springboot中使用aop

首先在pom文件中添加依赖

<dependency>

　　<groupId>org.springframework.boot</groupId>

　　<artifactId>spring-boot-starter-aop</artifactId> 

</dependency>

接着编写切面类

@Aspect//这个注解的作用是:将一个类定义为一个切面类
@Component//这个注解的作用：把切面类加入到IOC容器中
public class DemoAspect {

　　private static final Logger log = LoggerFactory.getLogger(DemoAspect .class);

　　/*@PointCut注解表示横切点，哪些方法需要被横切*/
　　/*切点表达式*/
　　@Pointcut("execution(public * com.simons.cn.springbootdemo.controller.*.*(..))")
　　public void demoAspect() {
　　}

　　/*@Before注解表示在具体的方法之前执行*/
　　@Before("demoAspect()")
　　public void before(JoinPoint joinPoint) {
　　　　log.info("前置切面before……");
　　　　ServletRequestAttributes requestAttributes = (ServletRequestAttributes) RequestContextHolder.getRequestAttributes();
　　　　HttpServletRequest request = requestAttributes.getRequest();
　　　　String requestURI = request.getRequestURI();
　　　　//String remoteAddr = request.getRemoteAddr(); //这个方法不一定能获取到用户的真实ip

　　　　String remoteAddr = getIpAddr();//自定义获取用户ip方法
　　　　String requestMethod = request.getMethod();
　　　　String declaringTypeName = joinPoint.getSignature().getDeclaringTypeName();
　　　　String methodName = joinPoint.getSignature().getName();
　　　　Object[] args = joinPoint.getArgs();
　　　　log.info("请求url=" + requestURI + ",客户端ip=" + remoteAddr + ",请求方式=" + requestMethod + ",请求的类名=" + declaringTypeName + ",方法名=" + methodName + ",入参=" + args);
　　}

　　/*@After注解表示在方法执行之后执行*/
　　@After("demoAspect()")
　　public void after() {
　　　　log.info("后置切面after……");
　　}

　　/*@AfterReturning注解用于获取方法的返回值*/
　　@AfterReturning(pointcut = "demoAspect()", returning = "object")
　　　　public void getAfterReturn(Object object) {
　　　　　　log.info("afterReturning={}", object.toString());
　　　　}
　　}

/** 
     * 获取用户真实IP地址，不使用request.getRemoteAddr()的原因是有可能用户使用了代理软件方式避免真实IP地址, 
     * 可是，如果通过了多级反向代理的话，X-Forwarded-For的值并不止一个，而是一串IP值 
     *  
     * @return ip
     */
    private String getIpAddr(HttpServletRequest request) {
        String ip = request.getHeader("x-forwarded-for"); 
        System.out.println("x-forwarded-for ip: " + ip);
        if (ip != null && ip.length() != 0 && !"unknown".equalsIgnoreCase(ip)) {  
            // 多次反向代理后会有多个ip值，第一个ip才是真实ip
            if( ip.indexOf(",")!=-1 ){
                ip = ip.split(",")[0];
            }
        }  
        if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) {  
            ip = request.getHeader("Proxy-Client-IP");  
            System.out.println("Proxy-Client-IP ip: " + ip);
        }  
        if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) {  
            ip = request.getHeader("WL-Proxy-Client-IP");  
            System.out.println("WL-Proxy-Client-IP ip: " + ip);
        }  
        if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) {  
            ip = request.getHeader("HTTP_CLIENT_IP");  
            System.out.println("HTTP_CLIENT_IP ip: " + ip);
        }  
        if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) {  
            ip = request.getHeader("HTTP_X_FORWARDED_FOR");  
            System.out.println("HTTP_X_FORWARDED_FOR ip: " + ip);
        }  
        if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) {  
            ip = request.getHeader("X-Real-IP");  
            System.out.println("X-Real-IP ip: " + ip);
        }  
        if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) {  
            ip = request.getRemoteAddr();  
            System.out.println("getRemoteAddr ip: " + ip);
        } 
        System.out.println("获取客户端ip: " + ip);
        return ip;  
    }
关于为什么要这样写才能获取用户真实ip，参见https://www.cnblogs.com/xiaoxing/p/6565573.html