MapperScan初始化时，Spring的Enviroment注入错误导致属性无法注入

配置如下：

@Configuration
@MapperScan({"com.xxxx.**.mapper*", "${mybatis.scan.pkg1:com.temp1.**.mapper*}",
    "${mybatis.scan.pkg2:com.temp2.*.mapper*}"})
public class MybatisConfig {
}

在application.yml中注入属性：

mybatis.scan.pkg1=cn.test.**.mapper*

发现实际不生效。

经过代码跟踪： Spring在处理这个包转换时位置在：org.springframework.context.annotation.ClassPathScanningCandidateComponentProvider#resolveBasePackage

protected String resolveBasePackage(String basePackage) {
        return ClassUtils.convertClassNameToResourcePath(getEnvironment().resolveRequiredPlaceholders(basePackage));
    }

这个getEnvironment的属性来源于：org.springframework.context.annotation.ClassPathBeanDefinitionScanner#getOrCreateEnvironment

    /**
     * Get the Environment from the given registry if possible, otherwise return a new
     * StandardEnvironment.
     */
    private static Environment getOrCreateEnvironment(BeanDefinitionRegistry registry) {
        Assert.notNull(registry, "BeanDefinitionRegistry must not be null");
        if (registry instanceof EnvironmentCapable) {
            return ((EnvironmentCapable) registry).getEnvironment();
        }
        return new StandardEnvironment();
    }

根原因为： tk.mybatis.spring.annotation.MapperScannerRegistrar

@Override
    public void registerBeanDefinitions(AnnotationMetadata importingClassMetadata, BeanDefinitionRegistry registry) {
        AnnotationAttributes annoAttrs = AnnotationAttributes.fromMap(importingClassMetadata.getAnnotationAttributes(MapperScan.class.getName()));
        ClassPathMapperScanner scanner = new ClassPathMapperScanner(registry);

建议修改为：

@Override
    public void registerBeanDefinitions(AnnotationMetadata importingClassMetadata, BeanDefinitionRegistry registry) {
        AnnotationAttributes annoAttrs = AnnotationAttributes.fromMap(importingClassMetadata.getAnnotationAttributes(MapperScan.class.getName()));
        ClassPathMapperScanner scanner = new ClassPathMapperScanner(registry,true,this.enviroment);

或者，调用

scanner.setEnviroment(this.enviroment);

abel533 / Mapper

MapperScan初始化时，Spring的Enviroment注入错误导致属性无法注入 #828