自定义注解支持SpEL表达式（动态参数）

1.定义日志注解

@Target(ElementType.METHOD)
@Retention(RetentionPolicy.RUNTIME)
@Documented
public @interface SysLog {

    //普通的操作说明
    String value() default "";
    
    //spel表达式的操作说明
    String spelValue() default "";
}      

2.定义spel解析工具类

public class SpelUtil {

    /**
     * 用于SpEL表达式解析.
     */
    private static SpelExpressionParser parser = new SpelExpressionParser();
    /**
     * 用于获取方法参数定义名字.
     */
    private static DefaultParameterNameDiscoverer nameDiscoverer = new DefaultParameterNameDiscoverer();

    public static String generateKeyBySpEL(String spELString, ProceedingJoinPoint joinPoint) {
        // 通过joinPoint获取被注解方法
        MethodSignature methodSignature = (MethodSignature) joinPoint.getSignature();
        Method method = methodSignature.getMethod();
        // 使用spring的DefaultParameterNameDiscoverer获取方法形参名数组
        String[] paramNames = nameDiscoverer.getParameterNames(method);
        // 解析过后的Spring表达式对象
        Expression expression = parser.parseExpression(spELString);
        // spring的表达式上下文对象
        EvaluationContext context = new StandardEvaluationContext();
        // 通过joinPoint获取被注解方法的形参
        Object[] args = joinPoint.getArgs();
        // 给上下文赋值
        for (int i = 0; i < args.length; i++) {
            context.setVariable(paramNames[i], args[i]);
        }
        // 表达式从上下文中计算出实际参数值
        /*如:
            @annotation(key="#student.name")
             method(Student student)
             那么就可以解析出方法形参的某属性值，return “xiaoming”;
          */
        return expression.getValue(context).toString();
    }
}      

3.定义切面类

@Aspect
@Component
public class SysLogAspect {
    @Autowired
    private LogService logService;

    @Autowired
    private HttpServletRequest request;

    @Pointcut("@annotation(com.ztri.common.annotation.SysLog)")
    public void logPointCut() {

    }

    @Around("logPointCut()")
    public Object around(ProceedingJoinPoint point) throws Throwable {
        long beginTime = System.currentTimeMillis();
        //执行方法
        Object result = point.proceed();
        //执行时长(毫秒)
        long time = System.currentTimeMillis() - beginTime;

        //保存日志
        saveSysLog(point, time);

        return result;
    }
    private void saveSysLog(ProceedingJoinPoint joinPoint, long time) {
        MethodSignature signature = (MethodSignature) joinPoint.getSignature();
        Method method = signature.getMethod();

        Log sysLog = new Log();
        sysLog.setTime(time);
        SysLog syslog = method.getAnnotation(SysLog.class);
        if (syslog != null) {
            //注解上的描述
            if (StrUtil.isNotBlank(syslog.value())) {
                sysLog.setOperation(syslog.value());
            }
            if (StrUtil.isNotBlank(syslog.spelValue())) {
                String spelValue = SpelUtil.generateKeyBySpEL(syslog.spelValue(), joinPoint);
                sysLog.setOperation(spelValue);
            }
        }
        //请求的方法名
        String className = joinPoint.getTarget().getClass().getName();
        String methodName = signature.getName();
        sysLog.setMethod(className + "." + methodName + "()");

        //请求的参数
        Object[] args = joinPoint.getArgs();
        try {
            String params = JSONUtil.toJsonStr(args);
            sysLog.setParams(params);
        } catch (Exception e) {

        }

        //设置IP地址
        sysLog.setIp(ServletUtil.getClientIP(request));
        UserAgent ua = UserAgentUtil.parse(request.getHeader("User-Agent"));
        sysLog.setBrowser(ua.getBrowser().toString());

        //保存系统日志
        logService.create(sysLog);
    }
}      

4.方法上使用日志注解

@ApiOperation("高级搜索(包含点击1.热门列表 2.更多跳转页面)")
    @PostMapping("searchData")
    @SysLog(spelValue = "'高级搜索' + #searchVo.keyWord")
    public ResponseEntity<Object> searchData(@RequestBody SearchVo searchVo) throws IOException {
        SearchDto searchDto = searchService.searchData(searchVo);
        return new ResponseEntity<>(searchDto, HttpStatus.OK);
    }

    @ApiOperation("登录授权")
    @PostMapping("/login")
    @SysLog("用户登录")
    public ResponseEntity<Object> login(@Validated(User.Create.class) @RequestBody LoginUser loginUser) {

        return ResponseEntity.ok(authInfo);
    }