回顾SpringAOP中的Advice

梦里梦外; 2022-10-27 05:21 227阅读 0赞

##  ##

## 一 概述 ##

@Before：前置通知

@After ：后置通知，方法执行完之后

@AfterReturning：返回通知，完成执行之后

@AfterThrowing：异常通知，抛出异常之后

@Around：环绕通知

## 二 Advice应用实例 ##

**通过环绕通知获取方法执行时间**

@Component
    @Aspect
    public class RepositoryAspect {
    
        @Pointcut("execution(* com.repository..*(..))")
        private void crud() {
        }
    
        //环绕通知
        @Around("crud()")
        public Object logPerformance(ProceedingJoinPoint joinPoint) throws Throwable {
            long startTimes = System.currentTimeMillis();
            Object result = null;
            String name = "-";
            try {
                name = joinPoint.getSignature().toShortString();
                result = joinPoint.proceed();
                return result;
            } catch (Throwable t) {
                throw t;
            } finally {
                long duration = System.currentTimeMillis() - startTimes;
                StringBuilder stringBuilder = new StringBuilder();
                stringBuilder.append(name);
                System.out.println(stringBuilder+"执行时间为"+duration)
            }
        }
    }

public class AbstractAspect {
    	protected ThreadLocal<Map<String, Object>> threadLocal = new ThreadLocal<>();
    
    	protected ThreadLocal<Map<String, Object>> getThreadLocal(){
    		if (threadLocal.get() == null){
    			threadLocal.set(new HashMap<>());
    		}
    		return threadLocal;
    	}
    }

@Component
    @Aspect
    public class ControllerAspect extends AbstractAspect {
    
        //对于controller包下所有类和方法进行获取，除被注解NoHealth标注的类除外。
        @Pointcut("execution(* com.controller..*(..))&&!@annotation(NoHealth)")
        private void controllerPointCut() {
        }
    
        //在方法执行之前对参数进行处理 
        @Before(value = "controllerPointCut()")
        public void doBefore(JoinPoint joinPoint) {
            try {
                getThreadLocal().get().put(joinPoint.getSignature().toString(), System.currentTimeMillis());
                Object[] args = joinPoint.getArgs();
                MethodSignature methodSignature = (MethodSignature) joinPoint.getSignature();
                String[] parameterNamesArray = methodSignature.getParameterNames();
                int i = 0;
                List<String> argsList = new ArrayList<>();
                if (!ObjectUtils.isEmpty(args)) {
                    for (Object object : args) {
                        if (ObjectUtils.isEmpty(object)
                                || (object instanceof BeanPropertyBindingResult)
                                || (object instanceof HttpServletResponse)
                                || (object instanceof Boolean)
                                || (object instanceof String)
                                || (object instanceof Integer)) {
    
                            if ((object instanceof Boolean) || (object instanceof String) || (object instanceof Integer)) {
                                StringBuilder stringBuilder = new StringBuilder();
                                stringBuilder.append("{\"");
                                stringBuilder.append(parameterNamesArray[i]);
                                stringBuilder.append("\":\"");
                                stringBuilder.append(object);
                                stringBuilder.append("\"}");
                                argsList.add(JSONObject.fromObject(String.valueOf(stringBuilder)).toString());
                            }
                            i++;
                            continue;//跳出当前循环，且不执行此语句后面的语句！
                        }
    
                        if (!(object instanceof HttpServletRequest)) {
                            argsList.add(JSONObject.fromObject(object).toString());
                        } else {
                            HttpServletRequest request = (HttpServletRequest) object;
                            Enumeration<String> parameterNames = request.getParameterNames();
                            Map<String, String> argsMap = new HashMap<>();
                            while (parameterNames.hasMoreElements()) {
                                String elementName = parameterNames.nextElement();
                                argsMap.put(elementName, request.getAttribute(elementName).toString());
                            }
                            if (!ObjectUtils.isEmpty(argsMap)) {
                                argsList.add(JSONObject.fromObject(argsMap).toString());
                            }
                        }
                        i++;
                    }
                }
                StringBuilder stringBuilder = new StringBuilder();
                stringBuilder.append(JSONArray.fromObject(argsList));
            } catch (Exception e) {
              
            }
        }
    
        //对方法执行之后的返回值进行某种操作
        @AfterReturning(value = "controllerPointCut()", returning = "response")
        public void responseLog(JoinPoint joinPoint, Object response) {
            try {
                if (response == null) {
                    response = new Object();
                }
                long duration = System.currentTimeMillis() - (Long) threadLocal.get().get(joinPoint.getSignature().toString());
                StringBuilder stringB uilder = new StringBuilder();
                stringBuilder.append(JSONObject.fromObject(response));
            } catch (Exception e) {
               
            }
        }
    
        //对方法抛出的异常进行操作
        @AfterThrowing(value = "controllerPointCut()", throwing = "e")
        public void exceptionLog(Exception e) {
    
        }
    }

**根据这些实例就可以参照写一些简单的SpringAOP实例了！**