4、组件注册-自定义TypeFilter指定过滤规则

4、组件注册-自定义TypeFilter指定过滤规则

4.1 FilterType.ANNOTATION 按照注解方式

4.2 FilterType.ASSIGNABLE_TYPE 按照给定的类型

@ComponentScan.Filter(type = FilterType.ASSIGNABLE_TYPE, classes = {BookService.class})

4.3 FilterType.ASPECTJ 按照ASPECTJ表达式

4.4 FilterType.REGEX 按照正则表达

4.5 FilterType.CUSTOM 按照自定义规则

@ComponentScan(value = "com.hw.springannotation", useDefaultFilters = false,
        includeFilters = {
//        @ComponentScan.Filter(type = FilterType.ANNOTATION, classes = {Controller.class}),
//                @ComponentScan.Filter(type = FilterType.ASSIGNABLE_TYPE, classes = {BookService.class}),
                @ComponentScan.Filter(type = FilterType.CUSTOM, classes = {MyTypeFilter.class})
        }
)       // 指定只扫描

• 创建MyTypeFilter类,需要实现TypeFilter 接口，重写match()方法

package com.hw.springannotation.config;

import org.springframework.core.io.Resource;
import org.springframework.core.type.AnnotationMetadata;
import org.springframework.core.type.ClassMetadata;
import org.springframework.core.type.classreading.MetadataReader;
import org.springframework.core.type.classreading.MetadataReaderFactory;
import org.springframework.core.type.filter.TypeFilter;

import java.io.IOException;

/**
 * @Description TODO
 * @Author hw
 * @Date 2018/11/27 18:49
 * @Version 1.0
 */
public class MyTypeFilter implements TypeFilter {
    /**
     * Determine whether this filter matches for the class described by
     * the given metadata.
     *
     * @param metadataReader        the metadata reader for the target class    读取到得当前正在扫描的类的信息
     * @param metadataReaderFactory a factory for obtaining metadata readers    一个可以探索其他类信息的工厂类
     *                              for other classes (such as superclasses and interfaces)
     * @return whether this filter matches
     * @throws IOException in case of I/O failure when reading metadata
     */
    public boolean match(MetadataReader metadataReader, MetadataReaderFactory metadataReaderFactory) throws IOException {
        // 获取当前类的注解信息
        AnnotationMetadata annotationMetadata = metadataReader.getAnnotationMetadata();
        // 获取当前类信息
        ClassMetadata classMetadata = metadataReader.getClassMetadata();
        // 获取当前类的资源（类的路径）
        Resource resource = metadataReader.getResource();

        String className = classMetadata.getClassName();
        System.out.println("----" + className);

        if (className.contains("er")) {
            return true;
        }
        return false;
    }
}