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1. 本章须要实现的内容
- 实现 AspectListExecutor 类的编写
- 实现 AspectWeaver 类的编写
- 实现 PointcutLocator 类的编写
- 实现 ProxyCreator 类的编写
2. 实现 PointcutLocator 类的编写
2.1 须要实现的代码如下：
package com.wuyiccc.helloframework.aop;
import org.aspectj.weaver.tools.PointcutExpression;
import org.aspectj.weaver.tools.PointcutParser;
import org.aspectj.weaver.tools.ShadowMatch;
import java.lang.reflect.Method;
/**
* @author wuyiccc
* @date 2020/7/14 9:03
* 岂曰无衣，与子同袍~
*/
public class PointcutLocator {
/**
* Pointcut 解析器，间接给它赋值上 Aspectj 的所有表达式，以便反对对泛滥表达式的解析
*/
private PointcutParser pointcutParser = PointcutParser.getPointcutParserSupportingSpecifiedPrimitivesAndUsingContextClassloaderForResolution(PointcutParser.getAllSupportedPointcutPrimitives());
/**
* 表达式解析器
*/
private PointcutExpression pointcutExpression;
public PointcutLocator(String expression) {this.pointcutExpression = pointcutParser.parsePointcutExpression(expression);
}
/**
* 判断传入的 Class 对象是否是 Aspect 的指标代理类，即匹配 Pointcut 表达式 (初筛)
*
* @param targetClass 指标类
* @return 是否匹配
*/
public boolean roughMatches(Class<?> targetClass) {return pointcutExpression.couldMatchJoinPointsInType(targetClass); // 只能校验 within，对于 execution,call,get,set 等无奈校验的表达式，间接返回 true
}
/**
* 判断传入的 Method 对象是否是 Aspect 的指标代理办法，即匹配 Pointcut 表达式 (精筛)
* @param method
* @return
*/
public boolean accurateMatches(Method method) {ShadowMatch shadowMatch = pointcutExpression.matchesMethodExecution(method);
if (shadowMatch.alwaysMatches()) {return true;}
return false;
}
}
2.2 PointcutLocator 类相干办法解说:
3. 实现 AspectListExecutor 类的编写
3.1 须要实现的代码如下:
package com.wuyiccc.helloframework.aop;
import com.wuyiccc.helloframework.aop.aspect.AspectInfo;
import com.wuyiccc.helloframework.util.ValidationUtil;
import lombok.Getter;
import net.sf.cglib.proxy.MethodInterceptor;
import net.sf.cglib.proxy.MethodProxy;
import java.lang.reflect.Method;
import java.util.Collections;
import java.util.Comparator;
import java.util.Iterator;
import java.util.List;
/**
* @author wuyiccc
* @date 2020/7/14 9:03
* 岂曰无衣，与子同袍~
*/
public class AspectListExecutor implements MethodInterceptor {
private Class<?> targetClass;
@Getter
private List<AspectInfo> sortedAspectInfoList;
public AspectListExecutor(Class<?> targetClass, List<AspectInfo> sortedAspectInfoList) {
this.targetClass = targetClass;
this.sortedAspectInfoList = sortAspectInfoList(sortedAspectInfoList);
}
/**
* 依照 order 的值进行升序排序，确保 Order 值小的 aspect 先被织入
*
* @param aspectInfoList
* @return
*/
private List<AspectInfo> sortAspectInfoList(List<AspectInfo> aspectInfoList) {
// 升序排列
Collections.sort(aspectInfoList, new Comparator<AspectInfo>() {
@Override
public int compare(AspectInfo o1, AspectInfo o2) {return o1.getOrderIndex() - o2.getOrderIndex();}
});
return aspectInfoList;
}
@Override
public Object intercept(Object proxy, Method method, Object[] args, MethodProxy methodProxy) throws Throwable {
Object returnValue = null;
collectAccurateMatchedAspectList(method);
if (ValidationUtil.isEmpty(sortedAspectInfoList)) {return methodProxy.invokeSuper(proxy, args);
}
// 1. 依照 order 的程序升序执行完所有 Aspect 的 before 办法
invokeBeforeAdvices(method, args);
try {
// 2. 执行被代理类的办法
returnValue = methodProxy.invokeSuper(proxy, args);
// 3. 如果被代理办法失常返回，则依照 order 的程序降序执行完所有 Aspect 的 afterReturning 办法
invokeAfterReturningAdvices(method, args, returnValue);
} catch (Exception e) {
// 4. 如果被代理办法抛出异样，则依照 order 的程序降序执行完所有 Aspect 的 afterThrowing 办法
invokeAfterThrowingAdvices(method, args, e);
}
return returnValue;
}
private void collectAccurateMatchedAspectList(Method method) {if (ValidationUtil.isEmpty(sortedAspectInfoList)) {return;}
Iterator<AspectInfo> it = sortedAspectInfoList.iterator();
while (it.hasNext()) {AspectInfo aspectInfo = it.next();
if (!aspectInfo.getPointcutLocator().accurateMatches(method)) {it.remove(); // 须要用 Iterator 自带的 remove，不能用 sortedAspectInfoList 的 remove，否则就会呈现并发批改异样
}
}
}
private void invokeAfterThrowingAdvices(Method method, Object[] args, Exception e) throws Throwable {for (int i = sortedAspectInfoList.size() - 1; i >= 0; i--) {sortedAspectInfoList.get(i).getAspectObject().afterThrowing(targetClass, method, args, e);
}
}
private void invokeAfterReturningAdvices(Method method, Object[] args, Object returnValue) throws Throwable {for (int i = sortedAspectInfoList.size() - 1; i >= 0; i--) {sortedAspectInfoList.get(i).getAspectObject().afterReturning(targetClass, method, args, returnValue);
}
}
private void invokeBeforeAdvices(Method method, Object[] args) throws Throwable {for (AspectInfo aspectInfo : sortedAspectInfoList) {aspectInfo.getAspectObject().before(targetClass, method, args);
}
}
}
3.2 AspectListExecutor 类相干办法解说：
4. 实现 ProxyCreator 类的编写
4.1 须要实现的代码及解说如下：
5. 实现 AspectWeaver 类的编写
5.1 须要实现的代码如下：
package org.myframework.aop;
import org.myframework.aop.annotation.Aspect;
import org.myframework.aop.annotation.Order;
import org.myframework.aop.aspect.AspectInfo;
import org.myframework.aop.aspect.DefaultAspect;
import org.myframework.core.BeanContainer;
import org.myframework.util.ValidationUtil;
import java.util.ArrayList;
import java.util.List;
import java.util.Set;
/**
* @author wuyiccc
* @date 2020/6/16 8:49
* 岂曰无衣，与子同袍~
*/
public class AspectWeaver {
private BeanContainer beanContainer;
public AspectWeaver() {beanContainer = BeanContainer.getInstance();
}
public void doAop() {
// 1. 获取所有的切面类
Set<Class<?>> aspectSet = beanContainer.getClassesByAnnotation(Aspect.class);
if (ValidationUtil.isEmpty(aspectSet)) {return;}
// 2. 拼装 AspectInfoList
List<AspectInfo> aspectInfoList = packAspectInfoList(aspectSet);
// 3. 遍历容器里的类
Set<Class<?>> classSet = beanContainer.getClasses();
for (Class<?> targetClass : classSet) {
// 排除 AspectClass 本身
if (targetClass.isAnnotationPresent(Aspect.class)) {continue;}
// 4. 粗筛符和条件的 Aspect
List<AspectInfo> roughMatchedAspectList = collectRoughMatchAspectListForSpecificClass(aspectInfoList, targetClass);
// 5. 尝试进行 Aspect 织入
wrapIfNecessary(roughMatchedAspectList, targetClass);
}
}
private void wrapIfNecessary(List<AspectInfo> roughMatchedAspectList, Class<?> targetClass) {if (ValidationUtil.isEmpty(roughMatchedAspectList)) {return;}
// 创立动静代理对象
AspectListExecutor aspectListExecutor = new AspectListExecutor(targetClass, roughMatchedAspectList);
Object proxyBean = ProxyCreator.createProxy(targetClass, aspectListExecutor);
beanContainer.addBean(targetClass, proxyBean);
}
private List<AspectInfo> collectRoughMatchAspectListForSpecificClass(List<AspectInfo> aspectInfoList, Class<?> targetClass) {List<AspectInfo> roughMatchedAspectList = new ArrayList<>();
for (AspectInfo aspectInfo : aspectInfoList) {
// 粗筛
if (aspectInfo.getPointcutLocator().roughMatches(targetClass)) {roughMatchedAspectList.add(aspectInfo);
}
}
return roughMatchedAspectList;
}
private List<AspectInfo> packAspectInfoList(Set<Class<?>> aspectSet) {List<AspectInfo> aspectInfoList = new ArrayList<>();
for (Class<?> aspectClass : aspectSet) {if (verifyAspect(aspectClass)) {Order orderTag = aspectClass.getAnnotation(Order.class);
Aspect aspectTag = aspectClass.getAnnotation(Aspect.class);
DefaultAspect defaultAspect = (DefaultAspect) beanContainer.getBean(aspectClass);
// 初始化表达式定位器
PointcutLocator pointcutLocator = new PointcutLocator(aspectTag.pointcut());
AspectInfo aspectInfo = new AspectInfo(orderTag.value(), defaultAspect, pointcutLocator);
aspectInfoList.add(aspectInfo);
} else {throw new RuntimeException("@Aspect and @Order must be added to the Aspect class, and Aspect class must extend from DefaultAspect");
}
}
return aspectInfoList;
}
// 框架中肯定要恪守给 Aspect 增加的 @Aspect 和 @Order 标签的标准，同时，必须继承自 DefaultAspect.class
private boolean verifyAspect(Class<?> aspectClass) {return aspectClass.isAnnotationPresent(Aspect.class)
&& aspectClass.isAnnotationPresent(Order.class)
&& DefaultAspect.class.isAssignableFrom(aspectClass);
}
}
5.2 AspectWeaver 类相干办法解析：
github 地址：https://github.com/wuyiccc/he…
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