org.argouml.uml.reveng
Class ImportClassLoader

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

public class ImportClassLoader

extends 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 supports adding and removing Files from the import classpath. And saving and loading the path to/from the users properties file.

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
 }
 });
 //...

Nested Class Summary

Nested classes inherited from class java.lang.ClassLoader

Field Summary

private static ImportClassLoader	instance
private static Logger	LOG logger

Fields inherited from class java.net.URLClassLoader

Fields inherited from class java.security.SecureClassLoader

Fields inherited from class java.lang.ClassLoader

Constructor Summary

private

ImportClassLoader(URL[] urls)

Method Summary

void	addFile(File f)
static ImportClassLoader	getInstance() Try and return the existing instance if one exists.
static ImportClassLoader	getInstance(URL[] urls) There is no default constructor for URLClassloader, so we should provide urls when creating the instance.
static URL[]	getURLs(String path) Add the files for which the paths are given, and return in URL format.
void	loadUserPath() Get the user-configured path.
void	removeFile(File f) Remove the given file.
void	saveUserPath() Store the user-configured path.
void	setPath(Object[] paths)
void	setPath(String path) Add the file for which a path is given.
String	toString()

Methods inherited from class java.net.URLClassLoader

addURL, definePackage, findClass, findResource, findResources, getPermissions, getURLs, newInstance, newInstance

Methods inherited from class java.security.SecureClassLoader

defineClass

Methods inherited from class java.lang.ClassLoader

clearAssertionStatus, defineClass, defineClass, defineClass, definePackage, findLibrary, findLoadedClass, findSystemClass, getPackage, getPackages, getParent, getResource, getResourceAsStream, getResources, getSystemClassLoader, getSystemResource, getSystemResourceAsStream, getSystemResources, loadClass, loadClass, resolveClass, setClassAssertionStatus, setDefaultAssertionStatus, setPackageAssertionStatus, setSigners

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Field Detail

LOG

private static final Logger LOG

logger

instance

private static ImportClassLoader instance

Constructor Detail

ImportClassLoader

private ImportClassLoader(URL[] urls)

Method Detail

getInstance

public static ImportClassLoader getInstance()
                                     throws MalformedURLException

Try and return the existing instance if one exists.

Returns:

the instance

Throws:

MalformedURLException - when the url is bad

getInstance

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

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

Parameters:

urls - the URLs

Returns:

the instance of this class

Throws:

MalformedURLException - when the URL is bad

addFile

public void addFile(File f)
             throws MalformedURLException

Parameters:

f - the file to be added

Throws:

MalformedURLException - when the URL is bad

removeFile

public void removeFile(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(String path)

Add the file for which a path is given.

Parameters:

path - the path in String format

getURLs

public static URL[] getURLs(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(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 String toString()

See Also:

Object.toString()