spring DecoratingClassLoader 源码

spring DecoratingClassLoader 代码

文件路径：/spring-core/src/main/java/org/springframework/core/DecoratingClassLoader.java

/*
 * Copyright 2002-2017 the original author or authors.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      https://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.springframework.core;

import java.util.Collections;
import java.util.Set;
import java.util.concurrent.ConcurrentHashMap;

import org.springframework.lang.Nullable;
import org.springframework.util.Assert;

/**
 * Base class for decorating ClassLoaders such as {@link OverridingClassLoader}
 * and {@link org.springframework.instrument.classloading.ShadowingClassLoader},
 * providing common handling of excluded packages and classes.
 *
 * @author Juergen Hoeller
 * @author Rod Johnson
 * @since 2.5.2
 */
public abstract class DecoratingClassLoader extends ClassLoader {

	static {
		ClassLoader.registerAsParallelCapable();
	}


	private final Set<String> excludedPackages = Collections.newSetFromMap(new ConcurrentHashMap<>(8));

	private final Set<String> excludedClasses = Collections.newSetFromMap(new ConcurrentHashMap<>(8));


	/**
	 * Create a new DecoratingClassLoader with no parent ClassLoader.
	 */
	public DecoratingClassLoader() {
	}

	/**
	 * Create a new DecoratingClassLoader using the given parent ClassLoader
	 * for delegation.
	 */
	public DecoratingClassLoader(@Nullable ClassLoader parent) {
		super(parent);
	}


	/**
	 * Add a package name to exclude from decoration (e.g. overriding).
	 * <p>Any class whose fully-qualified name starts with the name registered
	 * here will be handled by the parent ClassLoader in the usual fashion.
	 * @param packageName the package name to exclude
	 */
	public void excludePackage(String packageName) {
		Assert.notNull(packageName, "Package name must not be null");
		this.excludedPackages.add(packageName);
	}

	/**
	 * Add a class name to exclude from decoration (e.g. overriding).
	 * <p>Any class name registered here will be handled by the parent
	 * ClassLoader in the usual fashion.
	 * @param className the class name to exclude
	 */
	public void excludeClass(String className) {
		Assert.notNull(className, "Class name must not be null");
		this.excludedClasses.add(className);
	}

	/**
	 * Determine whether the specified class is excluded from decoration
	 * by this class loader.
	 * <p>The default implementation checks against excluded packages and classes.
	 * @param className the class name to check
	 * @return whether the specified class is eligible
	 * @see #excludePackage
	 * @see #excludeClass
	 */
	protected boolean isExcluded(String className) {
		if (this.excludedClasses.contains(className)) {
			return true;
		}
		for (String packageName : this.excludedPackages) {
			if (className.startsWith(packageName)) {
				return true;
			}
		}
		return false;
	}

}

相关信息

spring 源码目录

相关文章

spring AliasRegistry 源码

spring AttributeAccessor 源码

spring AttributeAccessorSupport 源码

spring BridgeMethodResolver 源码

spring CollectionFactory 源码

spring ConfigurableObjectInputStream 源码

spring Constants 源码

spring Conventions 源码

spring CoroutinesUtils 源码

spring DecoratingProxy 源码