本文主要讲解SpringAOP的实现方式有哪些, 业务代码场景来自于上一篇文章 : 《基于 Spring AOP 实现的 通用实验组件 AB实验/AB测试》, 对该业务感兴趣的同学可以看看哈.
使用 @Aspect 注解(或者XML配置)
代码语言：javascript复制/**
* 实验能力切面
*/
@Slf4j
@Aspect
@Component
public class ExperimentAspect {
/**
* 定义切点
*/
@Pointcut("@within(com.eden.springbootwebdemo.web.experiment.Experimentable)")
public void pointCut() {
}
/**
* @param proceedingJoinPoint 被织入的目标
* @return 方法执行结果
*/
@Around("pointCut()")
public Object doAround(ProceedingJoinPoint proceedingJoinPoint) throws Throwable {
return ExperimentInterceptor.experimentInvoke(proceedingJoinPoint.proceed(), proceedingJoinPoint.getTarget(), proceedingJoinPoint.getSignature().getName());
}
}实现 MethodInterceptor 接口
为什么可以通过这种方式实现AOP ? 如果你也有这样的问题, 挺好的, 一起学习. 这个涉及到 Spring Bean 加载过程, 流程比较复杂, 后面会做专题分享
代码语言：javascript复制@Slf4j
public class ExperimentInterceptor implements MethodInterceptor {
private static final ExperimentParamMetedata nonExperimentableMetedata = new ExperimentParamMetedata();
public Object invoke(MethodInvocation methodInvocation) throws Throwable {
return ExperimentInterceptor.experimentInvoke(methodInvocation.proceed(), methodInvocation.getThis(), methodInvocation.getMethod().getName());
}
public static Object experimentInvoke(Object originalValue, Object target, String targetMethodName) {
ExperimentParamMetedata experimentParamMetedata;
try {
experimentParamMetedata = ExperimentInterceptor.inExperiment(target, targetMethodName, ExperimentSettingDemo.EXPERIMENT_SETTINGMAP);
} catch (RuntimeException exception) {
log.error("ExperimentAspect-未知异常", exception);
return originalValue;
}
if (experimentParamMetedata.isExperimentable()) {
try {
return queryExperimentValue(experimentParamMetedata.getPropertyName(), experimentParamMetedata.getPropertyTypeClass());
} catch (NoSuchMethodException | InvocationTargetException | InstantiationException | IllegalAccessException e) {
log.error("ExperimentAspect-结果解析异常", e);
throw new RuntimeException("ExperimentAspect-结果解析异常", e);
}
}
return originalValue;
}
/**
* 判断当前目标方法是不是需要进行实验
*
* @param experimentSettingMap 实验配置
* @return 方法可实验性校验结果
*/
private static ExperimentParamMetedata inExperiment(Object target, String targetMethodName, Map<String, List<String>> experimentSettingMap) {
Class<?> targetClass = AopUtils.isAopProxy(target) ? AopUtils.getTargetClass(target) : target.getClass();
// 是否在实验中
NonExperimentable nonExperimentable = AnnotationUtils.findAnnotation(targetClass, NonExperimentable.class);
if (null != nonExperimentable) {
return nonExperimentableMetedata;
}
// 实验配置是否有数据
if (null == experimentSettingMap || experimentSettingMap.isEmpty()) {
return nonExperimentableMetedata;
}
BeanInfo targetBeanInfo;
try {
targetBeanInfo = Introspector.getBeanInfo(target.getClass());
} catch (IntrospectionException e) {
throw new RuntimeException(e);
}
Optional<PropertyDescriptor> propertyDescriptorOptional = Arrays.stream(targetBeanInfo.getPropertyDescriptors())
.filter(item -> item.getReadMethod().getName().equals(targetMethodName)).findFirst();
if (propertyDescriptorOptional.isPresent()) {
PropertyDescriptor propertyDescriptor = propertyDescriptorOptional.get();
String propertyName = propertyDescriptor.getName();
Field propertyField = ReflectionUtils.findField(targetClass, propertyName);
if (propertyField != null) {
Value valueAnnotation = propertyField.getDeclaredAnnotation(Value.class);
if (null != valueAnnotation && ExperimentSettingDemo.EXPERIMENT_PROPERTY_NAME.contains(propertyName)) {
ExperimentParamMetedata experimentParamMetedata = new ExperimentParamMetedata();
experimentParamMetedata.setExperimentable(true);
experimentParamMetedata.setPropertyTypeClass(propertyDescriptor.getPropertyType());
experimentParamMetedata.setPropertyName(propertyName);
return experimentParamMetedata;
}
}
}
return nonExperimentableMetedata;
}
/**
* 查询属性对应的实验值
*
* @param experimentPropertyName 实验属性名称
* @param propertyTypeClass 属性类型
* @return 实验值
*/
public static Object queryExperimentValue(String experimentPropertyName, Class<?> propertyTypeClass) throws InvocationTargetException, NoSuchMethodException, InstantiationException, IllegalAccessException {
List<String> experimentReturnStringValues = ExperimentSettingDemo.EXPERIMENT_SETTINGMAP.get(experimentPropertyName);
// 几个配置随机选一个返回
int index = RandomUtils.nextInt(0, experimentReturnStringValues.size());
return StringCastUtil.cast(experimentReturnStringValues.get(index), propertyTypeClass);
}
}扫包的实现方式有哪些
AspectJExpressionPointcut AnnotationMatchingPointcut JdkRegexpMethodPointcut
代码语言：javascript复制@Configuration
public class ExperimentInterceptorConfig {
@Bean
public DefaultPointcutAdvisor defaultPointcutAdvisor() {
ExperimentInterceptor interceptor = new ExperimentInterceptor();
AspectJExpressionPointcut pointcut = new AspectJExpressionPointcut();
pointcut.setExpression("execution(* com.eden.springbootwebdemo.service.*.*(..))");
// AnnotationMatchingPointcut pointcut = new AnnotationMatchingPointcut(HfiTrace.class, true);
// JdkRegexpMethodPointcut pointcut = new JdkRegexpMethodPointcut();
// pointcut.setPatterns("com.eden.springbootwebdemo.service.*");
DefaultPointcutAdvisor advisor = new DefaultPointcutAdvisor();
advisor.setPointcut(pointcut);
advisor.setAdvice(interceptor);
return advisor;
}
}
