浅谈基于SpringBoot实现一个简单的权限控制注解

import java.lang.annotation.*;

@Target({ElementType.PARAMETER}) // 注解可用于参数
@Retention(RetentionPolicy.RUNTIME) // 注解在运行时可由JVM读入
@Documented
public @interface Permission {
  String value() default "";
}

import lombok.Data;

@Data
public class User {
  private String id;
  private String name;

  private Set<String> permissions;
}

@Service
public class UserService {
  public boolean checkCreatePermission(@Permission("创建用户") User user) {
    return true;
  }

  public boolean checkDeletePermission(@Permission("删除用户") User user) {
    return true;
  }
}

@Aspect
@Component
public class PermissionAspect {
  // 需要修改为实际的 Service 所在的 Package
  @Pointcut("execution(public * tk.yubarimelon.MongoDemo.service.*.*(..))") 
  public void permissionCheck() {
  }

  @Around("permissionCheck()")
  public Object before(ProceedingJoinPoint joinPoint) throws Throwable {
    Object[] params = joinPoint.getArgs();
    // 获取方法，此处可将signature强转为MethodSignature
    MethodSignature signature = (MethodSignature) joinPoint.getSignature();
    Method method = signature.getMethod();

    // 获取参数注解，1维是参数，2维是注解
    Annotation[][] parameterAnnotations = method.getParameterAnnotations();
    for (int i = 0; i < parameterAnnotations.length; i++) {
      Object param = params[i];
      Annotation[] annotations = parameterAnnotations[i];
      if (!(param instanceof User) || annotations.length == 0) {
        continue;
      }
      for (Annotation annotation : annotations) {
        if (annotation.annotationType().equals(Permission.class)) {
          Permission permission = (Permission) annotation;
          User user = (User) param;
          if (CollectionUtils.isEmpty(user.getPermissions())) {
            log.error(user.getName() + " 无任何权限！");
            return false;
          }
          if (!StringUtils.hasLength(permission.value())) {
            log.error(joinPoint.getSignature().toString() + "权限设置异常");
            return false;
          }
          if (!user.getPermissions().contains(permission.value())) {
            log.error(joinPoint.getSignature().toString() +": "+user.getName() + " 无权限: " + permission.value());
            return false;
          }
          return joinPoint.proceed();
        }
      }
    }
    return joinPoint.proceed();
  }
}

@SpringBootTest
class ApplicationTests {

  @Autowired
  UserService userService;

  @Test
  void contextLoads() {
  }

  @Test
  void checkUser() {
    User user = new User();
    user.setName("小明");
    Set<String> permissions = new HashSet<>();
    permissions.add("创建用户");
    user.setPermissions(permissions);

    System.out.println("checkCreatePermission " + userService.checkCreatePermission(user));
    System.out.println("checkDeletePermission " + userService.checkDeletePermission(user));
  }
}