Configuration类的@Value属性值为null

今天写的Configuration类的@Value属性值为null

@Configuration

public class MybatisConfigurer {

    @Value("${spring.datasource.url}")

    private String dbUrl;

    @Value("${spring.datasource.username}")

    private String username;

    @Value("${spring.datasource.password}")

    private String password;

    @Value("${spring.datasource.driver-class-name}")

    private String driverClassName;

    ……

    @Bean

    public MapperScannerConfigurer mapperScannerConfigurer() {

        MapperScannerConfigurer mapperScannerConfigurer = new MapperScannerConfigurer();

        mapperScannerConfigurer.setSqlSessionFactoryBeanName("sqlSessionFactoryBean");

        mapperScannerConfigurer.setBasePackage("com.abc.devide.demo.mapper");

        //配置通用Mapper，详情请查阅官方文档

        Properties properties = new Properties();

        properties.setProperty("mappers", MAPPER_INTERFACE_REFERENCE);

        properties.setProperty("notEmpty", "false");//insert、update是否判断字符串类型!='' 即 test="str != null"表达式内是否追加 and str != ''

        properties.setProperty("IDENTITY", "MYSQL");

        mapperScannerConfigurer.setProperties(properties);

        return mapperScannerConfigurer;

    }

}

问题的原因：

　　MapperScannerConfigurer实现了BeanDefinitionRegistryPostProcessor使得spring容器的执行的一些顺序问题，引起了上述@Value属性不能注入

解决方法：

　　将MapperScannerConfigurer单独放在一个@Configuration类下