io.vertx.core.impl.IsolatingClassLoader.java Source code

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Here is the source code for io.vertx.core.impl.IsolatingClassLoader.java

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/*
 * Copyright (c) 2011-2014 The original author or authors
 * ------------------------------------------------------
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * and Apache License v2.0 which accompanies this distribution.
 *
 *     The Eclipse Public License is available at
 *     http://www.eclipse.org/legal/epl-v10.html
 *
 *     The Apache License v2.0 is available at
 *     http://www.opensource.org/licenses/apache2.0.php
 *
 * You may elect to redistribute this code under either of these licenses.
 */

package io.vertx.core.impl;

import java.net.URL;
import java.net.URLClassLoader;

/**
 * Before delegating to the parent, this classloader attempts to load the class first
 * (opposite of normal delegation model).
 * This allows multiple versions of the same class to be loaded by different classloaders which allows
 * us to isolate verticles so they can't easily interact
 *
 * @author <a href="http://tfox.org">Tim Fox</a>
 */
public class IsolatingClassLoader extends URLClassLoader {

    IsolatingClassLoader(URL[] urls, ClassLoader parent) {
        super(urls, parent);
    }

    @Override
    protected Class<?> loadClass(String name, boolean resolve) throws ClassNotFoundException {
        synchronized (getClassLoadingLock(name)) {
            Class<?> c = findLoadedClass(name);
            if (c == null) {
                // We don't want to load Vert.x (or Vert.x dependency) classes from an isolating loader
                if (isVertxOrSystemClass(name)) {
                    try {
                        c = super.loadClass(name, false);
                    } catch (ClassNotFoundException e) {
                        // Fall through
                    }
                }
                if (c == null) {
                    // Try and load with this classloader
                    try {
                        c = findClass(name);
                    } catch (ClassNotFoundException e) {
                        // Now try with parent
                        c = super.loadClass(name, false);
                    }
                }
            }
            if (resolve) {
                resolveClass(c);
            }
            return c;
        }
    }

    private boolean isVertxOrSystemClass(String name) {
        return name.startsWith("java.") || name.startsWith("javax.") || name.startsWith("com.sun.")
                || name.startsWith("io.vertx.core") || name.startsWith("com.hazelcast")
                || name.startsWith("io.netty.") || name.startsWith("com.fasterxml.jackson");
    }
}