问题描述
@MapperScan注解配置的一般是dao或者mapper的扫描包,一般用于数据库操作,里面类的一般都是接口,如果在dao层有其他接口,比如说@Service等就会报错
解决办法一
把service包移走,方法可行
解决办法二
不使用@MapperScan,在每个dao或者mapper里面加上注解@Mapper,方法可行
解决办法三
使用自定义注解,在mybatis的注解比较完善的情况下,就不用自己搞多少
1.创建注解@MyMapperScan
里面的属性全部抄袭@MapperScan
MapperScannerRegistrar换成自己的
@Retention(RetentionPolicy.RUNTIME)
@Target(ElementType.TYPE)
@Documented
@Import(MyMapperScannerRegistrar.class)
@Repeatable(MapperScans.class)
public @interface MapperScan {
String[] value() default {};
String[] basePackages() default {};
Class<?>[] basePackageClasses() default {};
Class<? extends BeanNameGenerator> nameGenerator() default BeanNameGenerator.class;
Class<? extends Annotation> annotationClass() default Annotation.class;
Class<?> markerInterface() default Class.class;
String sqlSessionTemplateRef() default "";
String sqlSessionFactoryRef() default "";
Class<? extends MapperFactoryBean> factoryBean() default MapperFactoryBean.class;
String lazyInitialization() default "";
}
MyMapperScannerRegistrar扫描注册器
这个类和mybatis的一模一样,唯一的不同就是MyClassPathMapperScanner是自己的扫描
public class MyMapperScannerRegistrar extends MapperScannerRegistrar {
private ResourceLoader resourceLoader;
/**
* {@inheritDoc}
*/
@Override
public void registerBeanDefinitions(AnnotationMetadata importingClassMetadata, BeanDefinitionRegistry registry) {
AnnotationAttributes annoAttrs = AnnotationAttributes.fromMap(importingClassMetadata.getAnnotationAttributes(MapperScan.class.getName()));
//这个是自己的
ClassPathMapperScanner scanner = new MyClassPathMapperScanner(registry);
// this check is needed in Spring 3.1
if (resourceLoader != null) {
scanner.setResourceLoader(resourceLoader);
}
Class<? extends Annotation> annotationClass = annoAttrs.getClass("annotationClass");
if (!Annotation.class.equals(annotationClass)) {
scanner.setAnnotationClass(annotationClass);
}
Class<?> markerInterface = annoAttrs.getClass("markerInterface");
if (!Class.class.equals(markerInterface)) {
scanner.setMarkerInterface(markerInterface);
}
Class<? extends BeanNameGenerator> generatorClass = annoAttrs.getClass("nameGenerator");
if (!BeanNameGenerator.class.equals(generatorClass)) {
scanner.setBeanNameGenerator(BeanUtils.instantiateClass(generatorClass));
}
Class<? extends MapperFactoryBean> mapperFactoryBeanClass = annoAttrs.getClass("factoryBean");
if (!MapperFactoryBean.class.equals(mapperFactoryBeanClass)) {
scanner.setMapperFactoryBean(BeanUtils.instantiateClass(mapperFactoryBeanClass));
}
scanner.setSqlSessionTemplateBeanName(annoAttrs.getString("sqlSessionTemplateRef"));
scanner.setSqlSessionFactoryBeanName(annoAttrs.getString("sqlSessionFactoryRef"));
List<String> basePackages = new ArrayList<String>();
for (String pkg : annoAttrs.getStringArray("value")) {
if (StringUtils.hasText(pkg)) {
basePackages.add(pkg);
}
}
for (String pkg : annoAttrs.getStringArray("basePackages")) {
if (StringUtils.hasText(pkg)) {
basePackages.add(pkg);
}
}
for (Class<?> clazz : annoAttrs.getClassArray("basePackageClasses")) {
basePackages.add(ClassUtils.getPackageName(clazz));
}
scanner.registerFilters();
scanner.doScan(StringUtils.toStringArray(basePackages));
}
/**
* {@inheritDoc}
*/
@Override
public void setResourceLoader(ResourceLoader resourceLoader) {
this.resourceLoader = resourceLoader;
}
}
MyClassPathMapperScanner
自己的扫描类基本也是mybatis的,就是在判断上面改动了一点点
public class MyClassPathMapperScanner extends ClassPathMapperScanner {
public MyClassPathMapperScanner(BeanDefinitionRegistry registry) {
super(registry);
}
@Override
protected boolean isCandidateComponent(AnnotatedBeanDefinition beanDefinition) {
boolean flag = super.isCandidateComponent(beanDefinition);
//包名带有Mapper的才会被mybatis代理
boolean mapper = beanDefinition.getBeanClassName().contains("Mapper");
return flag && mapper;
}
}
现在只需要用自己的扫描注解即可,用法和mybatis的一模一样
解决办法四
这个是针对第三点的,作者使用第三点的时候mybatis版本为3.4.6
mybatis-spring版本为1.3.2,spring版本为5.x
当mybatis版本为3.5.2的mybatis-spring版本为2.0.2的时候
MapperScannerRegistrar类扫描的方式发生了一点点变化,
还需要改写MapperScannerConfigurer类,其他的不变
完毕!
其他可以参考作者其他文章spring自定义组件扫描,模仿@MapperScan