org.argouml.uml.reveng
Class ImportClassLoader

java.lang.Object
  java.lang.ClassLoader
      java.security.SecureClassLoader
          java.net.URLClassLoader
              org.argouml.uml.reveng.ImportClassLoader

public final class ImportClassLoader
extends java.net.URLClassLoader

Class to help users reverse engineer class information from arbitrary .jar/.class file resources, like an import classpath.

can be used as follows:

 
 try {
     ImportClassLoader loader = ImportClassLoader.getInstance();
     // add paths...
     loader.addFile(new File("/opt/lib/myjar.jar"));

     Class clazz = loader.loadClass("org.xyz.MyException");
     Object ex = clazz.newInstance();
     cat.info("loaded class ok");
 } catch(Exception e) {
     cat.warn("error loading class: "+e.toString());
 }
 
 

It should be possible to make this the system class loader, but I haven't got this to work yet:

 
 final URLClassLoader urlClassLoader = new URLClassLoader(urls, cl);
 //create a new custom class with the default classloader as its parent
 try {
     EventQueue eq = Toolkit.getDefaultToolkit().getSystemEventQueue();
     eq.invokeAndWait(new Runnable() {
         public void run() {
             Thread.currentThread().setContextClassLoader(urlClassLoader);
             // this will replace the default system class loader with
             // the new custom classloader, so that the jvm will use
             // the new custom classloader to lookup a class
         }
     });
     //...
 
 

getInstance

public static ImportClassLoader getInstance()
                                     throws java.net.MalformedURLException

Try and return the existing instance if one exists.

Returns:

the instance

Throws:

java.net.MalformedURLException - when the url is bad

getInstance

public static ImportClassLoader getInstance(java.net.URL[] urls)
                                     throws java.net.MalformedURLException

There is no default constructor for URLClassloader, so we should provide urls when creating the instance. We create a new instance in this method.

Parameters:

urls - the URLs

Returns:

the instance of this class

Throws:

java.net.MalformedURLException - when the URL is bad

addFile

public void addFile(java.io.File f)
             throws java.net.MalformedURLException

Parameters:

f - the file to be added

Throws:

java.net.MalformedURLException - when the URL is bad

removeFile

public void removeFile(java.io.File f)

Remove the given file. But we can't remove the last file.

Parameters:

f - the file to be removed

setPath

public void setPath(java.lang.String path)

Add the file for which a path is given.

Parameters:

path - the path in String format

getURLs

public static java.net.URL[] getURLs(java.lang.String path)

Add the files for which the paths are given, and return in URL format.

Parameters:

path - the paths in String format

Returns:

the URLs

setPath

public void setPath(java.lang.Object[] paths)

Parameters:

paths - the paths to the files to be added

loadUserPath

public void loadUserPath()

Get the user-configured path.

saveUserPath

public void saveUserPath()

Store the user-configured path.

toString

public java.lang.String toString()

Overrides:

toString in class java.lang.Object