwork" folder, and you invoke that class from just outside the homenetwork folder with the instruction

java homenetwork.bkr.training.ChopLineNumbers

Remember that IDEs can use a different folder structure from what you get at the command line. Resources: Java™ tutorials, and recent thread about a related problem. Please note the link to older threads and look at them; similar problems come up quite frequently.

That's it thanks.

[Campbell Ritchie]