文章内容
AOP切面获取自定义参数注解:@Target(ElementType.PARAMETER)
1、创建自定义参数注解
import java.lang.annotation.ElementType;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.Target;
@Target(ElementType.PARAMETER)
@Retention(RetentionPolicy.RUNTIME)
public @interface User {
}
这里@Target中的类型用的是PARAMETER,因为我这里的注解要用到参数中。比如:
@GetMapping("/test")
public R myCustomProduct(@User UserVo userVo) {
return R.ok(userVo);
}
2、编写自定义注解解析器
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.core.MethodParameter;
import org.springframework.data.redis.core.RedisTemplate;
import org.springframework.stereotype.Component;
import org.springframework.web.bind.support.WebDataBinderFactory;
import org.springframework.web.context.request.NativeWebRequest;
import org.springframework.web.context.request.RequestAttributes;
import org.springframework.web.method.support.HandlerMethodArgumentResolver;
import org.springframework.web.method.support.ModelAndViewContainer;
@Component
public class UserHandlerMethodArgumentResolver implements HandlerMethodArgumentResolver {
@Autowired
RedisTemplate<String, Object> redisTemplate;
@Override
public boolean supportsParameter(MethodParameter methodParameter) {
// return methodParameter.getParameterType().isAssignableFrom(UserVo.class) && methodParameter.hasParameterAnnotation(User.class);
return methodParameter.hasParameterAnnotation(User.class);
}
@Override
public Object resolveArgument(MethodParameter methodParameter, ModelAndViewContainer modelAndViewContainer, NativeWebRequest nativeWebRequest, WebDataBinderFactory webDataBinderFactory) throws Exception {
//获取用户信息
String openId = nativeWebRequest.getHeader("uuid");
UserVo user = (UserVo) redisTemplate.opsForValue().get(RedsKeyConstant.SESSION_USER_UUID+openId);
if(user==null||openId==null) {
return null;
}
return user;
}
}
3、实现WebMvcConfigurer接口,重写addArgumentResolvers方法配置解析器
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.context.annotation.Configuration;
import org.springframework.web.method.support.HandlerMethodArgumentResolver;
import org.springframework.web.servlet.config.annotation.WebMvcConfigurer;
import java.util.List;
@Configuration
public class WebMvcConfig implements WebMvcConfigurer {
@Autowired
private UserHandlerMethodArgumentResolver userHandlerMethodArgumentResolver;
@Override
public void addArgumentResolvers(List<HandlerMethodArgumentResolver> argumentResolvers) {
argumentResolvers.add(userHandlerMethodArgumentResolver);
}
}
4、创建切面
import org.aspectj.lang.ProceedingJoinPoint;
import org.aspectj.lang.Signature;
import org.aspectj.lang.annotation.*;
import org.aspectj.lang.reflect.MethodSignature;
import org.springframework.stereotype.Component;;
import java.lang.annotation.Annotation;
import java.lang.reflect.Method;
@Aspect
@Component
public class LoginUserTokenAspect {
@Around("within(com.ntan520.controller.PubController) || within(com.ntan520.controller.HomeController) ")
public Object run(ProceedingJoinPoint joinPoint)throws Throwable{
// System.out.println("aspect is run!!");
Object[] args = joinPoint.getArgs();
// 方法签名
Signature signature1 = joinPoint.getSignature();
// 获取的是代理类的method对象
Method method1 = ( (MethodSignature)signature1 ).getMethod();
// 这个方法才是目标对象上有注解的方法
Method realMethod = joinPoint.getTarget().getClass().getDeclaredMethod(signature1.getName(), method1.getParameterTypes());
// 取出对应的注解
String name = "";
int num = -1;
Annotation[][] parameterAnnotations = realMethod.getParameterAnnotations();
A: for (Annotation[] annotations : parameterAnnotations) {
for (Annotation annotation : annotations) {
//获取注解名
name = annotation.annotationType().getSimpleName();
num = num + 1;
if (name.equals("User")){
break A;
}
}
}
//获取注解
//User user = method.getAnnotation(User.class);
if(name.equals("User")){
UserVo userVo = (UserVo)args[num];
if(userVo == null || userVo.getId() == null){
//未登录需要告诉用户你未登录
return R.failed("401","请重新获取用户信息!");
}else {
//已经登录的继续处理业务
return joinPoint.proceed(args);
}
} else {
//没有这个注解的不验证登录,继续处理业务
return joinPoint.proceed(args);
}
}
}