org.aspectj.weaver.bcel.ExtensibleURLClassLoader Maven / Gradle / Ivy

Show more of this group Show more artifacts with this name
Show all versions of aspectjtools Show documentation

AspectJ tools most notably contains the AspectJ compiler (AJC). AJC applies aspects to Java classes during compilation, fully replacing Javac for plain Java classes and also compiling native AspectJ or annotation-based @AspectJ syntax. Furthermore, AJC can weave aspects into existing class files in a post-compile binary weaving step. This library is a superset of AspectJ weaver and hence also of AspectJ runtime.

There is a newer version: 1.9.22.1

Show newest version

/* *******************************************************************
 * Copyright (c) 2004 IBM Corporation
 * All rights reserved.
 * This program and the accompanying materials are made available
 * under the terms of the Eclipse Public License v 2.0
 * which accompanies this distribution and is available at
 * https://www.eclipse.org/org/documents/epl-2.0/EPL-2.0.txt
 *
 * Contributors:
 *     Matthew Webster, Adrian Colyer,
 *     Martin Lippert     initial implementation
 *     Andy Clement
 *     Roy Varghese - Bug 473555
 * ******************************************************************/

package org.aspectj.weaver.bcel;

import java.io.IOException;
import java.net.URL;
import java.net.URLClassLoader;
import java.security.CodeSource;

import org.aspectj.util.FileUtil;
import org.aspectj.weaver.BCException;
import org.aspectj.weaver.UnresolvedType;

public abstract class ExtensibleURLClassLoader extends URLClassLoader {

	private ClassPathManager classPath;

	public ExtensibleURLClassLoader(URL[] urls, ClassLoader parent) {
		super(urls, parent);

		// System.err.println("? ExtensibleURLClassLoader.() path=" + WeavingAdaptor.makeClasspath(urls));
		try {
			classPath = new ClassPathManager(FileUtil.makeClasspath(urls), null);
		} catch (ExceptionInInitializerError ex) {
			ex.printStackTrace(System.out);
			throw ex;
		}
	}

	protected void addURL(URL url) {
		super.addURL(url); // amc - this call was missing and is needed in
		// WeavingURLClassLoader chains
		classPath.addPath(url.getPath(), null);
	}

	protected Class findClass(String name) throws ClassNotFoundException {
		// System.err.println("? ExtensibleURLClassLoader.findClass(" + name + ")");
		try {
			byte[] bytes = getBytes(name);
			if (bytes != null) {
				return defineClass(name, bytes);
			} else {
				throw new ClassNotFoundException(name);
			}
		} catch (IOException ex) {
			throw new ClassNotFoundException(name, ex);
		}
	}

	protected Class defineClass(String name, byte[] b, CodeSource cs) throws IOException {
		// System.err.println("? ExtensibleURLClassLoader.defineClass(" + name + ",[" + b.length + "])");
		return defineClass(name, b, 0, b.length, cs);
	}

	protected byte[] getBytes(String name) throws IOException {
		byte[] b = null;
		UnresolvedType unresolvedType = null;
		try {
			unresolvedType = UnresolvedType.forName(name);
		} catch (BCException bce) {
			if (!bce.getMessage().contains("nameToSignature")) {
				bce.printStackTrace(System.err);
			}
			return null;
		}
		ClassPathManager.ClassFile classFile = classPath.find(unresolvedType);
		if (classFile != null) {
			try {
				b = FileUtil.readAsByteArray(classFile.getInputStream());
			} finally {
				classFile.close();
			}
		}
		return b;
	}

	private Class defineClass(String name, byte[] bytes /* ClassPathManager.ClassFile classFile */) throws IOException {
		String packageName = getPackageName(name);
		if (packageName != null) {
			Package pakkage = getPackage(packageName);
			if (pakkage == null) {
				definePackage(packageName, null, null, null, null, null, null, null);
			}
		}

		return defineClass(name, bytes, null);
	}

	private String getPackageName(String className) {
		int offset = className.lastIndexOf('.');
		return (offset == -1) ? null : className.substring(0, offset);
	}

	@Override
	public void close() throws IOException {
		super.close();
		classPath.closeArchives();
	}

}