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

[email protected]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();
    }
}