解决static静态方法无法使用@Autowired注入的mapper/bean等元的问题

左手的ㄟ右手 2022-10-27 12:28 716阅读 0赞

### 解决static静态方法无法使用@Autowired注入的mapper/bean等元的问题 ###

*  1.@Autowired注入元素
 *  2.编写init方法
 *  3.完整代码

# 1.@Autowired注入元素 #

@Autowired注入元素时，得一次性注入两个元素，一个是静态的，一个不是静态的。

@Autowired
        private UserMapper testUserMapper; //非静态
        private static UserMapper userMapper; //静态
    
        @Autowired
        private RoleMapper testRoleMapper; //非静态
        private static RoleMapper roleMapper; //静态

# 2.编写init方法 #

编写init方法将非静态的元素初始化给静态元素，这样在静态方法中，就可以调用静态的那个元素。

@PostConstruct
        public void init() { 
            userRoleMapper = this.testUserRoleMapper;
            roleMapper = this.testRoleMapper;
        }

# 3.完整代码 #

@Component
    public class GetRoleByUserNameUtil { 
        @Autowired
        private UserRoleMapper testUserRoleMapper;
        private static UserRoleMapper userRoleMapper;
    
        @Autowired
        private RoleMapper testRoleMapper;
        private static RoleMapper roleMapper;
    
    
        @PostConstruct
        public void init() { 
            userRoleMapper = this.testUserRoleMapper;
            roleMapper = this.testRoleMapper;
        }
    
        public static String getRoleByUserName(String userName) { 
            UserRole userRole = new UserRole();
            Role role = new Role();
    
            //UserRole 的条件构造器
            QueryWrapper<UserRole> wrapper = new QueryWrapper<>();
            wrapper.inSql("userID",
                    "select userID from user where userName = '" + userName + "'");
    
            userRole = userRoleMapper.selectOne(wrapper);
    
            //Role的条件构造器
            QueryWrapper<Role> wrapper1 = new QueryWrapper<>();
            wrapper1.eq("roleID", userRole.getRoleID());
    
            role = roleMapper.selectOne(wrapper1);
            return role.getRoleName();
        }
    }