自定义@CurrentUser参数解析获取当前登录用户

HandlerMethodArgumentResolver简介
HandlerMethodArgumentResolver接口有以下两个方法

	//是否支持要转换的参数类型
	boolean supportsParameter(MethodParameter parameter);
	
	//如果支持的话进行转换
	@Nullable
	Object resolveArgument(MethodParameter parameter, @Nullable ModelAndViewContainer mavContainer,
			NativeWebRequest webRequest, @Nullable WebDataBinderFactory binderFactory) throws Exception;

自定义当前用户注解

/**
 * 当前用户注解
 */
@Retention(RetentionPolicy.RUNTIME)
@Target(value = ElementType.PARAMETER)
public @interface CurrentUser {

}

自定义参数解析

/**
 * 当前用户MethodArgumentResolver
 */
public class CurrentUserMethodArgumentResolver implements HandlerMethodArgumentResolver {

	@Inject
	private UserService userService;

	/**
	 * 是否支持参数
	 */
	@Override
	public boolean supportsParameter(MethodParameter methodParameter) {
		//判断方法参数是否带有@CurrentUser注解且参数类型为User或其子类
		return methodParameter.hasParameterAnnotation(CurrentUser.class) && User.class.isAssignableFrom(methodParameter.getParameterType());
	}

	/**
	 * 解析变量
	 */
	@SuppressWarnings("unchecked")
	@Override
	public Object resolveArgument(MethodParameter methodParameter, ModelAndViewContainer modelAndViewContainer, NativeWebRequest nativeWebRequest, WebDataBinderFactory webDataBinderFactory) throws Exception {
		//获取当前用户
		return userService.getCurrent();
	}

}

Springboot项目注册自定义解析器

@Configuration
public class MvcConfig implements WebMvcConfigurer {
	@Bean
	public CurrentUserMethodArgumentResolver currentUserMethodArgumentResolver() {
		return new CurrentUserMethodArgumentResolver();
	}

	@Override
	public void addArgumentResolvers(List<HandlerMethodArgumentResolver> argumentResolvers) {
		argumentResolvers.add(currentUserMethodArgumentResolver());
	}
	
	......
}

传统项目注册自定义解析器

<mvc:annotation-driven>
   <mvc:argument-resolvers>
      <bean class="xx.xx.xx.currentUserMethodArgumentResolver" />
   </mvc:argument-resolvers>
</mvc:annotation-driven>

使用@CurrentUser注解获取当前用户

@Controller
@RequestMapping("/test")
public class TestController {

	@GetMapping("/currentUser")
	public String test(@CurrentUser User currentUser) {
		......
	}

}