Setting classpath within java application

Question

Hi
Sorry if this question has already been asked, I've searched for it but couldn't find it.
I've written a class (see below) that when given a directory will add all of the jar files to the classpath.
The classpath is updated to include all of the jar files but if I try to use a class within one of these jar files then an exception is generated stating that the class can't be found.
Can anyone help me with this problem? I thought that I would only need to update the classpath.
Thanks,
Rob
public class Jar {
     public static void addJarsToClasspath(String root) {
          File f = new File(root);
          if (f.exists()) {
               File[] jars = f.listFiles(new FilenameFilter(){
                    public boolean accept(File dir, String file) {
                         return ((String)dir.getName()+file).endsWith(".jar");
               String classpath = System.getProperty("java.class.path");
               for (int i=0; i<jars.length; i++) {
                         classpath = classpath.concat(":"+root+"/"+jars.getName());
               System.setProperty("java.class.path",classpath);
               System.out.println(System.getProperty("java.class.path"));

Answer 1

You can do this with batch files in Windows NT/2000:
1) create a batch file called "setcp.bat" containing the following:
for %%i in (C:\myPath\*.jar) do call appendcp.bat %%i
2) create another batch file called "appendcp.bat" containing the following:
set CLASSPATH=%CLASSPATH%;%1
Now you can run setcp.bat and it will add all JAR files in C:\myPath to your CLASSPATH.
Jesper