com.jfinal.ext.proxy.CglibProxyFactory Maven / Gradle / Ivy

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/**
 * Copyright (c) 2011-2019, James Zhan 詹波 ([email protected]).
 *
 * 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
 *
 *      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 com.jfinal.ext.proxy;

import java.lang.reflect.Method;
import java.util.Map;
import java.util.Objects;
import com.jfinal.aop.Interceptor;
import com.jfinal.kit.HashKit;
import com.jfinal.kit.SyncWriteMap;
import com.jfinal.proxy.ProxyFactory;

/**
 * CglibProxyFactory 用于扩展 cglib 的代理模式，默认不使用
 * 
 *  * 配置方法：
 * public void configConstant(Constants me) {
 *     ProxyManager.me().setProxyFactory(new CglibProxyFactory());
 * }
 * 
 */
public class CglibProxyFactory extends ProxyFactory {
	
	@SuppressWarnings("unchecked")
	public  T get(Class target) {
		return (T)net.sf.cglib.proxy.Enhancer.create(target, new CglibCallback());
	}
	
	static class IntersCache {
		private static final Map cache = new SyncWriteMap<>(2048, 0.25F);
		
		public static void put(MethodKey methodKey, Interceptor[] inters) {
			Objects.requireNonNull(methodKey, "methodKey can not be null");
			Objects.requireNonNull(inters, "inters can not be null");
			
			cache.putIfAbsent(methodKey, inters);
		}
		
		public static Interceptor[] get(MethodKey methodKey) {
			return cache.get(methodKey);
		}
		
		public static MethodKey getMethodKey(Class target, Method method) {
			long paraHash = HashKit.FNV_OFFSET_BASIS_64;
			Class[] paraTypes = method.getParameterTypes();
			for (Class pt : paraTypes) {
				paraHash ^= pt.getName().hashCode();
				paraHash *= HashKit.FNV_PRIME_64;
			}
			
			return new MethodKey(target.getName().hashCode(), method.getName().hashCode(), paraHash);
		}
	}
	
	static class MethodKey {
		final int classHash;
		final int methodHash;
		final long paraHash;
		
		MethodKey(int classHash, int methodHash, long paraHash) {
			this.classHash = classHash;
			this.methodHash = methodHash;
			this.paraHash = paraHash;
		}
		
		public int hashCode() {
			return classHash ^ methodHash ^ ((int)paraHash);
		}
		
		/**
		 * 通过比较三部分 hash 值，避免超大规模场景下可能的 key 值碰撞
		 * 
		 * 不必判断 if (methodKey instanceof MethodKey)，因为所有 key 类型必须要相同
		 * 不必判断 if (this == methodKey)，因为每次用于取值的 methodKey 都是新建的
		 */
		public boolean equals(Object methodKey) {
			MethodKey mk = (MethodKey)methodKey;
			return classHash == mk.classHash && methodHash == mk.methodHash && paraHash == mk.paraHash;
		}
		
		public String toString() {
			return "classHash = " + classHash + "\nmethodHash = " + methodHash + "\nparaHash = " + paraHash;
		}
	}
}