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Core interpreter artifact for the ASTRA Language

There is a newer version: 1.4.2

package astra.core;

import java.util.HashMap;
import java.util.LinkedList;
import java.util.List;
import java.util.Map;

public class ASTRAClassLoader {
	private static ASTRAClassLoader defaultClassLoader = new ASTRAClassLoader();

	public static ASTRAClassLoader getDefaultClassLoader() {
		return defaultClassLoader;
	}

	private List loaders = new LinkedList();
	private Map classes = new HashMap();

	{
		loaders.add(ClassLoader.getSystemClassLoader());
	}

	public void registerClassLoader(ClassLoader loader) {
		loaders.add(loader);
	}

	/**
	 * Loads the corrsponding astra class if it is not already loaded. if it is
	 * loaded, then it returns the current reference.
	 * 
	 * @param url the url of the class to be loaded
	 * @return an {@link ASTRAClass} object representing the class associated with
	 *         the url
	 * @throws ASTRAClassNotFoundException generated if the class does not exist
	 */
	public ASTRAClass loadClass(String url) throws ASTRAClassNotFoundException {
		ASTRAClass clazz = classes.get(url);
		if (clazz == null) {
			Class c = null;
			for (ClassLoader loader : loaders) {
				c = doLoadClass(loader, url);
				if (c != null)
					break;
			}
			if (c != null) {
				try {
					clazz = (ASTRAClass) c.getDeclaredConstructor(new Class[0]).newInstance(new Object[0]);
				} catch (Exception e) {
					throw new ASTRAClassNotFoundException("Could not load ASTRA class: " + url,e);
				}
			} else {
				throw new ASTRAClassNotFoundException("Could not find ASTRA class: " + url);
			}
			classes.put(url, clazz);
		}
			
		return clazz;
	}
	
	public ASTRAClass loadClass(Class cls) throws ASTRAClassNotFoundException {
		ASTRAClass clazz = classes.get(cls.getCanonicalName());
		if (clazz == null) {
			try {
				clazz = (ASTRAClass) cls.getDeclaredConstructor(new Class[0]).newInstance(new Object[0]);
			} catch (Exception e) {
				throw new ASTRAClassNotFoundException("Could not load ASTRA class: " + cls.getCanonicalName(),e);
			}
			classes.put(cls.getCanonicalName(), clazz);
		}
			
		return clazz;
	}

	private Class doLoadClass(ClassLoader loader, String url) {
		try {
			return loader.loadClass(url);
		} catch (ClassNotFoundException e) {
			e.printStackTrace();
		}
		return null;
	}
}