Java tutorial
/* * Copyright 2012 The Netty Project * * The Netty Project licenses this file to you 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: * * http://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 io.netty.handler.codec.serialization; import io.netty.util.internal.PlatformDependent; import java.lang.ref.Reference; import java.util.HashMap; public final class ClassResolvers { /** * cache disabled * @param classLoader - specific classLoader to use, or null if you want to revert to default * @return new instance of class resolver */ public static ClassResolver cacheDisabled(ClassLoader classLoader) { return new ClassLoaderClassResolver(defaultClassLoader(classLoader)); } /** * non-aggressive non-concurrent cache * good for non-shared default cache * * @param classLoader - specific classLoader to use, or null if you want to revert to default * @return new instance of class resolver */ public static ClassResolver weakCachingResolver(ClassLoader classLoader) { return new CachingClassResolver(new ClassLoaderClassResolver(defaultClassLoader(classLoader)), new WeakReferenceMap<String, Class<?>>(new HashMap<String, Reference<Class<?>>>())); } /** * aggressive non-concurrent cache * good for non-shared cache, when we're not worried about class unloading * * @param classLoader - specific classLoader to use, or null if you want to revert to default * @return new instance of class resolver */ public static ClassResolver softCachingResolver(ClassLoader classLoader) { return new CachingClassResolver(new ClassLoaderClassResolver(defaultClassLoader(classLoader)), new SoftReferenceMap<String, Class<?>>(new HashMap<String, Reference<Class<?>>>())); } /** * non-aggressive concurrent cache * good for shared cache, when we're worried about class unloading * * @param classLoader - specific classLoader to use, or null if you want to revert to default * @return new instance of class resolver */ public static ClassResolver weakCachingConcurrentResolver(ClassLoader classLoader) { return new CachingClassResolver(new ClassLoaderClassResolver(defaultClassLoader(classLoader)), new WeakReferenceMap<String, Class<?>>( PlatformDependent.<String, Reference<Class<?>>>newConcurrentHashMap())); } /** * aggressive concurrent cache * good for shared cache, when we're not worried about class unloading * * @param classLoader - specific classLoader to use, or null if you want to revert to default * @return new instance of class resolver */ public static ClassResolver softCachingConcurrentResolver(ClassLoader classLoader) { return new CachingClassResolver(new ClassLoaderClassResolver(defaultClassLoader(classLoader)), new SoftReferenceMap<String, Class<?>>( PlatformDependent.<String, Reference<Class<?>>>newConcurrentHashMap())); } static ClassLoader defaultClassLoader(ClassLoader classLoader) { if (classLoader != null) { return classLoader; } final ClassLoader contextClassLoader = PlatformDependent.getContextClassLoader(); if (contextClassLoader != null) { return contextClassLoader; } return PlatformDependent.getClassLoader(ClassResolvers.class); } private ClassResolvers() { // Unused } }